Proceedings of the 1991 Exclusive 

Economic Zone Symposium on 

Mapping and Research: Working 

Together in the Pacific EEZ 

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Proceedings of the 1991 Exclusive 

Economic Zone Symposium on 

Mapping and Research: Working 

Together in the Pacific EEZ 

MILLINGTON LOCKWOOD, National Oceanic and Atmospheric Administration, and 

BONNIE A. McGREGOR, U.S. Geological Survey, EDITORS 

Sponsored by the USGS-NOM joint Office 

for Mapping and Research in the EEZ and the 

Association of American State Geologists 

Meetings held at the Portland Hilton, 

Portland, Oregon, November 5-7, 1991. 

Department of the Interior 

U.S. Geological Survey 

Department of Commerce 

National Oceanic and 

Atmospheric Administration 

U.S. GEOLOGICAL SURVEY CIRCULAR 1092 
U.S. DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, Jr., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Any use of trade, product, or firm names in this publication is for descriptive 

purposes only and does not imply endorsement by the U.S. Government 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1992 

Free on application to the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center, Box 25286 

Denver, CO 80225 

Library of Congress Cataloging in Publication Data 

Exclusive Economic Zone Symposium on Mapping and Research (1991 : Portland, Oreg.) 

Proceedings of the 1991 Exclusive Economic Zone Symposium on Mapping 

and Research : working together in the Pacific EEZ I Millington Lockwood 

and Bonnie A. McGregor, editors. 

p. em. - (U.S. Geological Survey circular ; 1092) 

Includes bibliographical references. 

1. Ocean bottom-Pacific Coast (U.S.)-Maps-Congresses. I. Lockwood, 

Millington. II. McGregor, Bonnie A. Ill. Title. IV. Series. 

GC87.E93 1991 

551.46'08343-dc20 92-30910 

CIP 
CONTENTS 

Symposium Introduction and Overview 

Gary W. Hill and Millington Lockwood 1 

The Role of the USGS in EEZ Mapping and Research 

Doyle G. Frederick 3 

NOAA's EEZ Mapping Program-Challenges and Choices 

John Carey 9 

Mapping the Ocean Floor from the DMA-Defense Hydrographic Initiative Perspective 

Thomas E. Klocek 12 

Pacific Mapping Program 

Narendra K. Saxena 14 

Ocean Mapping-A Canadian Perspective 

John E. Hughes Clarke, Larry A. Mayer, David E. Wells, and Gerard Costello 20 

Commercial Seabed Surveys in the U.S. EEZ and Issues Associated with the 

Distribution of These Data 

Donald M. Hussong 29 

Cenozoic Geologic History of the Oregon and Washington Continental Margin 

Parke D. Snavely, Jr. 30 

Strike-Slip Faults Associated with the Cascadia Convergence Zone off Oregon 

LaVerne D. Kulm 37 

The NOAA Vents Program-Interdisciplinary Studies of Hydrothermal Processes on 

the Juan de Fuca Ridge 

Robert Embley 38 

Joint SIO-NOAA Geophysical Studies on the Southern Juan de Fuca Ridge 

John A. Hildebrand, Spahr C. Webb, and Christopher G. Fox 39 

NOAA's Multibeam Bathymetric Surveys and Products off Hawaii and the Northeast 

Pacific Margin 

Gerald B. Mills and Richard B. Perry 40 

GLORIA Mapping in the Pacific Basin 

David A. Cacchione and James V. Gardner 45 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 

Ralph G. Currie, Earl E. Davis, and Brian S. Sawyer 49 

Scripps Institution's Multibeam and Magnetic Mapping West of California and Baja 

California 

Peter Lonsdale 62 

Deep-Towed Swath Bathymetry by an Interferometric Isophase Method 

Arthur St. C. Wright 63 

Oregon's Ocean Plan, an Emerging State Ocean Program and Information Needs 

D. Eldon Hout 70 

Resource Potential of Offshore Placer Deposits 

Clifford E. McClain 71 

A Case Study of the Norton Sound Alaska Marine Mineral Lease Sale Process 

Anthony C. Giordano 72 

Contents Ill 
IV Contents 

Geological and Biological Investigations of Oregon's Nearshore Placer Deposits 

Richard M. Starr and Dennis L. Olmstead 77 

Offshore Geology of the Gulf of the Farallones Region Project-A Model for 

Environmental Research on Continental Margins off Major Urban Areas and in 

National Marine Sanctuaries 

Herman A. Karl 86 

The Minerals Management Service's Implementation of the North American Datum of 

1983 in the EEZ 

Alice R. Drew and Paul H. Rogers 98 

Dissemination of NOAA-NOS EEZ Multibeam Bathymetric Data 

Paul J. Grim 102 

Application of Drainage Extraction to NOAA Gridded Bathymetry of the U.S. 

Continental Margin 

Lincoln F. Pratson and William B.F. Ryan 110 

Bridging the Gap-Creating Nearshore Bathymetric Maps from Multibeam Swath 

Sonar Systems and Conventional Hydrographic Data 

Stephen P. Matula 118 

Processing EEZ Data in a Marine Geographic Information System 

Gail Langran and Donna J. Kall 127 

Defense Mapping Agency's Defense Hydrographic Initiative and the DOD Bathymetric 

Digital Data Library and Hydrographic Source Assessment System 

James Patrick Moran 130 

COAP-A New Approach to Ocean Data Distribution 

William G. Schramm 131 

Geology and Hydrothermal Deposits at Escanaba Trough, Southern Gorda Ridge 

Randolph A. Koski, Janet L. Morton, Stephanie L. Ross, and Robert A. 

Zierenberg 132 

West Coast GLORIA on CD-ROM 

Joseph M. Coddington 136 

The Use of Geographical Information Systems (GIS) to Facilitate Ocean Site 

Designation for Disposal of Harbor Dredged Materials 

Robert K. Hall, Allan Y. Ota, Norman M. Maher, and Gregory Gabel 137 

Deep Sea Rock Drill-Beginning a New Era of Sea-Floor Sampling 

Brian Halbert 144 

Geologic Framework of the Washington-Oregon Continental Shelf-Preliminary 

Findings 

Deborah J. Crans wick and Kenneth A. Piper 146 

Pacific EEZ Marine Minerals Activities of the Minerals Management Service 

Roger V. Amato 152 

Appendix 1-List of Registrants 161 

Appendix 2-1991 Exclusive Economic Zone Symposium Program Agenda 166 

Appendix 3-Charter for Coordination of Federal Exclusive Economic Zone Mapping 

and Research Programs 190 

Appendix 4-Exclusive Economic Zone of the United States of America, A 

Proclamation by the President of the United States of America 191 
CONVERSION FACTORS 

Multiply 

inch (in) 

foot (ft) 

mile (mi) 

nautical mi (nmi) 

millimeter (mm) 

centimeter (em) 

meter (m) 

kilometer (km) 

square foot (ft2

) 

square mile (mi2

) 

square nautical mile (nme) 

square centimeter ( cm2

) 

square kilometer (km2

) 

hectare (ha) 

gallon (gal) 

kilogram (kg) 

metric ton (1 ,000 kg) 

By 

Length 

25.4 

0.3048 

1.609 

1.852 

0.03937 

0.3937 

3.28 

0.6214 

0.5400 

Area 

0.0929 

2.590 

3.423 

0.1550 

0.3861 

2.471 

Volume 

3.785 

Mass 

2.205 

1.102 

Acceleration 

To obtain 

millimeter (mm) 

meter (m) 

kilometer (km) 

kilometer (km) 

inch (in) 

inch (in) 

foot (ft) 

mile (mi) 

nautical mile (nmi) 

square meter (m2

) 

square kilometer (km2

) 

square kilometer (km2

) 

square inch (in2

) 

square mile (mi2

) 

acre 

liter (L) 

pounds avoirdupois (lb avdp) 

ton (2,000 pounds) 

milligal (mGal) 0.00001 meter per second squared (m/s2

) 

Age designations.-The time of a geologic event and the age of an epoch boundary are 

expressed as Ma (mega-annum), and intervals of time are expressed as m.y. (million years). Both 

terms mean 1,000,000 years, or years X 106 • For example, sediments were deposited at 85 Ma 

(85X 106 years before 1950 A.D.), and the deposition continued for the next 2 m.y. 

Abbreviations 

hertz (Hz)=A unit of frequency of a periodic process equal to one cycle per second. 

kilohertz (kHz)=A unit of frequency equal to one thousand hertz. 

Contents V 

Proceedings of the 1991 Exclusive Economic 

Zone Symposium on Mapping and Research: 

Working Together in the Pacific EEZ 

Millington Lockwood and Bonnie A. McGregor, editors 

Symposium Introduction and Overview 

Gary W. Hill 

U.S. Geological Survey 

Joint Office for Mapping and Research 

Millington Lockwood 

National Oceanic and Atmospheric Administration 

Joint Office for Mapping and Research 

The 1991 Exclusive Economic Zone (EEZ) Symposium was held at the Portland Hilton, in Portland, Oreg., on 

November 5-7, 1991. The meeting was sponsored by the 

National Oceanic and Atmospheric Administration 

(NOAA) and the U.S. Geological Survey (USGS) Joint 

Office for Mapping and Research (JOMAR) and the Association of American State Geologists. Local host for the 

meeting was the Oregon State Geologist. Over 100 individuals from 10 Federal Departments/Bureaus, State governments, universities, and the private sector attended the 

meeting. Five individuals from foreign nations were in 

attendance. Appendix 1 lists those who registered for the 

symposium. 

This was the 5th in a series of meetings held biennially since the issuance of the EEZ Proclamation in 1983. It 

was the first held outside the Washington, D.C., metropolitan area. The purpose of this meeting was to communicate 

to the user community results of mapping and research in 

the EEZ, to determine priorities for future activities, and to 

continue to develop cooperative relations with other Federal 

Agencies, academia, and the private sector. The Northwest 

area was selected because of the current sea-floor mapping 

activity and marine geological research community in that 

region since the initiation of the USGS-NOAA mapping 

Manuscript approved for publication, July 27, 1992. 

activities that occurred there in the early years immediately 

following the issuance of the EEZ Proclamation. 

There were 33 presentations given at the meeting; 

several presentations had extensive displays of maps and 

sea-floor research. Topics included bathymetric and sonar 

mapping of the coastal waters of Oregon-Washington, 

Alaska and Hawaii, research on the Oregon continental 

margin, assessments of mineral resource potential in the 

coastal waters, and development of geographic information 

systems. In addition to the scientific presentations, there 

were approximately 20 exhibits, or poster-type displays, 

showing results of mapping and research activities. Approximately seven of these displays were computer based. 

Appendix 2 is a copy of the symposium program. 

This Proceedings volume consists of prepared papers 

submitted by symposium participants. They have been 

lightly edited for conformity and minor grammatical corrections. In a few cases, a full paper was not submitted, but 

an abstract of the presentation is included. In these cases, 

the author should be contacted for details. 

In addition to the formal symposium, the National 

Research Council's (NRC) Committee on EEZ Information 

Needs held a 1/z-day workshop on issues associated with the 

management, access, and dissemination of EEZ sea-floorrelated data. This is part of an ongoing multiyear effort by 

the NRC to provide advice to JOMAR on the information 

needs of the private sector, academic community, and State 

Symposium Introduction and Overview 
agencies. Results of the NRC's efforts have been published 

in two interim reports; a final report is expected by 

mid-1992. 

While there was no attempt to draw specific conclusions or recommendations from the meeting, several observations and comments could be concluded, as follows: 

1. Continued strong interest was expressed by participants 

in obtaining results of NOAA and USGS surveys. 

2. Data must be available in digital form, and participants 

voiced concern about data management. 

3. Highest priority for data collection in order to meet user 

needs is in the upper continental slope and shelf regions. 

4. This symposium (more than others) had active partici2 Proceedings, 1991 EEZ Symposium on Mapping and Research 

pation by the Department of the Defense, especially the 

Defense Mapping Agency and the U.S. Naval Oceanographic Office. 

5. Higher percentage of attendees (than previous symposia) 

were from the academic sector and private industry. A 

willingness to develop cooperative projects was 

expressed. 

The success of the 1991 EEZ Symposium was due 

mainly to the efforts of the co-sponsor, the Oregon Department of Geology and Minerals Industry (DOG AMI), and the 

Oregon State Geologist, Donald Hull. Gregory McMurray of 

DOGAMI was the coordinator for the symposium. 
The Role of the USGS in EEZ Mapping and Research 

Doyle G. Frederick 

U.S. Geological Survey 

Today, I want to briefly discuss the Geological 

Survey's program and tell you especially about the scientific partnership we all have enjoyed that was absolutely 

necessary to accomplish the scientific advances we have 

seen, and one that is needed as we plan many new activities. 

I hesitate to talk here in detail about these programs because 

you're the folks who know them best and who have made 

them work. 

Director Dallas Peck sends his regards. I think this is 

the first Exclusive Economic Zone (EEZ) Symposium he 

has missed. He is in the Antarctic with the Administrator of 

the National Oceanic and Atmospheric Administration 

(NOAA), the Under Secretary of Commerce for Oceans and 

Atmosphere, John Knauss. They are taking a trip with the 

Director of the National Science Foundation and several 

other dignitaries, so it will be interesting for all of them. 

Donald Hull, the State Geologist of Oregon, already 

mentioned the 1983 EEZ Proclamation of then-President 

Reagan. Of course, there was considerable activity before 

that time with interest focused largely on The Law of the 

Sea and issues relating to how the United States deals with 

the territory offshore. In particular, the minerals-related 

issues were a hot topic at that time, and, as I recall, debate 

in the Administration revolved around the issue of mineral 

resources in what we now know as the EEZ and around the 

question of how to deal with that in a balanced way. We 

strove to understand what the resources are and how we 

could begin a reasonable program that looked at all the 

issues in balance. A lot of topics debated in the framework 

of The Law of the Sea focused on the EEZ off the West 

Coast. As a result of this considerable debate, a decision was 

made to proceed with the EEZ Proclamation. Back then, 

many of you said that we really didn't know much about the 

EEZ, and I recall conversations in which people said that 

we know as much about the back side of the moon as we do 

about much of the EEZ. 

You and others, however, were able to convince the 

decisionmakers that we really must learn more about the 

EEZ. We need to place our efforts on developing a program 

that takes a look at the EEZ through systematic research and 

a comprehensive mapping program. The principal questions 

we needed to answer were the following: What do we have 

in the EEZ, and how can we make it work to our benefit? 

Moreover, how do we answer questions about the quality, 

quantity, and location of offshore nonrenewable resources, 

and how do we address legitimate social issues relating to 

the environment and hazards? It was a fairly significant task 

to undertake. 

The U.S. Geological Survey (USGS) in cooperation 

with scientists from the United Kingdom (UK) fortunately 

came up with the idea of Geologic LOng-Range Inclined 

Asdic (GLORIA) surveys and an overall approach that was 

affordable in terms of money and time. This technology 

provided a means to achieve a systematic look at the EEZ. 

While the USGS and the UK folks take much credit, we 

also must credit our colleagues in other Federal Agencies, in 

particular NOAA, and the Bureaus of the Department of the 

Interior, including the Minerals Management Service 

(MMS), and many State agencies. There developed a 

common understanding that EEZ surveys are a reasonable 

idea and that we should proceed. 

While a completed GLORIA survey would yield a lot 

of good information, it was only a beginning and would not 

answer all questions. So, we had to begin by setting some 

basic objectives. Let us make sure that we pause to take a 

hard look at some of the real issues. You will hear many of 

those discussions in the technical and poster sessions over 

the next couple of days. And, while we are collecting the 

data, let us make sure we pause to take a look at what they 

really mean. Then, let us collect additional data and 

undertake additional research to make sure that we can 

better interpret the data already gathered. You will see some 

of these results in poster sessions and hear about other 

significant accomplishments in the technical sessions. 

As you know, we have now finished the 50-State 

portion of the EEZ (fig. 1), and Dave Cacchione will 

describe some results of these surveys later today. From our 

point of view, these are all significant accomplishments for 

the agencies involved, but the credit goes to not just the 

USGS folks but to all of you who have cooperated in the 

programs. The GLORIA surveys represent an excellent data 

base, and it is a good place to start. It gives us a lot of 

information, but not all, as you will see, so it really is only 

a good place to start. While we pause to commemorate this 

The Role of the USGS in EEZ Mapping and Research 3 
Figure 1. GLORIA surveying that has been completed so far, and proposed surveying for 1994---96. 

fairly significant accomplishment, we also ought to renew 

our commitments to continue studying this important part of 

our country. 

Today, I want to describe some of our accomplishments related directly to the EEZ as well as to some of the 

things we have learned from studies of EEZcrelated issues. 

I have included here results of followup programs, some of 

which are related directly to the EEZ and some of which are 

only peripherally related to the EEZ, but nonetheless 

significant to the overall program. And again, these are not 

just USGS programs but are projects of the USGS-NOAA 

Joint Office and also products of the structure that we have 

established for coordination amongst the Federal Agencies 

to receive input from State and local government agencies, 

from universities, and from the private sector as well. 

One of things that this GLORIA community decided 

early on was that the surveys may be well and good, but we 

have to figure out a way to get the data and results out in a 

timely way to the people who need to have them and make 

sure that the information is available and usable . We 

decided to publish a set of GLORIA atlases, and to date we 

have finished four. The western conterminous U.S . EEZ 

was the first of those atlases, and we have just finished the 

Bering Sea and East Coast. Many others are underway: The 

4 Proceedings, 1991 EEZ Symposium on Mapping and Research 

first of the three Hawaiian Island atlases will be published in 

1993, and the second of three Alaskan atlases will be 

finished in 1993. Joe Cottington has a display of the 

completed atlases, so if you want to know more details 

about those and the schedule for future atlases, drop by his 

display. 

I mentioned that the GLORIA surveys on the EEZ 

were only a good start. Some consider it to be a reconnaissance, but there are a lot of new things that we learned from 

the GLORIA surveys. For example, we found out just how 

large lava flows and landslide features can be off the 

Hawaiian Islands (fig. 2), and this represents a significant 

increase in our knowledge. Robin Holcomb and Dave 

Drake will discuss this topic, and there is a poster display of 

the GLORIA mosaic for Hawaii; they also have a display of 

the GLORIA mosaic around Johnston Island. 

Now, let me turn to some additional topics in the 

Pacific EEZ. Gorda Ridge investigations have provided 

opportunities for a very successful and continuing cooperative program amongst the USGS, NOAA, the Bureau of 

Mines, the U.S. Navy (USN), and the Army Corps of 

Engineers (Corps). We will hear from the MMS a little bit 

later on minerals-related issues on the Gorda Ridge, in 

terms of what we have learned and what is yet to be 
Figure 2. Mosaic of Hawaii imaging showing lava flows (off east point of Hawaii) and several large landslides (fan-shaped 

region north of Molokai). 

accomplished in this area. Preliminary studies have given us 

a reasonable two-dimensional understanding of the formation of sediment-hosted massive sulfides on Gorda Ridge, 

and with current drilling activities, we hope to get a better 

three-dimensional understanding of the mineralization process. Of course, this could lead to useful analogies to sulfide 

deposits on land and a better discovery process. 

Another area of interest is the Farallons Marine 

Sanctuary, and it is one of our focal studies in the EEZ (fig. 

3). Once again, this is a joint project with NOAA, the USN, 

the Corps, the Environmental Protection Agency (EPA), 

and the USGS. 

This is a many-faceted issue involving a marine 

sanctuary area encompassing an old dumpsite for radioactive waste that may tum out to be fairly significant. There is 

also an issue of dredge-spoil dumping from the San Francisco Bay area, and the problem is, of course, understanding sediment transport and deposition. The challenge is to 

make some real and important decisions that affect the 

ability of government agencies to dredge, dump, and 

otherwise take advantage of easy access to the environment. 

We will hear a great deal more tomorrow from Herman Karl 

about the Farallons, and you can see his and Tom Chase's 

poster display. Robert Hall also has a poster display 

showing how we can use geographic information systems to 

achieve a new perspective. One of my favorite applications 

is pulling up the geographic data and related information in 

such a way that we can analyze and present results so that 

people in general, not only the scientists, can understand 

them. 

Shifting all the way to the other coast, just briefly, I 

also want to mention our work in Boston Harbor, which you 

have heard about perhaps during campaigns of the last 

presidential election. It is a big issue for us in terms of being 

able to know what happens to pollutants and other contaminants in sediments resulting from sewage discharge. 

Again, you know better than I know what the issues are and 

how you can contribute to their solutions. We are working 

in cooperation with several agencies including EPA and the 

State of Massachusetts to evaluate the effects of this effluent 

and to discover how contaminants are transported and 

deposited with the sediments in Boston Harbor. Many of the 

same issues that we are talking about in the Farallons are 

repeated here, although this is probably a more direct, 

you-have-to-solve-it-quickly kind of an issue. Both the 

Congress and the Executive Branch, as well as the State of 

The Role of the USGS in EEZ Mapping and Research 5 
Figure 3. Map of Farallons project area, California. 

Massachusetts, are carefully exammmg this issue. We 

began the work as a cooperative program with State 

agencies funded at a very low level; shortly thereafter, the 

Congress became interested and actually added funds to the 

USGS's budget to expand the investigations. This is the 

kind of program that we envision in the Farallons and other 

municipal offshore areas as significant focal studies of our 

marine program. 

We have recently completed a geophysical study of 

San Francisco Bay (fig. 4). This includes a seismic survey 

that is another part of our overall program in the EEZ, and 

it emphasizes the value of good information. It results from 

a cooperative effort between the USGS, the University of 

California (Berkeley), Lawrence Berkeley Labs, and Stanford University. Here the task is to examine deep fault 

geometry to determine if faults are linked at depth and if 

6 Proceedings, 1991 EEZ Symposium on Mapping and Research 

their connection to deeper plate boundaries is an important 

factor in understanding how and when stress is transferred 

during an earthquake cycle. Some of the initial success has 

centered on establishing a cooperative effort that produced 

results in a reasonable time, at reasonable costs, and 

without a lot of fuss. 

This is an excellent example of the cooperation 

among several scientific agencies and with the San Francisco Bay area transit system management, which helped 

with logistics. These examples reflect the theme you heard 

earlier and that you will hear continually throughout this 

symposium: We cannot solve these problems by ourselves, 

and we must work together to achieve success. 

In the EEZ in the Gulf of Mexico (fig . 5), we have 

made an interpretation of the development of the fan off the 

Mississippi River Delta from a broad look at GLORIA 
Figure 4. Area of fault study in the San Francisco Bay region. 

images. These images reveal that the fan comprises several 

structures; that is, it is not just one large fan, but there are 

many deposits, and individual channels can be distinguished over a broad area. A SeaMARC lA image of the fan 

provides detailed information that allows us to develop new 

models of mass movement of sediment at low angles. 

An essential element of our efforts is our ability to put 

geologic, physical, topographic, and remote sensing imagThe Role of the USGS in EEZ Mapping and Research 7 
Figure 5. Interpretation of the development of the Mississippi River Delta from GLORIA images. 

8 Proceedings, 1991 EEZ Symposium on Mapping and Research 

ery together to make interpretations and provide visualization. There are many examples of the so-called "gee whiz" 

approach to displaying data in an understandable manner, 

such as GLORIA imagery draped over bathymetry, and you 

can see many of these examples in poster displays here. 

Visualization is indeed an exciting aspect of our programs. 

The theme of the Marine Board session stresses data and 

information management, how we collect display data, and 

what the standards are. How do the data fit together so that 

we can manipulate them in such a way that the information 

gleaned is usable and meaningful to a wide variety of users? 

How can we display data and information so that we can 

have an impact on the people who make decisions about our 

programs and budgets? As we prepare results of our 

research for public consumption, we need to hear these 

decisionmakers say: "Now I see what you're talking about; 

this information really is valuable in understanding what's 

going on." 

We said that we have accomplished a great deal 

especially since the Presidential Proclamation of the Exclusive Economic Zone, building on results of much work 

done before then. Mapping the EEZ has taken a concentrated effort on the parts of many Federal and State 

government agencies. Today, we are pleased to have 

finished our GLORIA mapping of the U.S. portion of the 

EEZ, but we do plan to continue the mapping until it is 

complete. The next thrust will begin in 1994 when we will 

start surveying the U.S. Trust Territories in a planned 3-yr 

program. As significant an accomplishment as this may be, 

we have significant concerns remaining related to the 

fishing industry, marine sanctuaries, dredge material dumping in areas where it can be done safely, hazards to 

communications links, distribution of resources, and conservation and environmental questions throughout the EEZ. 

There is much to be done still, and we at the USGS are 

pleased to have been part of this very, very exciting 

program over the last several years, and we look forward to 

the second half of this decade. 

So again, I am pleased to be with you here today, as 

I know it is going to be a good session. We appreciate the 

contributions that all of you have made to what I consider to 

be a very successful program that will continue to be 

successful. We applaud the partnership because it is essential as we find better ways to continue the cooperation. 
NOAA's EEZ Mapping Program-Challenges and Choices 

john Carey 

National Oceanic and Atmospheric Administration 

INTRODUCTION 

It's a pleasure to be here in Portland at the fifth 

biennial Symposium on Mapping and Research in the 

Exclusive Economic Zone (EEZ) and to share the platform 

with my distinguished colleagues from the U.S. Geological 

Survey (USGS) and the Defense Mapping Agency (DMA). 

This is the first time I have attended an EEZ Symposium, 

and I am impressed by the number of attendees, the variety 

of organizations represented, and the quality of information 

both in presented papers and maps and in associated 

research results in the poster displays. I thank you for your 

efforts. 

I want to say at the outset of my remarks that the 

National Oceanic and Atmospheric Administration 

(NOAA) is committed to a strong national EEZ mapping 

program. We have a great deal of interest in the EEZ both 

in support of our own programs and also in support of the 

users of EEZ information. NOAA programs that directly 

benefit include the National Marine Fisheries Services 

assessment program, National Ocean Services Nautical 

Charting Program, and the work of our Environmental 

Research Laboratories. 

Activities external to NOAA that utilize the mapping 

data are from other Federal agencies (USGS, Minerals 

Management Service, Department of Defense, Environmental Protection Agency, National Science Foundation, 

and others), State agencies, private surveying companies, 

and numerous academic institutions. 

BACKGROUND ON NOAA 

NOAA has five main operating units: the Weather 

Service, Satellite Service, Fisheries Service, the Ocean 

Service, and the Office of Oceanic and Atmospheric 

Research (fig. 1). Some of these offices, such as the 

Weather and Satellite Services, have little direct interest in 

the EEZ program data. However, there are requirements 

from other sectors of NOAA for EEZ data, particularly off 

the West Coast and Alaska. These areas are of high value to 

the U.S. fisheries research communities. NOAA, along 

with many other researchers both within and without the 

government, has opened up a new field of scientific 

research with the discovery of sea-floor vent systems. 

NOAA's National Geophysical Data Center (NGDC) 

has been active in helping to develop and disseminate 

digital data products and holdings. In the National Ocean 

Service (NOS), mapping and charting has been our mainstay dating back to establishment of the Survey of the Coast 

in 1807. Programs within NOS include oceanographic 

research and observations, tide and current prediction, 

monitoring coastal environmental change, hazardous material response, management of our Nation's coastal zone, 

and a growing network of marine sanctuaries and estuarine 

reserves. 

THE EEZ MAPPING PROGRAM 

In 1984, we began an ambitious program to map the 

sea floor of the EEZ using high-resolution, multi beam sonar 

systems in conjunction with high-precision navigation. To 

date, we have surveyed 106,000 nmi2 (of the total 3.4 

million nmi2

) or roughly 3 percent of our EEZ. We have 

conducted surveys in the Gulf of Mexico, coastal California, Oregon, and Washington. We have also surveyed six 

map areas in Hawaii, two in Alaska, and a small area 

offshore Virginia on the East Coast. This amounts to about 

50 1:100,000 maps with 20-m contours each 0.5° latitude 

by 1 o longitude. As the symposium unfolds, you will hear 

much more detail about this work and in particular about the 

work off the West Coast. 

In May of 1991, we produced the first new threedimensional map of the Monterey, Calif., area at a scale of 

1:250,000. This map combines six smaller map sheets into 

one composite map. We are very proud of our mapmaking 

progress; since the fall of 1989, we have published 32 color 

1:100,000-scale maps and are distributing them through the 

distribution center in Riverdale, Md. We are also distributing a digital data set of 250-m gridded data for each map 

sheet. Our long··range plan is to make all our original swath 

sounding data available through the NGDC. We are utilizNOAA's EEZ Mapping Program-Challenges and Choices 9 
Figure 1. National Oceanic and Atmospheric Administration (NOAA) organizational chart depicting NOAA's five main 

operating units. 

ing funds reprogrammed from a special NOAA-wide Environmental System Data and Information Management program to assist us in reformatting and distributing the 

full-resolution digital data . 

We have accomplished a good deal of work in the 

EEZ over the past 7 yr; later on in the program you will hear 

details from Cmdr. Jerry Mills on some of the specific 

results of the mapping program. You will also be hearing 

from some of the individuals from organizations that are 

users of the data. 

10 Proceedings, 1991 EEZ Symposium on Mapping and Research 

We at NOAA, in cooperations with our associates at 

the USGS , are excited about the prospects for the future, 

including the prospect for improving our understanding of 

this rich and valuable natural resource area, the prospect for 

applying the knowledge we are gaining to support new and 

innovative research in the earth sciences, and the prospect 

for pushing out frontiers of new technology for exploring 

the deeper waters of the ocean. 

While NOAA management continues to have a strong 

interest in the EEZ Mapping Program, there seems to be 
more important ocean-related research in the agency that 

has higher priorities in regard to funding and available 

resources (especially ships to support the survey operations). This amounts to a dilemma that confronts Federal 

managers on a more frequent basis, which is the increasing 

high demand for products and services accompanied by a 

dwindling resource base. The solution to this dilemma 

requires innovative management techniques, cooperative 

resource sharing, and a commitment by users of the data to 

demand that the program be responsive. 

I want to make our interest in the program clear up 

front because, on the other hand, NOAA's EEZ program 

(and in particular the program in the Pacific) has taken a 

couple of hard shots recently in terms of budget and 

available ship time to support surveying. 

Despite our progress to date, we also have some 

failures, the foremost of which has been our inability to 

convince those within government who control the purse 

strings to accord this program the priority that we who are 

gathered here know and believe it should have. Clearly, in 

the budget process, ocean-floor mapping does not have high 

priority. 

Right now, we in the NOS are facing the prospect of 

a fairly bleak 1992-93. We do not have an active survey 

vessel on the West Coast, in Alaska, or Hawaii (and the 

prospect for correcting this situation is not clear). Our 

resources for continuing to print "hard copy" maps are 

literally drying up. Our goal for this year was to issue 20 

new maps, but right now we are looking at the prospect that 

there might be only 3 or 4, if that many. Even our ability to 

sustain a base program for data compilation and analysis is 

at risk. 

Why does this situation exist? I mentioned earlier that 

resources are the problem, but there are some more fundamental issues that need to be addressed. Let me share some 

of the questions I get and if they make you feel uncomfortable, so be it! 

1. Some say, if it's going to take more than 150 yr to 

complete the job, what is wrong with deferring the 

program another 1 or 2 or 3 yr? 

2. Some ask appropriately, why continue with the current 

mapping technology when the latest or newer systems 

are more productive .. .let's wait? 

3. Others query, who are the users anyway? I have to 

confess we hear about "interests" in the data, but around 

NOAA and at the Department of Commerce, I haven't 

seen anyone beating down the door. 

4. Finally, the real stumper: Where is the economic "payoff'? So far there hasn't been much, has there? However, the usefulness of EEZ data to oil and gas exploration in the gulf has shown real promise. 

These are all very difficult and complex questions we have 

been asked for years, but as yet they are unanswered! 

I'm going to be listening over the next 2 days trying 

to glean a better understanding of what this program is all 

about and how we might begin to resolve these questions 

and issues, and how we in NOAA can get things back on 

track. 

As U.S. Co-chair of the Pacific Congress on Marine 

Science and Technology, I have seen tremendous interest 

and opportunities for the United States to exert leadership. 

Personally, I have a great deal of interest in the 

Pacific, and I believe it holds one of the keys for future U.S. 

economic growth in the areas of marine science and 

technology. 

Dr. N arendra Saxena will be following after the break 

with a review of a fledgling Pacific mapping program at the 

University of Hawaii which Gary Hill and I have supported. 

We see this as an important step in the maturing of the 

national program. Cooperative ventures with academia and 

the private sector are important, and we should be doing 

more in this regard. 

In closing, I welcome your ideas and suggestions on 

how to keep the 10-yr plan a meaningful guide and what we 

might do to shore up NOAA's participation in the program. 

We are going to hang in there, but we do need your help. 

NOAA's EEZ Mapping Program-Challenges and Choices 11 
Mapping the Ocean Floor from the DMA-Defense 

Hydrographic Initiative Perspective 

Thomas E. Klocek 

Defense Mapping Agency 

The Defense Hydrographic Initiative (DHI) is the 

result of a number of initiatives both internal and external to 

Defense Mapping Agency (DMA). In the 1980's, DMA 

began a continuing modernization program that changed the 

way the Agency produced maps and charts. However, the 

products affected by this program focused on overland areas 

(for example, aeronautical and topographic products). This 

new program would allow DMA to utilize digital production methods to create mapping, charting, and geodesy 

(MC&G) products. Naturally, the Navy wanted nautical 

map and chart compilation to be accomplished with modem 

methods, but, for various reasons, this could not be done at 

the beginning of the modernization program. In the interim, 

DMA conducted an internal study of its hydrographic 

program and again came up with the need to take advantage 

of its new digital production developments in the creation of 

nautical products. The result is the DHI. 

The DHI is a coordinated, interagency group (DMA, 

National Oceanic and Atmospheric Administration, Navy) 

whose focus centers on areas of research and development, 

standardization, and production. This group is supported at 

the highest levels of the organizations, such as the Office of 

the Oceanographer of the Navy under the Chief of Naval 

Operations. 

Because DHI is a Defense program, its concentration 

is on the war-fighting needs of the armed services. Some of 

these requirements go beyond the basic need of navigation 

products: from nautical charting to acoustic performance 

prediction and surf prediction in support of systems such as 

the Tactical Environmental Support System. What is also 

evident from its charter and DHI participants is the concern 

for what is happening in the MC&G world as a whole and 

the key role that DMA plays as a major producer of MC&G 

data and products. 

A major objective of the DHI, the ultimate product, 

will be completion of the Master Seafloor Digital Data Base 

(MSDDB). Emerging Navy systems will need interoperable 

digital layers of ocean-bottom information to operate in 

Geographic Information System (GIS) processing environments. These layers include a gridded ocean-bottom terrain 

12 Proceedings, 1991 EEZ Symposium on Mapping and Research 

model and sea-floor characteristics that affect naval warfare, such as antisubmarine warfare, mine warfare, and 

amphibious assault. Data required to begin populating the 

MSDDB are resident principally at DMA, the Naval Oceanographic Office, the National Ocean Service, and the 

National Geophysical Data Center. DHI provides the forum 

for cooperation and joint development of necessary hydrographic and oceanographic data to begin working toward 

meeting the MSDDB requirement. 

In order to manage such an undertaking, an organization of four elements has been established. The functions 

of each group are discussed below. The Policy Steering 

Group (PSG) is chaired by DMA (Chief Scientist) and 

has representatives from DMA Headquarters, DMA 

Hydrographic-Topographic Center (HTC), Navy, and 

NOAA. The Technical Steering Group (TSG) is chaired by 

DMA Systems Center Systems Development Group and 

includes membership from the Navy staff, Navy labs, DMA 

offices, and other production and collection organizations 

within Navy, DMA, and NOAA. The TSG also exercises 

oversight of the working groups and subgroups that have 

specific tasks and goals on which to concentrate (such as the 

products working group, which has subgroups to address 

issues relating to individual products). 

Subgroups deal with specific issues and bring those 

issues to the working groups in one of three main areas, as 

appropriate. Issues are reviewed there, and information 

extracted for presentation to the next higher group, the 

TSG. The TSG will then provide direction and guidance 

and determine whether the issue needs a policy decision 

from the PSG. As mentioned before, the PSG is represented 

by such people as the Deputy Oceanographer of the Navy, 

the Director of Coast & Geodetic Survey, the DMA Chief 

Science Advisor, and the Commander, Naval Oceanography Command. 

As stated previously, one of the focal points of DHI 

is to establish standards. With the major objective of 

developing and populating a MSDDB, and the fact that a 

great deal of data will continue to be held at three organi-
zations, standards are crucial to the exchange of data among 

the organizations. 

In the area of data collection, these standards will 

address the actual data being collected (to ensure that the 

attributes required for data evaluation and postprocessing 

are captured), as well as data collection format. It is 

expected in the near future that near-realtime processing 

will take place onboard the collection platform to minimize 

additional preparation time before the data becomes a useful 

part of the data base. 

Of the standards areas under consideration, data 

evaluation is the most important and time critical. Our 

ability to automate the process of nautical chart production 

will hinge on how well we can evaluate, attribute, and 

control the data. Hydrographic Source and Assessment 

System (HYSAS) is the data management system whereby 

we will be able to track data both in its archived and in its 

processed forms and determine who needs what and where. 

Additional information on the development of the HYSAS 

will be given later in another presentation by Jim Moran. 

The final processed product will be a merger of the 

significant attributes and characteristics of the data within 

the system, using the best available data to fill all of the bins 

possible. 

The ultimate "product" is the MSDDB. This data 

base will be a layered GIS of geophysical and geoacoustical 

data. It will contain authoritative deconflicted sea-floor and 

subsea-floor information that is spatially attributed by 

point, grid, and vector formats. 

Mapping the Ocean Floor from the DMA-Defense Hydrographic Initiative Perspective 13 
Pacific Mapping Program 

Narendra K. Saxena 

Pacific Mapping Program 

College of Engineering 

University of Hawaii 

Abstract 

The Pacific Mapping Program is a unique program 

designed at the College of Engineering, University of 

Hawaii at Manoa, to conduct research, to provide service, 

and to offer other graduate education in ocean mapping. 

Research includes the integration of all types of available 

mapping data in the Exclusive Economic Zone of the 

Pacific Islands region (Hawaii, Guam, American Samoa, 

and Northern Marianas) and the development of new 

integration methods and data analysis techniques. Service 

includes the provision of needed mapping information for 

ocean resource assessment and evaluation in the Pacific 

Islands Exclusive Economic Zone, the education of personnel through specialized workshops on the islands, and 

the identification of areas where mapping is lacking and 

where mapping should be done. Graduate education 

includes a 1-yr Graduate Certificate Program in Marine 

Mapping, Charting, and Geodesy (presently in planning). 

This activity is unique because no university in the United 

States currently has an academic program in ocean mapping. The Pacific Mapping Program's objective is also to 

ensure that all mapping data of the U.S. Pacific Islands are 

located in one place. There will be a Regional Mapping 

Data Center that is within easy reach of all Pacific Islands. 

INTRODUCTION 

Discussions to establish a Pacific Mapping Program 

(PMP) started in 1985 with faculties of the Geography, and 

Geology and Geophysics departments. In 1987, the Hawaii 

Federal Congressional Delegation wrote to the President of 

the Pacific International Center for High Technology 

Research (PICHTR) asking the center to look at Exclusive 

Economic Zone (EEZ) needs of the American Flag Pacific 

Islands (AFPI). Based on this letter, discussions developed 

between the U.S. Geological Survey (USGS) and the 

National Ocean Survey (NOS). In January 1988, PICHTR 

awarded seed-money funding to initiate'1! PMP proposal. A 

proposal to establish a PMP at the College of Engineering in 

cooperation with the Hawaii Institute of Geophysics, 

14 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Department of Geography, Department of Geology and 

Geophysics, and Department of Oceanography was submitted to NOS and USGS through the National Sea Grant 

College Program. The dedication ceremony of the PMP (not 

the center) on March 15, 1990, was attended by representatives of USGS, NOS, Government of Japan, State of 

Hawaii, University of Hawaii, and the ocean industry. The 

first year's funding started from July 1, 1990. 

Assessment of EEZ resources requires comprehensive, accurate, and up-to-date bathymetric maps. Such 

maps are used for (NOAA, 1987): 

• Mineral exploration and development. 

• Deployment of research instrumentation on or near the 

sea floor, including submersible operation. 

• Fishing operations using deep trawl or bottom fishing 

gear. 

• Subsea pipeline or cable routing. 

• Geological hazard assessment. 

• Surveys of ocean waste-disposal sites. 

• Fish habitat research. 

A survey of accessible data of the Pacific Ocean 

indicates that little bathymetric information is available. 

Although the U.S. Pacific Islands EEZ (including the 

Hawaiian Islands) is approximately one-half the total EEZ 

of the United States, only 5 percent of the Pacific Island 

EEZ has been adequately mapped (Drummond, 1986). The 

report from the 1987 EEZ Symposium Island Mapping & 

Research Group (Lockwood and McGregor, 1988, p. 96) 

states: 

So little is known of the island EEZ that a rational and 

objective assessment of resources and geohazards is 

nearly impossible. The high potential for extensive 

strategic mineral deposits within U.S. sea-floor areas 

requires a thorough and widespread investigation. In 

order for the island nations to make intelligent decisions regarding use of their sea floor, they need 

sufficient technical information. 

Currently, maps are available for most Pacific 

islands. From the Defense Mapping Agency Hydrographic 

Center, individual maps of the Marshall Islands are available. However, such maps are of limited value to explora-
tion of EEZ resources because the fathom-sounding lines 

are quite far apart (0. 5° to 1 o longitude or latitude). Without 

sufficient density of data and with the artifacts that result 

from the contouring process, the shapes of bathymetric 

features are not accurate. 

The use of state-of-the-art laser, multi beam sonar, or 

sidescan sonars can produce a high density of depth 

soundings that can be used to develop the maps required for 

more detailed studies. 

Improved mapping of ocean-bottom morphology and 

sediment type and availability of such maps would almost 

immediately contribute to improved fisheries resource management. For example, the potential number of living 

resources at seamounts has only been superficially assessed 

because sampling is difficult and often the fine-scale 

topography of shallow portions is unknown (Boehlert, 

1986). Regions of upwelling that stimulate productivity and 

tend to attract higher order predators-both migratory and 

benthic fish- are hard to predict. A better understanding of 

morphology through bathymetric mapping and sea-surface 

temperature from remote sensing may eventually help to 

predict the presence of areas of upwelling. Benthic fisheries 

would benefit from improved bathymetric charts in targeting depths and for increasing precision in relocating fishing 

sites. 

Near-term benefits.-In the U.S. Pacific Island EEZ, 

ferromanganese crusts command current attention as a 

potential domestic source of cobalt. However, a great deal 

of additional work is needed to determine if the cobalt-rich 

manganese crusts are minable (Chave and Green, 1986). 

Continuous updating of bathymetric maps by use of stateof-the-art technology, such as that described above, will be 

needed for geological assessment of permissive areas and 

for the topographic precision that accurate assessment of 

mining sites demands. 

Longer term benefits.-Improved mapping may lead 

to other benefits, such as: 

1. Improved forecasting of tsunamis. Our prediction capability of tsunamis that are generated in the Aleutian 

Islands and other areas such as the South Pacific requires 

improved bathymetry. 

2. Determination of areas of sea-floor instability. Better 

knowledge of the ocean bottom is needed before seafloor cable routes and sites for Ocean Thermal Energy 

Conversion plant installations can be determined. 

Appropriate sites can be identified by documenting 

sea-floor characteristics (sediment type, evidence of 

deposition and (or) resuspension, turbidity currents, and 

mineral composition) and by determining current flow 

and topography. Optimally, sites selected should be 

areas that will not be used for other purposes such as 

mining. 

3. Determination of areas of slope stability. Sea-floor 

mapping and seismic reflection studies around islands of 

the Pacific indicate that large segments of the islands 

have collapsed to the sea floor. Massive submarine 

landslides have been observed in the waters around 

Hawaii, Guam, Johnston Island, and Samoa. The frequency and hazard associated with the slope instability 

are unknown. Sidescan sonar and acoustic mapping of 

slopes of inhabited islands would provide a measure of 

the natural hazards associated with marine development. 

GOALS 

If the Nation's interest in the Pacific Island EEZ is to 

be effectively served, it is essential that the capability be 

developed to continuously incorporate new and more 

sophisticated data as they become available into bathymetric maps and to make this mapping information available to 

Federal and State agencies and to private interests capable 

of undertaking Pacific Island EEZ resource development. 

The overall goal of this project is the development of 

a PMP at the University of Hawaii that facilitates exploration and development of resources of the Pacific Island 

EEZ. The program houses a repository of Pacific Island 

EEZ regional information and data. This objective closely 

follows the recommendations of Workshop 5-Scientific 

Mapping and Research to Characterize the EEZ Islands 

(Lockwood and McGregor, 1988, p. 95). Specific goals 

include: 

• Development of a data-processing system for comprehensive electronic ocean mapping. 

• Establishment and building of an appropriate data base. 

• Identification and determination of additional mapping 

requirements for EEZ resource exploration and development. 

• Establishment of links with other Pacific island and 

Pacific rim nations with similar EEZ interests. 

Second-year objectives (January 1, 1991-December 

31, 1991) include the following: 

• Enhance and improve the data processing system. 

• Expand the data base to meet the needs for EEZ resource 

exploration and development. 

• Design appropriate service and training programs. 

• Continue efforts to develop links with other Pacific 

groups. 

ACCOMPLISHMENTS 

First-Year Objectives (June 1, 1990-December 

31, 1990) 

Development of a Data-Processing System for 

Comprehensive Electronic Ocean Mapping 

The overall hardware and software acquisition and 

configuration plan initially focused on developing an 

Pacific Mapping Program 15 
inhouse data-processing and integration capability that 

would take the best advantage of existing software applications and data formats. To accomplish this requires development of processing platforms and communications connectivity. 

Hardware.-Prior to June 1, 1990, the PMP had one 

25-MHz "386" personal computer (PC), a monochrome 

monitor, and a laser printer. During July 1990, Valerie 

Paskevich of the USGS installed a VAX 3200 workstation 

with over 2.04 GB hard disk space, two dumb terminals, a 

nine-track tape drive, a workstation monitor, a Mitsubishi 

Diamond Scan monitor, and a Grinnell Image Processing 

System. She loaded and configured the VMS operating 

system, "C" and Fortran compilers, and the Mini-Image 

Processing System (MIPS) application and demonstration 

files for the processing of SeaBeam and Geologic LOngRange Inclined Asdic (GLORIA) sidescan sonar images. 

By October, a NEC MultiSync four-dimensional 

high-resolution (1,028X768 pixels) monitor and Orchid 

VGA graphics card had been purchased for the "386" PC. 

This new hardware allows use of PC-MIPS. An LA 210 dot 

matrix printer was purchased for the VAX for the purpose 

of printing source code for programmer support. An HP 

PaintJ et color pen plotter was purchased and configured to 

work with the PC. A 4-megabyte (MB) LaserMaster Card 

supporting 800 X 800 dots per in ( dpi) printing resolution 

was purchased and installed in the PC. 

Software. -During November 1990, Valerie 

Paskevich returned to provide MIPS training for Dr. Li. She 

used Internet to install MAPGEN (Map Generator) from 

Woods Hole onto the HP 9000. Developed at USGS, 

MAPGEN is used for cartographic processing: the definition of map grids, projections, and coastlines. DISSPLA on 

the HP 9000 is also used. 

Establishment and Building of an Appropriate Data Base 

Data Collection.-With the installation of MIPS, 

USGS has provided images, SeaBeam gridded, and navigation data. 

Identification and Determination of Additional Mapping 

Requirements for EEZ Resource Exploration and 

Development 

Since the Pacific Island EEZ mapping deals mostly 

with deepwater mapping where two basic resources (minerals and fisheries) exist, discussions were held with mining, fisheries, and Department of Business and Economic 

Development (State of Hawaii) personnel. 

Establishment of Links with Other Pacific Island and Pacific 

Rim Nations with Similar EEZ Interests 

During PACON 90, an international conference of 

marine science and technology in the Pacific that took place 

16 Proceedings, 1991 EEZ Symposium on Mapping and Research 

in Tokyo, the Principal Investigator (PI) met with representatives from Japan, Korea, Taiwan, and Australia to initiate 

discussions on mutually advantageous ocean-mapping 

research projects. 

During a visit to James Cook University, Australia, 

for another program, the PI met with various scientists to 

discuss collaborative opportunities. 

Second-Year Objectives (January 1, 1991-

December 31, 1991) 

Enhance and Improve the Data Processing System 

Hardware. -Using matching funds, PMP' s processing platform was extended to a Sun SP ARC II GS UNIX 

workstation with 32 MB of RAM, a 150-MB tape drive and 

a 1-gigabyte (GB) external hard drive. PMP is now using a 

variety of public-domain image-processing packages, 

including the Geographical Resources Analysis Support 

System (GRASS), ImageTool, FBM, and MAPGEN on the 

Sun and has access to Civil Engineering's Sun SPARC II 

GX system, on which is loaded Aviator Terrain Library, an 

animation package that allows the simulation of "flying" 

through undersea geological formations. PMP acquired a 

PC compact disc, read-only memory (CD-ROM) reader and 

a color scanner to enhance data input capabilities. 

Software.-During August 1991, Joseph Coddington 

of the USGS upgraded the MIPS software and trained Dr. 

Li in the standard mosaicking procedures used at his office. 

The free public-domain packages GRASS, MAPGEN, and Gridder/Mapper have been collected from various agencies and loaded onto the new Sun system. Procurement of the commercial package ARC/INFO has been made 

possible by a grant from Sea Grant, and a site license for 

WaveFront, courtesy of the School of Ocean and Earth 

Science and Technology (SO EST), is pending. Imageprocessing software used on the PC includes Surfer, PC 

Paintbrush IV, and Mirusimage. 

Software development has included a user interface 

that incorporates the MIPS module, making access to these 

modules systematic and simpler. A utility has been developed that transforms image and gridded data formats 

between the Sun and VAX. (See also sections on data 

processing, image processing and output, and research.) 

Connectivity. -An RS-232 asynchronous communications link was established with the HP-9000 UNIX 

computer at the College of Engineering. This enables 

connection with Internet, a worldwide university-supported 

communications network, to establish computer communications with the USGS at Woods Hole. Using electronic 

mail, remote login, and file transfer utilities, PMP remains 

in constant contact with Woods Hole and is gradually 

extending this contact to other oceanographic sites. PMP 

has been transferring public-domain applications, data, and 
image files back and forth to USGS and other research 

centers. 

A small Ethernet local area network (LAN) is being 

developed that will eventually be networked with the HP 

9000. The Sun and both PC's now have TCP/IP capability 

and can exchange data at an optimal 10 Mb (megabits) per 

second. The LAN will enable the PC to back up files and 

share disk space on a UNIX server, will allow remote login, 

and will soon include the VAX to optimize data exchange 

capabilities among the processors. 

Research in data analysis methodology.-PMP is 

looking at the problem of sparse distribution of available 

known depth points on the sea floor and the distortion of 

sea-floor models caused by inadequate interpolation methods. 

New mathematical models that enable shape from 

shading techniques are being used in research and software 

development. This technique uses bathymetric and sidescan 

sonar data by generating a more detailed sea-floor model 

with the conversion of imposed reflectance characteristics 

in sonar images to depth information about the sea floor. 

Expand the Data Base to Meet the Needs for EEZ Resource 

Exploration and Development 

Data Collection. -PMP has acquired GLORIA, SeaBeam, and SeaMARC data from the USGS, NOAA, and 

the Hawaii Institute of Geophysics (Barbara Keating), 

respectively. For research efforts, raw bathymetric and 

sidescan field data are essential. 

GLORIA sidescan sonar images of Cook Seamount 

(about l 0 X 1°) and Monterey Canyon (about 4°X4°) have 

been provided by the USGS. NOAA has released SeaBeam 

data in the form of a 0.5°X 1 o 250-m gridded file, three 

gridded files of the area around Monterey Canyon, and six 

gridded files of the area of the Hawaiian EEZ. 

Data Processing. -Programs have been written to 

enable the PC to process and print MIPS images from the 

VAX. MIPS images can be downloaded from the VAX to 

the PC. A program has been developed to transform MIPS 

image format to PostScript format so that the images can be 

printed by the HP LaserJet printer with a maximum dimension of 8. 5 x 11 in and a resolution of 800 dpi. The image 

was printed on a Varityper monochrome 4200 B-P printer at 

the Department of Geography at 1,800 dpi resolution. 

DISSPLA complements MIPS and MAPGEN and 

displays contour lines and three-dimensional mesh surfaces. 

A program has been developed to use DISSPLA's Fortran 

library to display three-dimensional surfaces. This program 

displays contour lines on the surface of an x, y plane, 

changes view angles and distance between viewer and 

object, and displays profiles in the x or y direction. Some 

printing of MAPGEN and DISSPLA images has been done 

on the HP LaserJet, but there are hardware limitations that 

result in inadequate printing resolution. 

Image Processing and Output.-To test PMP's capabilities in data integration, a pilot study of Cook Seamount 

area (19.0°-19.5° ~·latitude, 157.0°-158.0° W. longitude) 

was conducted; GLORIA and SeaBeam data were successfully integrated, and 9 x 11 in maps were prepared. 

Due to high hardware maintenance expenses, the 

purchase of an electrostatic plotter is currently not possible. 

USGS at Woods Hole and the Department of Geography at 

the University of Hawaii have generously offered their 

resources. Using data provided by the USGS at Menlo Park, 

a 2° x 2° GLORIA sonar mosaic was developed and plotted 

at 400 dpi in large format (GLORIA atlas format) by 

electrostatic plotter at Woods Hole and plotted at 1 ,400 dpi 

in 11 x n in format by an Optronics plotter at the Department 

of Geography. 

Design Appropriate Service and Training Programs 

Instructional Activity. -A joint effort with four academic departments under three colleges or schools and a 

research institute has been authorized for the development 

of a Graduate Marine Mapping, Charting, and Geodesy 

Certificate Program. 

Workshops.-An Ocean Mapping Workshop at 

Oceans '91 has been co-hosted by NOAA and the PMP. 

Marine mapping researchers have been invited to discuss 

mapping data standards. 

Presentations. -Seminars were held in Taiwan and 

Korea on ocean mapping technology and the PMP's efforts. 

(see Pacific-wide contacts below.) 

Papers have been presented by PMP at Oceans '91 

and the Winter Annual Meeting of the American Society of 

Mechanical Engineers. 

Services. -The production of a 2° x 2° GLORIA 

sonar mosaic map for the USGS at Menlo Park heralds the 

potential for PMP to provide this service in the future. 

Continue Efforts to Develop Links with Other Pacific 

Groups 

State Contacts.-Representatives from the Western 

Pacific Regional Fishery Management Council attended the 

February 21, 1991, PMP Advisory Council Meeting to 

express their requirements and concerns, and a close working relationship has evolved with Ms. Kitty Simonds, 

WESTPAC's Executive Director. Dr. Michael Cruickshank 

of Hawaii Natural Energy Institute has been consulted 

regularly on mining interest. 

Pacific-wide Contacts.-Discussions for cooperative 

Pacific EEZ mapping efforts were held with governmental 

and university organizations of Guam, the Marianas, Japan, 

Australia, Taiwan, and CCOP/SOPAC (Fiji). The possibility of training technicians from Guam and SOP AC nations 

is being examined. 

In August 1991, the author presented seminars 

arranged by the National Science Council, Taiwan, and the 

Pacific Mapping Program 17 
ADMINISTRATION 

PACIFIC MAPPING PROGRAM 

Advisory Council 

I 

I 

I 

College of 

Engineering 

I 

--

I 

University of Hawaii 

Sea Grant College 

Program 

I 

School of Ocean and 

Earth Science and 

Technology 

I 

L 

Pacific Mapping 

- - Program 

N arendra Saxena 

Membership (Federal Agencies) 

National Oceanic and Atmospheric Administration (NOAA) 

National Ocean Service (NOS) 

National Marine Fisheries Service (NMFS) 

Office of Atmospheric Research (OAR) 

U.S. Geological Survey (USGS) 

Defense Mapping Agency (DMA) 

Figure 1. The Pacific Mapping Program administration and Federal Agency membership. 

Korea Ocean Research and Development Institute 

(KORDI), Korea, on the PMP. National Taiwan University 

is interested in a cooperative effort to map their EEZ. 

KORDI is interested in a cooperative effort in data processing, since they will have a fully equipped research vessel 

constructed by March 1992. 

Publications.-A 50-page booklet and a 1-page leaflet have been developed for the PMP. 

Several articles have been published in journals such 

as Marine Geodesy and The American Society of Mechanical Engineers Winter Annual Meeting Proceedings. 

PARTICIPATING AND SPONSORING 

AGENCIES AND ORGANIZATIONS 

Major State of Hawaii participants and sponsors of 

the PMP include (1) the University of Hawaii College of 

Engineering and SOEST/Sea Grant College Program and 

(2) the Department of Business and Economic Development, State of Hawaii. Major Federal participants and 

sponsors include the USGS and the NOS. 

The University of Hawaii will continue to supply 

matching resources in terms of money, facilities, and 

personnel to support the current proposal. SOEST will 

provide the technical expertise of two researchers 

acquainted with state-of-knowledge ocean survey data to 

interpret, translate, and assist in data conversion. Federal 

Agency sponsors will provide bathymetric EEZ data and 

18 Proceedings, 1991 EEZ Symposium on Mapping and Research 

support the acquisition of equipment (hardware and software). Technical assistance in data analysis and related 

software development will also be provided. 

Plans for 1993 and beyond call for expanded local, 

national, and international participation. 

ADMINISTRATION OF PMP 

The PMP is a cooperative effort among several 

components of the University of Hawaii and will draw upon 

the capabilities of the College of Engineering, School of 

Social Science, and SOEST (fig 1). The Deans of the 

College of Engineering and SOEST will coordinate closely 

with the University of Hawaii Sea Grant College Program 

Director to monitor program progress. An advisory committee from academia, industry, and Federal and State 

agencies has been established to ( 1) approve and modify 

PMP objectives, (2) provide guidance and direction to the 

program, (3) identify and consolidate mapping efforts in the 

Pacific Basin, and (4) make PMP a focal point for discussion and cooperation with industry, government agencies 

(domestic and foreign), and academia involved in ocean 

mapping. The PMP Advisory Council will meet once every 

year. 

Facilities 

The PMP is located at the University of Hawaii in 

Manoa; office space for the mapping program is provided 
by the College of Engineering. Aside from two office 

spaces, an additional 900 ft2 of space, adequate for five new 

offices, generously has been provided by the College of 

Engineering. Image processing facilities in the Department 

of Civil Engineering and cartographic facilities within the 

Department of Geography and PMP are being used for map 

design and construction. Support facilities and equipment 

for fieldwork and map reproduction will also be provided by 

various units of the University. 

REFERENCES CITED 

Boehlert, G. W., 1986, Productivity and population maintenance 

of seamount resources and future research directions: NOAA 

Technical Report NMFS 43: p. 95-101. 

Chave, K.E., and Green, W.J., 1986, Cobalt-A marine strategic 

mineral resource recently found in the Hawaiian Exclusive 

Economic Zone: Sea Grant Quarterly, University of Hawaii 

Sea Grant Program, v. 8, no. 2. 

Drummond, S.E, 1986, Nautical charting in the Pacific-A status 

report: Proceedings of PACON 86, p. OST5/1. 

Lockwood, Millington, and McGregor, B.A., eds., 1988, Proceedings of the 1987 Exclusive Economic Zone Symposium on 

Mapping and Research-Planning for the next 10 years: 

U.S. Geological Survey Circular 1018, 175 p. 

NOAA, 1987, Plan for mapping the seafloor of the United States 

Exclusive Economic Zone 1988-92: National Oceanic and 

Atmospheric Administration, Washington, D.C., p. 52. 

Saxena, N.K., ed., 1988, Marine Geodesy Journal Theme Issue: 

Hydrography, New York, Taylor & Francis, v. 12, no. 1. 

Pacific Mapping Program 19 
Ocean Mapping-A Canadian Perspective 

John E. Hughes Clarke, Larry A. Mayer, and David E. Wells 

University of New Brunswick 

Gerard Costello 

Department of Fisheries and Oceans 

Abstract 

With the world's longest coastline and the second 

largest continental shelf, Canada has acknowledged the 

need for developing a strategy for acquiring, handling, 

and disseminating high-volume ocean mapping data. 

To meet this need, Canada has embarked on several 

initiatives designed to bring together government, industry, and universities. Two examples of these initiatives are: 

• Establishing the Natural Sciences and Engineering 

Research Council Industrial Research Chair in Ocean 

Mapping at the University of New Brunswick and 

• Initiating a project the Canadian Ocean Mapping System, integrating multibeam sonars, robotic vehicles, 

and advanced data processing techniques. 

These programs are briefly described, and current 

ocean-mapping activities, related to these initiatives, are 

discussed. 

INTRODUCTION 

In 1987, the Government of Canada approved an 

outline of an Oceans Policy for Canada. Two approaches 

described in this policy included fostering vigorous oceanic 

industries and enhancing the scientific and technical knowledge of Canada's oceans and ocean resources. In response 

to these two approaches, an ocean-mapping plan was 

proposed that would foster oceanic industries and increase 

our knowledge of the oceans. 

Canada's large ocean territories include both shallowand deepwater regions. Utilization of seabed resources, 

however, has been, and is likely to continue to be, focused 

on the continental shelf. A key to the safe and successful 

utilization of these resources is the ability to quickly and 

accurately map both the context and contours of the sea 

floor. While the instrumentation capable of mapping large 

regions of the deep ocean floor have been in use for a 

number of years, the same instrumental concepts are limited 

to much narrower swaths on the continental shelf. Furthermore, the data resolution required in shallow water is much 

20 Proceedings, 1991 EEZ Symposium on Mapping and Research 

higher than in deepwater (wreck/mine recognition). There 

is, therefore, a requirement to collect and process more 

efficiently high volumes of seabed data that will be needed 

to take advantage of these shallow-ocean territories. 

Two Canadian initiatives are presented as models that 

illustrate the mechanism to achieve the goals outlined in the 

Ocean Policy for Canada. The first, the Canadian Ocean 

Mapping System (COMS), involves Federal assistance to 

develop innovative high-technology, ocean-survey tools in 

Canada. The second, the Natural Sciences and Engineering 

Research Council (NSERC) Industrial Research Chair in 

Ocean Mapping at the University of New Brunswick 

(UNB), is an attempt to stimulate government/industry/ 

academia interaction in the field of ocean mapping. 

THE CANADIAN OCEAN MAPPING SYSTEM 

Background 

The Oceans Policy for Canada (Department of Fisheries and Oceans (DFO), 1987) called for an Ocean Mapping Program. As a result, in 1988 DFO's Development 

Branch was established to implement Canada's Ocean 

Strategy. The Canadian Ocean Mapping System (COMS) 

was initiated as an effort to enhance private-sector expertise 

in ocean-mapping technology. 

Project Overview 

The COMS program specifically sets out to merge an 

autonomous underwater vehicle, the DOLPHIN (Deep 

Ocean Logging Platform with Hydrographic Instrumentation and Navigation) (Kerr and Dinn, 1985), with a shallowwater, multibeam sonar (the Simrad EM-100), and to tum 

the product into a viable leading-edge sea-floor mapping 

system. 

The first phase of the development of COMS 

involved four projects: 
- Geo-Resources Inc. 

St. John's, Newfoundland, Canada 

A unique and revolutionary 

cost effective system for 

conducting sea-floor mapping 

surveys. 

GPS SATEWTES 

Figure 1. Diagram illustrating the operational configuration of the Canadian Ocean Mapping System. Used with the 

permission of Geo-Resources Inc. 

• DOLPHIN/EM-100 integration carried out by ISE 

Research of Vancouver, British Columbia, and SIMRAD 

Mesotech of Vancouver, British Columbia. 

• DOLPHIN handling system carried out by Brooke 

Ocean Technology of Dartmouth, Nova Scotia. 

• Hydrographic data processing system development carried out by Ocean Mapping Group, University of New 

Brunswick, and Universal Systems Limited (USL) of 

Fredericton, New Brunswick. 

• Operational sea trials and overall system integration 

(including realtime differential Global Positioning System (GPS) carried out by Geo-Resources Inc., of St. 

Johns, Newfoundland. 

The DOLPHIN 

DOLPHIN is a 8,000 lb, 7-m-long diesel-powered 

torpedo (fig. 1), which is hydrodynamically stable and 

Ocean Mapping-A Canadian Perspective 21 
operated in the open ocean at speeds of up to 14 knots. Its 

development began in 1983 when it was conceived as a tool 

to replace manned hydrographic launches in open-sea work. 

Three DOLPHINS were delivered to the Canadian Hydrographic Service in 1985 and instrumented with a 15-kHz 

echosounder and Loran C receiver the following year. Field 

trials in 1988 demonstrated that it was a feasible platform 

for hydrographic work but specifically identified limitations 

in the launch and recovery system. In 1989, the COMS 

program was initiated. 

Progress 

At the current time, the DOLPHIN/EMlOO integration has been completed. In June 1991, DOLPHIN was 

equipped with video cameras, sidescan sonar and a sectorscanning sonar and used as part of an oceanographic "Wave 

Breaking Study." During November 1991, 2 weeks of sea 

trials were successfully completed off Eastern Canada. 

DOLPHIN and its mother ship, CSS Matthew, both 

equipped with EM100 multibeam sonars and realtime differential GPS positioning, completed the hydrographic 

survey of a test site. The bathymetric data sets were first 

"cleaned" by using UNB 's new Hydrographic Data Cleaning System (HDCS), and then hard copies such as threedimensional perspectives, field sheets, and contour maps 

were produced by using USL' s CARIS. This was accomplished onboard ship, shortly after the data were collected. 

In sea state 5 (35 knot gales and 3- to 4-m seas), the 

DOLPHINIEM100 proved to function much better than the 

Matthew/EMlOO. In these conditions, the Matthew/EMlOO 

experienced significant data loss, whereas the DOLPHIN/ 

EM 100, travelling beneath the waves, functioned well. 

There was no apparent acoustic interference between the 

two EM100 sonars when DOLPHIN and Matthew were 

staggered along track. Excellent line keeping was achieved 

with positioning accuracy of about 5 m using differential 

GPS and DOLPHIN under computer control. 

In January 1992, the offshore sea trial was undertaken 

to test the new dynamically compensated launch and recovery system. A complete commercialized system involving 

two DOLPHINs will be available in late 1992. 

Future Developments 

Now that COMS is in private hands, new applications 

are being pursued. These include instrumenting DOLPHIN 

for acoustic fish stock assessment, geophysical data acquisition, and mine counter measures. The most significant 

development planned for COMS is the upgrading of the 

EMlOO sonar to the new EM1000 multibeam sonar, which 

includes both a wider bathymetric swath and sidescan 

imaging capability. This will require enhanced data-use 

software to process correspondingly greater volumes of 

image data acquired. 

22 Proceedings, 1991 EEZ Symposium on Mapping and Research 

THE NATURAL SCIENCES AND ENGINEERING 

RESEARCH COUNCIL (NSERC) INDUSTRIAL 

RESEARCH CHAIR IN OCEAN MAPPING 

Background 

In response to a perceived bottleneck in shallowwater swath data processing (in particular, data cleaning to 

meet the needs of national hydrographic organizations), the 

Ocean Mapping Group was set up in 1988 at the University 

of New Brunswick. The mandate of the group was to 

develop innovative methods for the management, processing, depiction, and interpretation of ocean mapping data. 

The group is comprised of members of the Surveying 

Engineering Department and the Faculty of Computer 

Science with particular expertise in geodesy, hydrography, 

spatial data structures, digital mapping, and visualization. 

The Ocean Mapping Group applied for funding to the 

Natural Sciences and Engineering Research Council of 

Canada (NSERC) under their Strategic Grants program. 

NSERC funds much of the research in science and engineering at Canadian Universities under several programs, 

including Strategic Grants (in a few selected areas of 

strategic importance, of which Oceans is one) and University Industry Cooperation Program. The Ocean Mapping 

Group Strategic Grant application in hydrographic data 

cleaning was successful. It specifically addressed the problem of high volume bathymetric data sets. A firstgeneration hydrographic data cleaning tool, geared toward 

shallow-water multitransducer or multibeam sounders, was 

developed in 1989. This product was commercialized by 

Universal Systems Limited and has been sold to Krupp 

Atlas and Holming. A second generation of this tool, 

integrating improved algorithms and adhering to strict 

programming standards (Unix/X/Motif), was developed and 

commercialized in 1991 and has just been tested by the 

Canadian Hydrographic Service by using Simrad EM-100 

sounders. This tool is a significant part of the COMS 

program, described above. 

The Industrial Research Chair 

In order to extend the diversity of the Ocean Mapping 

Group, an NSERC Industrial Research Chair in Ocean 

Mapping was proposed and awarded in 1990. This chair is 

funded jointly by NSERC and a series of Industrial Partners 

including: 

• Petro-Canada 

• Universal Systems Limited 

• Department of Fisheries and Oceans 

• Atlantic Canada Opportunities Agency 

The chair is funded over a 5-yr period, and the 

NSERC portion is renewable for another 5 yr. Through the 

addition of the chair, expertise in marine geology and 

geophysics was added to the group with a corresponding 
Ml =~JJI'sw?JK Ocean Mapping Group 

NSERC Chair in Ocean Mapping 

• OCEAN MAPPING : A CANADIAN PERSPECTIVE 

Hydrographic Ground Truthing 

Acoustic Measurements: 

- EM-1 00/1 000 

- Navitronics 

- Vertical Beam Sounder 

- Browser Altimeter 

- Sidescan Sonar 

- Chirp Profiler 

Bay of Fundy Option 

Ground Truth: 

- Browser Stereo Photos 

- Aerial Stereo Photos 

- Topographic Survey 

- Sediment Physical Properties 

- Placement of Geometric Forms 

- Physical Oceanography 

Figure 2. Conceptual diagram outlining the measurements that will be taken as part of the Hydrographic 

Ground-Truthing Program. Used with the permission of the University of New Brunswick, Ocean 

Mapping Group. 

increase in funding base. The Group now is able to expand 

studies from strictly marine topographic data to include 

substrate classification by using remote acoustic methods. 

Current Research Initiatives 

Most recently, a second strategic grant has been 

proposed and awarded addressing the question of hydrographic ground truthing. The issues raised are the spatial 

transfer function (the relation between the true topography 

and that represented by the remote imaging system) and the 

degree to which substrate classification can be extracted 

from acoustic imaging systems. 

Rigorous ground truthing of remote acoustic-swath 

systems has not been attempted previously. Intercomparisons of different swath systems have been attempted (Gutberlet and Schenke, 1989), and approaches have been made 

to understanding the acoustic interaction of particular swath 

systems with the sea floor (Gardner and others, 1991). But 

these have focused on deep water where no truly independent measure of depth may be obtained (short of a lead line), 

and acoustic footprints are much larger than sampling size 

(corers or bottom cameras). The Ocean Mapping Group 

Hydrographic Ground-Truthing Program will focus on shallow water (fig. 2) where independent measurements at a 

scale comparable to the acoustic footprint may be realistically made. 

Ocean Mapping-A Canadian Perspective 23 
71 25" .................................... 

................................. 

. . . . . . . . . .. . .. . .. .. .. . .. . . . . . . . . . . .. . . .. . . . . .. . .. . . . . . . . . .. . .. . .. . . . .. . .. .. . . . . . . . . .. . . .. . . . . . . . . .. . . .. . .. . . . . . . . . .. . .. . . . . .. .. . . . . . . 

Hopets 

35 

: :: ITill Sand 

: : : l::ll Gravelly sand 

: : : WW Silty sand 

: : : ~ Sandy silt 

: : : ~ Clayey silt 

: : : Hm Sand slit clay 

: : : 0 UndetermIned • • • <Thtn layer sedtm~nt 

over rocttl 

41:::::::::::::::::: m 

30"------- ••••••••••• 

71 25" 

[I] 

I ........ . . . .. . . . -... .. 

f. ::::~···· •••• ro ..... ·- ••••• en 

...... "-' 

§I IIll ..••.. :J 

M ·······~ ·······c ••••••• ro ....... c ········0 

........ u 

35 

41 

30" 

Figure 3. Comparison of Chirp Sonar and core results. Chirp sonar 

survey of Narragansett Bay, R.I. Line down the middle of the bay 

represents the chirp sonar profile. Sediment classification based on 

chirp sonar returns is coded onto this line. Numbers in circles indicate 

areas where additional ground truth data were obtained. Coded 

squares represent descriptions of cores from the literature (from 

leBlanc and others, 1992). Used with the permission of the journal of 

the Acoustical Society of America. 

Other current research projects underway within the 

Ocean Mapping Group include quantitative high-resolution 

vertical incidence acoustic profiling and sediment classification. 

High-resolution seismic profiling has long been used 

as a tool for defining structural relations in the upper 100 m 

of the seabed and for qualitatively estimating sediment type 

by the identification of "echo-character." Recent advances 

in sonar and signal-processing technology, however, have 

led to the development of a new high-resolution profiling 

24 Proceedings, 1991 EEZ Symposium on Mapping and Research 

system that has the potential for providing quantitative 

information about sea-floor and subsurface-sediment properties (Mayer and LeBlanc, 1983). The system uses a long, 

2- to 12-kHz swept FM pulse to provide the bandwidth and 

energy output necessary for high resolution with substantial 

subbottom penetration. Because of the long pulse, the 

returned echoes must be processed to achieved the resolution predicted by the bandwidth. This processing involves 

matched filter correlation (to compress the long chirp into a 

spike) and correction for amplitude degrading factors like 
Figure 4. A co-registered image of a 60X60 km 

region of the continental margin off the northern 

great Barrier Reef. Landsat MSS (Band 4) data of 

the coastline and continental shelf are geographically located with respect to Geologic LOngRange Inclined Asdic (GLORIA) sidescan sonar 

spherical spreading loss and sediment attenuation . The 

resulting subbottom profile is a quantitative image of 

subsurface structure that can provide the basis for statistical 

studies of the physical properties of marine sediments 

(Schock, LeBlanc, and Mayer, 1989). Tests of this system 

in Narragansett Bay have revealed that analysis of the 

amplitude of the sea-floor return can provide a robust means 

for identifying sediment type (fig. 3; LeBlanc and others, 

1992). 

imagery of the floor of the adjacent continental 

slope and Townsville Trough. The intertidal and 

subtidal reefs are visible as light features on the 

continental shelf. The canyons, cut into the adjacent continental slope, stand out as light features 

within the GLORIA data. 

Integration of Airborne and Spaceborne Data Sets with 

Acoustic Imagery 

Work has been carried out integrating Landsat MSS 

imagery of shelf carbonate environments with acoustic 

imagery of continental slope-drainage patterns (fig. 4). This 

technique provides a method for examining spatial relations 

between shelf and coastal morphology and deepwater 

topography. Extensions of this process suggest that physical 

oceanography revealed in sea surface color imagery can, in 

Ocean Mapping-A Canadian Perspective 25 
Figure SA. Three-dimensional graphical interface showing the flight path predictor (rectangular box with tails) 

over a decimated topographic grid. This allows the user to move rapidly within the three-dimensional space 

and position the view with respect to objects of interest. 

some cases, usefully indicate submerged topography. In 

conjunction with the hydrographic ground-truthing program, the integration of stereo airborne photography (and 

derived topography) of coastal intertidal regions and corresponding sonar imagery and topography will be attempted. 

Quantitative Measurements of Sea-Floor Backscatter 

Strength as a Means of Empirical Sediment Classification 

Using the new generation of topographically constrained imaging systems such as the Simrad EMlOOO 

system, there is the potential to use the image data as a 

means of remote sediment classification. While theoretical 

modeling of oblique acoustic interaction with the seabed is 

limited, by combining quantitative imagery and the dense 

sediment-sampling data sets already existing on the shelf, 

empirical correlations may be developed. 

26 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Extension of Current Hydrographic Data Cleaning Software 

Products to Handle Simultaneous Sidescan Imagery as an 

Aid in Error Detection 

Shallow-water acoustic systems operating at frequencies of 100-200 kHz are far more prone to interference from 

midwater returns (bubbles, fish, kelp, and so forth) than 

their deepwater counterparts operating at frequencies 

around 12 kHz . Considerable ambiguity exists when 

attempting to recognize a false sounding based on statistical 

methods (Ware and others, 1991). With the extension of the 

shallow-water swath systems to provide complementary 

backscatter amplitudes, the operator should be able to use 

the imagery to identify whether an outlying series of 

soundings may be an artifact or a real feature (wreck or 

glacial erratic). Such decisions allow greater confidence to 

be placed on soundings but are hard to implement remotely 

(using automatic techniques). Therefore, simultaneous 
Figure 58. Full resolution image of a digital terrain model (in this case a 1,000x1,000 grid of the North 

Atlantic), which is created at any time-approximately 5 seconds after the flight path (defined by the 

predictor) is interrupted . 

access to the geographic distribution of soundings and 

imagery will be required. Upgrading the existing hydrographic data cleaning software to use amplitude information 

is planned. 

Combining Multiparameter Data Sets and ThreeDimensional Visualization 

Using sidescan imagery to increase confidence in 

soundings, as described above , is only one application of 

multiparameter data sets. The same data pair (topography 

and texture) can be combined to reveal subtle relations 

between sediment distribution and topography and thus 

provide insights into sea-floor sedimentary processes. 

While static three-dimensional representations provide increased insights, three-dimensional tools are optimal 

only when the operator can freely move about the domain to 

perceive the same data set from different perspectives. 

Tools allowing rapid mobility over data sets have been 

developed (fig . 5; Chapman and Ware, 1992). These tools 

are intended to form a user interface into data sets whether 

for data cleaning or data interpretation purposes. 

Spatial Data Structure and Data Bases 

Current processor speeds limit the size of threedimensional data sets that can be viewed dynamically (in 

realtime). To get around this limitation, a dynamic data 

structure for gaze-directed viewing of high-density univariate maps has been developed. The data structure has 

maximum triangle resolution where the view vector intersects the data, with progressively larger triangles as one 

progresses away from this point. Using a Silicon Graphics 

IRIS 4D/85GT, a 650 by 800 uniformly spaced data set may 

be viewed at 18Hz. A similar size but nonuniformly spaced 

data set can by viewed at 5 Hz. 

As part of the HDCS needs, an investigation of the 

use of relational data bases for storing large amounts of 

spatially indexed bathymetry is underway. A set of C 

Ocean Mapping-A Canadian Perspective 27 
functions for creating, updating, and searching a Morton 

code index of bathymetric "profiles" (multibeam swaths) 

has been developed. These functions return a list of profiles 

inside any arbitrarily oriented rectangular window. The data 

is assumed to be stored in the HDCS structure (Ocean 

Mapping Group, 1991). Initial results show that this direct 

spatial search of 90 megabytes of data (representing approximately 74,000 profiles) takes between 0.5 and 2.5 seconds 

on a SUN 4/150. 

SUMMARY 

Canada has only recently begun to implement its 

ocean strategy. Priorities have been set that focus on 

economic potential and environmental conservation of Canada's oceans and ocean resources. Implementation of this 

ocean strategy depends strongly on the capability of combined government/industry/ academia interaction. 

The Canadian Ocean Mapping System and the 

NSERC Industrial Research Chair in Ocean Mapping are 

only a part of this strategy; they represent a model for 

achieving the goals set out in the Oceans Policy for Canada. 

REFERENCES 

Chapman, D., and Ware, C., 1992, Manipulating the future: 

Predictor based feedback for velocity control in virtual 

environment navigation: Symposium on Interactive 3D 

Graphics, Cambridge, Mass., April, 4 p. 

28 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Department of Fisheries and Oceans, 1987, Oceans Policy for 

Canada: A strategy to meet the challenges and opportunities 

on the oceans frontier: Communications Directorate, Department of Fisheries and Oceans, Ottawa, document DF0/4178. 

Gardner, J.V., Field, M.E., Lee, H., and Edwards, B.E., 1991, 

Ground-truthing 6.5 kHz side scan sonographs: What are we 

really imaging?: Journal of Geophysical Research, v. 96, p. 

5955-5974. 

Gutberlet, M., and Schenke, H.W., 1989, HYDROSWEEP: New 

era in high precision bathymetric surveying in deep and 

shallow water: Marine Geodesy, v. 13, p. 1-23. 

Kerr, A.J., and Dinn, D.F., 1985, The use of robots in hydrography: International Hydrographic Review, v. LXII, p. 41-

52. 

LeBlanc, L.R., Mayer, L.A., Rufino, M., and Schock, S., 1992, 

Marine sediment classification using the chirp sonar, Journal 

of the Acoustical Society of America, v. 91, no. 1, p. 

107-115. 

Mayer, L.A., and LeBlanc, L.R., 1983, The chirp sonar-A new 

quantitative high-resolution profiling system, in Pace, N.G., 

ed., Acoustics and the Seabed: Bath University Press. 

Ocean Mapping Group, 1991, Hydrographic data cleaning system 

HDCS B. 5 data structure design: Working document of the 

UNB Ocean Mapping Group, Fredericton, N.B., 41 p. 

Schock, S., LeBlanc, L.R., and Mayer, L.A., 1989, Sediment 

property determinations using a wide-band, frequencymodulated sonar system: Geophysics, v. 54, n. 4, p. 

445-450. 

Ware, C., Knight, W., and Wells, D., 1991, Memory intensive 

statistical algorithms for multibeam bathymetric data: Computers and Geoscience, v. 17, no. 7, p. 985-994. 
Cenozoic Geologic History of the Oregon 

and Washington Continental Margin 

Parke D. Snavely, Jr. 

U.S. Geological Survey 

INTRODUCTION 

The Cenozoic tectonic history of the Oregon and 

Washington continental margin (OWCM) was molded by 

underthrusting, transcurrent faulting, and extension during 

oblique convergence between North America and oceanic 

plates to the west. Sedimentation, punctuated by episodes 

of volcanism, was essentially continuous in the forearc 

basin whose trough lay along the present Inner Continental 

Shelf and extended northward from the Klamath Mountains 

970 km to Vancouver Island (fig. 1). 

A prerequisite to an understanding of the Cenozoic 

evolution of the Pacific Northwest Exclusive Economic 

Zone (EEZ) and the relation of this history to potential 

mineral resources and geohazards is the seaward extension 

of the structural and stratigraphic framework of western 

Oregon and Washington. A thorough understanding of the 

onshore geology established by classical detailed mapping 

permits a more rigorous interpretation of the geophysical 

data collected at sea. Also, integration of the onshore and 

offshore data measurably improves our understanding 

of Cenozoic evolution of this active continental margin 

(Snavely and Wells, 1991). 

GEOLOGIC FRAMEWORK 

Paleocene to Middle Miocene 

The oldest rocks in the Oregon-Washington Coast 

Ranges and the Olympic Peninsula are Paleocene and lower 

Eocene oceanic basalt that were locally developed as islands 

and seamounts. These basalts most likely formed by in situ 

eruptions (62-56 Ma) during oblique rifting and extension 

of the continental margin (fig. 2), as evidenced by locally 

interbedded terrestrial sediments and felsic volcanic breccias. On the Olympic Peninsula, lower Eocene coccolith 

limestone interbedded with pillow lava and basalt breccia 

indicates a deep-ocean depositional environment. However, 

in the Oregon Coast Range, Paleocene and lower Eocene 

microfossils in basaltic siltstone interbeds in pillow lavas 

30 Proceedings, 1991 EEZ Symposium on Mapping and Research 

indicate a shallower water depositional environment. A 

thick lower Eocene siltstone and middle Eocene turbidite 

sandstone sequence buried the islands while the rift basin 

was subsiding. The middle Eocene turbidite strata overlap 

both oceanic basalt and pre-Tertiary rocks of the Klamath 

Mountains, establishing that suturing of the Coast RangeOlympic terrane to North America occurred at about 50 Ma. 

Continued high rates of moderately oblique convergence 

caused strike-slip faulting and tectonic rotations along the 

continental margin. The north-trending Fulmar fault on the 

Oregon shelf (fig. 1), which juxtaposes lower Eocene 

graywacke on the west against lower Eocene oceanic crust 

of the Coast Range, is interpreted as a right-lateral fault 

with a minimum offset of 200 km. The fault is marked by 

a steep magnetic gradient, and as much as 2,200 m of lower 

Eocene sandstone of the Fulmar terrane was penetrated in 

two wells drilled west of the gradient. Two wells drilled 

east of the magnetic gradient encountered lower Eocene 

Siletz River Volcanics, which represent oceanic crust. 

Following accretion of the Coast Range terrane, plate 

models indicate a marked reduction in the convergence rates 

between the Pacific and North American plates beginning 

about 43 Ma. This period correlates with renewed extension 

and rifting of the Coast Range forearc basin that produced 

major episodes of middle and late Eocene alkalic basalt 

volcanism, early Oligocene nepheline syenite and camptonite sills and dikes, and extensive late Oligocene ferrogabbro 

sills. Concomitant with these extensional igneous events in 

the Oregon and Washington Coast Ranges, episodic periods 

of north-south transpression occurred in the northern part of 

Figure 1. Generalized onshore geologic map of west- ~ 

ern Oregon and Washington and southern Vancouver 

Island, B.C., with inferred locations of major faults on 

the continental shelf. Offshore faults concealed by 

younger strata are indicated by short dashed lines. LRF, 

Leech River fault; SJF, San juan fault. Outcrops of 

middle Miocene basalt not shown in Willamette Valley; 

upper middle Eocene volcanics not shown in the eastern part of Puget Sound. 
Commercial Seabed Surveys in the U.S. EEZ and Issues 

Associated with the Distribution of These Data 

Donald M. Hussong 

Seafloor Surveys International 

Abstract 

Seafloor Surveys International has conducted anumber of high-resolution side-scan sonar and swath bathymetry surveys for communications and power cables as well 

as fisheries evaluation within the U.S. Exclusive Economic 

Zone. Over 3,500 km2 of high-resolution data have been 

collected, with 100 percent bathymetry coverage that is 

typically contoured at a 5-m interval to 1,000-m depth, and 

at a 50-m contour interval in deeper areas. These data are 

acquired and routinely processed into publication-quality 

charts following International Hydrographic Organization 

standards, at a commercially attractive cost. Routine mapping by commercial surveyors may provide an effective 

method to meet some national government survey objectives. 

The handling of digital swath-mapping data is presently too cumbersome to promote responsible distribution of these data. An appropriately funded program 

should be established to standardize formats and promote 

distribution of these valuable data. 

Commercial Seabed Surveys in the U.S. EEZ and Issues Associated with the Distribution of These Data 29 
\ 

0 

0 

"' >

~ 

~ Cenozoic Cascade arc volcanic 

~ rocks, undifferentiated 

~ Middle Miocene basalt flows 

~and sills 

Middle Miocene to Upper 

~ ~r~{~~ef:r:~~~~~ge and ~ Eocene and melange broken 

lll!/£li1 formation 

D ~e~f; ~~~a~iddle Eocene 

~ Middle Eocene turbidite 

L:i:J sandstone 

~ Lower_ Eocene and Paleocene 

t::.:.:.::l oceaniC basalts 

~ ~~ed~~~~z~;~~ks, 

Inferred limits of Miocene and ,.,. ,._Oiiocene melange 

Faults, dashed where ~-concealed. Arrows show strikeslip displacement 

J-& Thrust faults 

7 -¢" Offshore exploration wells 

... 

... 

Cenozoic Geologic History of the Oregon and Washington Continental Margin 31 
KULA I 

\ ~\ \ ~Al'J \ 

/,FAR 

\ 

\ 

Figure 2. Diagram showing inferred continental margin 

rifting model for the origin of the Paleocene and lower 

Eocene oceanic basalt (x pattern) and oceanic islands 

(circular areas) in western Oregon and Washington. K, 

Klamath Mountains; V, Vancouver Island, B.C.; FAR, 

Farallon plate; KULA, Kula plate; NAM, North American 

plate; F, Fulmar fault. Arrows denote direction of movement of the Kula plate relative to the North American 

plate. 

the Olympic Peninsula and in the Strait of Juan de Fuca. 

Imbricate thrust sheets, compressional folds, north-trending 

clastic dikes, and debris flows derived from an uplifted 

Vancouver Island terrane are interpreted as resulting from 

the buttress effect of the Vancouver Island thick continental 

crustal block against a northward-moving Olympic terrane. 

This period of intermittent northward translation of 

the Olympic terrane was interrupted by two major periods 

of nearly head-on convergence that are recorded by thick 

32 Proceedings, 1991 EEZ Symposium on Mapping and Research 

accretionary melange wedges formed during the late Eocene 

and late middle Miocene. These broken formations and 

melanges are exposed only on the Olympic Peninsula but 

are present on the Washington continental shelf and on the 

outer shelf and slope of Oregon. 

Deposition of Oligocene tuffaceous marine strata in 

the forearc region signaled the beginning of voluminous 

Cascade arc volcanism at about 35 Ma and contemporaneous subsidence of the forearc. Although rift volcanism 

characterized the forearc during the late Eocene and early 

Oligocene in the Oregon and Washington Coast Ranges, 

there is evidence for late Eocene underthrusting in the 

Olympic Mountains accretionary wedge. Along the north 

flank of the Olympic Mountains more than 6 km of Eocene 

and Oligocene sediments were deposited in a deep marginal 

basin whose trough lay along the Strait of Juan de Fuca. 

Some of the turbidite sands and silts deposited in this basin 

had a source area 200 km to the northwest near Nootka 

Sound on the south side of Vancouver Island. Debris flows, 

submarine landslides, and conglomerate eroded from the 

uplifted Vancouver Island terrane are interbedded with 

Eocene and Oligocene bathyal strata of the marginal basin. 

Regional uplift in the forearc basin in the early 

Miocene restricted marine deposition to the west flank of 

the Oregon Coast Range and the adjacent continental shelf 

and to the Coos Bay, Newport, Astoria, Grays Harbor, and 

Tofino-Fuca structural embayments (fig. 1). On the continental shelf thick deposits of lower Miocene mudstone are 

widespread and form the matrix of the accretionary melange 

wedges and the overpressured cores of diapirs. Nearshore 

deltaic and strandline sandstone and siltstone deposits of 

middle Miocene age grade westward into predominantly 

bathyal siltstone in the deep marginal basin off Oregon. 

Along the central Oregon coast, two tholeiitic basalt 

units are interbedded with middle Miocene sandstone and 

siltstone. The older basalt is petrochemically identical to the 

Grande Ronde Basalt of the Columbia River Basalt Group, 

and the younger basalt is petrochemically identical to the 

Frenchman Springs Member of the Wanapum Basalt of the 

Columbia River Basalt Group. Sills and flows of the older 

unit are widespread in the northern Oregon Coast Range and 

on the continental shelf and were penetrated in several of 

the test wells. The younger basalt, however, is restricted to 

the inner shelf. 

A major episode of transpression occurred in western 

Oregon and Washington and on the adjacent continental 

shelf in the late middle Miocene as indicated by a regional 

unconformity on the continental shelf and strongly 

deformed middle Miocene strata in the Coast Ranges. Uplift 

of the Coast Range-Olympic Mountains formed highland 

areas that were rapidly eroded and supplied large amounts 

of clastic debris to elongate basins on the continental shelf. 

On the Oregon inner shelf, strata as young as middle 

Miocene were folded and uplifted, truncated by erosion, 

and subsequently downwarped and overlapped unconform-
ably by upper Miocene strata. Uplift was greatest on the 

Olympic Peninsula, perhaps partly owing to isostatic uplift 

of the thick prism of melange and broken formation that was 

subducted during the late middle Miocene and partly owing 

to northward motion of the Coast Range terrane. 

Late Miocene and Pliocene 

In the late Miocene and Pliocene, episodic downwarping of a deep marginal basin on the shelf off Oregon 

was virtually continuous, and more that 2,000 m of sand 

and silt were deposited. Upper Miocene and Pliocene 

deposits thinned against the eastern border of the marginal 

basin and against older outer shelf structural highs. On the 

outer shelf, basins formed landward of folded and thrustfaulted upper Oligocene to upper middle Miocene melange 

welts. On the central and southern Washington shelf, as 

much as 2 km of upper Miocene and Pliocene sediment 

accumulated on a thick accretionary wedge of melange and 

broken formation of late Oligocene(?) to late middle Miocene age. The Miocene and Pliocene strata also thin against 

growing anticlines or diapirs, the cores of which consist of 

upper Oligocene to middle Miocene melange and broken 

formation. Adjacent to these diapiric structures numerous 

unconformities, growth faults, and gravity slides occur 

within younger strata, all of which likely reflect episodic 

uplift . 

OFFSHORE STRUCTURE 

Seismic-reflection profiles across the deformational 

front along the continental slope of Oregon and Washington 

show that episodic underthrusting of the Juan de Fuca plate 

beneath the North American plate has produced a family of 

north- to north-northwest-trending elongate, en echelon anticlinal ridges bounded by thrust faults. These folded ridges 

uplift Pleistocene abyssal sediments as much as 1, 100 m 

and are bathymetrically well defined. These fault-bounded 

folds are well imaged on seismic profiles across the deformation front along the continental slope. In Oregon, the dip 

of these thrusts is eastward, whereas along the Washington 

slope the dip is westward. The change in the direction of 

vergence occurs north of the Columbia River. 

Generalized cross section (fig. 3) is interpreted from 

a multichannel seismic-reflection profile provided by the 

Exxon Company, U.S.A. This profile extends westward 

from the inner shelf just south of the Columbia River to the 

abyssal plain. The profile crosses the deformation front on 

the continental slope and images a fold-thrust belt of 

uplifted Pliocene and Pleistocene abyssal strata formed by 

the underplating of an eastward thickening accretionary 

prism of upper Miocene and Pliocene melange. The 

decollement between these deformed abyssal strata and the 

melange is sharply defined and truncates folds and faults in 

the upper plate. The melange wedge overlies basalt of the 

gently dipping ( ~3°) subducting Juan de Fuca plate that can 

be traced from the base of the slope eastward for about 55 

km. The ductile abyssal strata are deformed against the 

steep back stop of the outer arc high that is composed of 

uplifted and folded upper Miocene and Pliocene basin strata 

in the upper plate of fault A. On the Outer Continental 

Shelf a decollement, or roof thrust, separates upper Oligocene and middle Miocene melange from broadly folded and 

faulted upper Miocene and Pliocene bathyal and neritic 

outer shelf basin strata. Folds and faults in these basin strata 

are truncated along the decollement (fig. 3). In Shell Oil 

Company well P-072, the decollement was penetrated at a 

depth of 1 ,550 m. Below the decollement, middle Miocene 

and upper Oligocene sheared and well-indurated siltstone 

and carbonate-cemented sandstone were encountered. A 

marked increase in borehole pressure (near lithostatic), 

interval velocity, and vitrinite reflectance occurs below the 

decollement. The position of the decollement most likely 

was initiated by faulting along a zone of high fluid pressure 

near the regional unconformity at the base of upper Miocene 

beds. 

The upper Oligocene and middle Miocene melange 

and the upper Miocene and Pliocene basin strata above the 

decollement are faulted against rocks of the Oregon Coast 

Range terrane on the inner shelf along left -lateral fault B 

(fig. 3). The decollement is down-dropped east of fault B 

and the Oligocene and Miocene melange most likely underplates rocks of the Coast Range terrane. 

On the midshelf off Grays Harbor, upper Oligocene 

and middle Miocene melange is interpreted from seismicreflection profiles to underplate upper(?) Miocene and 

younger strata along a master shear zone or decollement as 

shown in figure 4. On the inner shelf, however, the melange 

appears to underplate middle Eocene basalt(?) and middle 

and upper Eocene(?) strata of the Coast Range terrane, as 

shown in the eastern part of the profile. Diapiric structures, 

which originate from the overpressured upper Oligocene 

and middle Miocene melange below the megashear, extend 

upward along faults that cut the Miocene and Pliocene strata 

in the upper plate. 

Field mapping on the Olympic Peninsula and the 

interpretation of seismic-reflection profiles on the Washington and Oregon continental margin, all attest to the importance of tectonic underplating in the structural evolution in 

the region. 

FUTURE STUDIES 

The Pacific Northwest Deep Crustal Study program, 

initiated by the U.S. Geological Survey in FY 1991, is a 

broad-scale integrated geologic and geophysical study to 

investigate deep crustal structure of the Pacific Northwest to 

Cenozoic Geologic History of the Oregon and Washington Continental Margin 33 
w 

.f;:o. 

., 

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II) 

c.. 

:r 

(JQ 

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... 

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m 

m 

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r.ll 

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3 

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0 

Ill 

c· 

3 

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~ ~ 

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:r 

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Ill 

II) 

~ 

ri 

::r 

w 

ABYSSAL I 

PLAIN CONTINENTAL SLOPE 

0 

tn 

~1 

~ 

w 2 ~ 

53 

w 

Accretionary prism 

~ 

n 1 '"lmu Tmv c=> JUAN DE FUCA PLATE c=> 

c:::::>Tmv 

E 

SHELLOILCO. INNER 

OUTER CONTINENTAL SHELF P-3_72 I CONTINENTAL SHELF v /Oho 

' Qh Qh, ~~~ ~ mOis~' %4~~~--:-;:;~~DU;:_;;: -· --·---~-,~ ~ =-::-- ~-, ~pu'""-...---- ~~~ -~-==--Op--.~~ -t e -- • 

Accretionary prism 

~ 

? Fault A 

Figure 3. Geologic interpretation of a west-trending seismic-reflection profile 

collected by the Exxon Company, U.S.A. off northwest Oregon. Symbols: 

continental slope and abyssal plain; Qls, Holocene landslide debris; Qh, 

Holocene sediments; Qp, Pleistocene strata; Tp-Qp, Pliocene and Quaternary 

strata, undifferentiated; Tp, Pliocene strata; Tmu, upper Miocene strata; 

Tmu-Tp, upper Miocene and Pliocene melange; Tmv, upper Miocene oceanic 

basalt. Outer Continental Shelf: Qls, Holocene landslide debris; Qh, HoloTmm-To 

Fault B Tmm-To(?) 

0 5 10 KILOMETERS 

VE=2 

2 

3 

4 

5 

6 

7 

cene sediments; Qp, Pliocene strata; Tpu, upper Pliocene strata; Tpm, middle 

Pliocene strata; Tmu-Tpl, lower Pliocene and upper Miocene strata, undifferentiated; Tmm-To, middle Miocene and lower Pliocene melange. Inner 

continental shelf: Qh, Holocene sediments; Qp, Pleistocene sediments; Tp, 

Pliocene strata; Tm, Miocene strata; To, Oligocene strata; Toe, Oligocene and 

Eocene strata, undifferentiated; Tev, Eocene volcanics; Tern, middle Eocene 

strata; Tmm-To, middle Miocene to Oligocene melange. 
1"'1 

II) 

:J 

0 

N 

0 

r;· 

~ 

w ,.-... 

en 

~0 

0 

~ 1 

~ 

~2 

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~· ~ 5 

~6 

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s~ 

E 

0 4 KILOMETERS 

a. 

:r 

VE=2.6 I I I I I 

I'D 0 

0 a1 Figure 4. Interpreted time-section of migrated multichannel seismic-reflection 

g profile on the continental shelf off Grays Harbor, Wash. The upper Oligocene and 

~ middle Miocene melange is inferred to underplate broadly folded strata of late 

c. Miocene and Pliocene age. Near the eastern edge of the profile, the melange 

~ appears to underplate middle(?) Eocene basalt and upper Eocene(?) strata. (II 

:::r 

:r 

5 

:J 

1"'1 

0 

a 

:r 

II) 

:J 

£ 

E 

aa 

:r 

~ 

1.11 

2 MILES 

Symbols: Qp-Qh, Pleistocene and Holocene sediments, undifferentiated; TmuTp, upper miocene and Pliocene strata, undifferentiated; Tes, upper Eocene 

strata; lev, middle Eocene basalt. Open arrows show direction of tectonic 

underplating. 
better understand the entire subduction margin, forearc, and 

the active volcanic arc. 

Seismic-reflection and refraction profiles on the EEZ 

and adjacent Coast Range to be acquired under this new 

program will assess the potential of great earthquakes along 

the Cascadia subduction zone, as well as seek answers to 

other important geologic questions, such as: 

• What is the geometry of the subduction zone and the 

eastward extent of the underplated accretionary prism? 

• Do major faults, such as the Fulmar, extend to or cut the 

Juan de Fuca plate? 

• What is the role of tectonic underplating in basin evolution in the Coast Ranges? 

36 Proceedings, 1991 EEZ Symposium on Mapping and Research 

• Does the geometry of the Juan de Fuca plate vary along 

strike of the continental margin? Is it segmented by 

northwest-trending strike-slip faults? 

• Is there evidence that the Juan de Fuca and North 

American plates are coupled? 

REFERENCE CITED 

Snavely, P.D., Jr., and Wells, R.E., 1991, Cenozoic evolution of 

the continental margin of Oregon and Washington: U.S. 

Geological Survey Open-File Report 91-441-B, 34 p. 
Strike-Slip Faults Associated with the Cascadia 

Convergence Zone Off Oregon 

LaVerne D. Kulm 

Oregon State University 

Abstract 

Major strike-slip faults were recently discovered off 

Oregon by use of a combination of multibeam swath 

bathymetry, SeaMARC-1A sidescan sonar, and multichannel seismic records. One of these left-lateral faults occurs 

on the abyssal plain and crosses the juan de Fuca-North 

American plate boundary, cutting the accretionary wedge. 

Multibeam bathymetry illustrates several manifestations of 

the fault zone, including a large abyssal hill and pop-up 

plateaus, a large indentation within the wedge, and sigmoidal bending of fold axes along the trend of the fault. 

The implications of these faults in the plate tectonic 

framework of the Cascadia subduction zone are being 

studied. Swath mapping technology contributed directly 

to the discovery of these new features, whose structures 

were subsequently imaged with deep penetration seismic 

reflection surveys. 

Strike-Slip Faults Associated with the Cascadia Convergence Zone Off Oregon 37 
The NOAA VENTS Program: Interdisciplinary Studies of 

Hydrothermal Processes on the Juan de Fuca Ridge 

Robert Embley 

National Oceanic and Atmospheric Administration 

Abstract 

Since 1984, studies of the vent systems on the juan de 

Fuca Ridge have been conducted through a closely coordinated approach that incorporates a wide range of expertise. This interdisciplinary approach, combined with the 

ready access to the study site off Oregon and Washington, 

has yielded some important insights into the oceanic 

hydrothermal system. One of the most fundamental dis38 Proceedings, 1991 EEZ Symposium on Mapping and Research 

coveries is that very large expulsions of hydrothermal 

fluids (megaplumes) are linked to episodes of sea-floor 

spreading. The discovery of the megaplumes led directly 

to the documentation of a volcanic eruption that occurred 

during the same period of time (mid-1980's). The scientific 

community is now developing plans for a sea-floor observatory and long-term monitoring of portions of the juan 

de Fuca Ridge, so this area is likely to remain a focus of 

research for many years. 
Joint SIO-NOAA Geophysical Studies on the Southern 

Juan de Fuca Ridge 

john A. Hildebrand and Spahr C. Webb 

Scripps Institution of Oceanography 

Christopher G. Fox 

National Oceanic and Atmospheric Administration 

Abstract 

We present results from a suite of geophysical experiments conducted on the southern juan de Fuca Ridge by 

the National Oceanic and Atmospheric Administration 

VENTS programs. During these geophysical experiments 

we looked for evidence of continuing sea-floor volcanic 

activity at the axial volcano and the megaplume sites on 

the southern Juan de Fuca Ridge. These experiments will 

become major components of doctoral theses of three 

graduate students at the Scripps Institution of Oceanography. The geophysical studies allow the structure of 

sea-floor magmatic and hydrothermal circulation to be 

delimited and thus provide constraints on the relation of 

structure to magmatic activity. A seismic refraction experiment, in which ocean-bottom seismographs (OBS) and an 

airgun array were used, determined shallow crustal seismic velocity and attenuation by observing the propagation 

of seismic waves through the sea floor. These OBS also 

recorded numerous microearthquakes along a 16-km segment of rise crest near the megaplume site that is by 

Cleft-Vance overlapping right zone. Bottom-gravity stations and a surface-gravity survey provide information on 

crustal density. Variations of seismic velocity, attenuation, 

and density are related to zones of hydrothermal and 

magmatic activity. 

Joint SIO-NOAA Geophysical Studies on the Southern Juan de Fuca Ridge 39 
NOAA's Multibeam Bathymetric Surveys and Products off 

Hawaii and the Northeast Pacific Margin 

Gerald B. Mills and Richard B. Perry 

National Oceanic and Atmospheric Administration 

Abstract 

The National Oceanic and Atmospheric Administration began systematically mapping the continental slope 

of the U.S. Exclusive Economic Zone by using multibeam 

mapping systems in 1984. Over 106,000 square nautical 

miles have been mapped since inception of this Ocean 

Mapping Program. Fifty-six 1 :100,000-scale bathymetric 

maps with a 20-m contour interval, mostly covering onehalf degree of latitude by one degree of longitude, are 

now available in black and white or printed form . Of 

these, 6 maps are off Hawaii, 4 maps off Alaska, 12 maps 

off Oregon, and 13 maps off California. Gridded data sets 

are also available for each printed map. 

INTRODUCTION 

The National Ocean Service (NOS) of the National 

Oceanic and Atmospheric Administration (NOAA) is 

charged with the responsibility to survey and chart all the 

coastal waterways and navigable inland waterways of the 

United States and its possessions and produce related 

nautical products. This national program for nautical charting is carried out by the Nautical Charting Division of the 

Coast and Geodetic Survey, an office of the NOS. 

Conventional nautical charts are used for navigation 

and show the nature and shape of the coast, depths of water, 

marine hazards, aids to navigation, and other information 

required for safety purposes. These charts are made up of 

detailed, large-scale plots of surveyed depths called hydrographic surveys that are generally twice the scale, or larger, 

of any chart to which they are applied. 

Hydrographic surveys are used extensively by the 

public and by government agencies for research, engineering, and development purposes and are known for their high 

degree of accuracy. Single-beam echo sounders replaced 

the lead line in about 1933 as the primary method for 

determining depths during hydrographic surveys. Although 

single-beam systems are still used in shallow water, new 

multibeam echo sounders recently have been adopted for 

obtaining depth information in deeper areas of the ocean. 

40 Proceedings, 1991 EEZ Symposium on Mapping and Research 

NOAA'S OCEAN MAPPING PROGRAM 

NOAA's Ocean Mapping Program was established in 

response to the Presidential Proclamation of March 10, 

1983 , whereby the United States claimed sovereign rights 

and jurisdiction over the Exclusive Economic Zone (EEZ). 

The U.S. EEZ extends seaward 200 nmi from the coast, 

encompassing nearly 3.4 million nmi2

• It includes the 

relatively well-charted continental shelf, defined by depths 

less than approximately 200 m, and the vast, largely 

unexplored deeper areas of the continental slopes and rises. 

The areal distribution of the U.S. EEZ by region and depth 

is shown in figure 1. 

Detailed mapping of the EEZ was begun in 1984 by 

utilizing the multi beam echo sounders, which permitted 100 

EXCLUSIVE ECONOMIC ZONE AREAL DISTRIBUTION 

(in thousands of square nautical miles) 

Thousands 1.200 r---------------------

1~00 ~-----------------

800 ~---------

soo r----------

4oo r-----------

ATL CAR GoM PAC AK(S) AK(N)• HI• PAC IS• 

Region 

- 0 - 140 m ~ 140 - 1.000 m CJ 1.000 - 3,000 m - , :WOO m 

.. Further breakdown unavailable 

Figure 1. Distribution of depths in thousands of square 

nautical miles within the U.S. Exclusive Economic Zone. 

ATL, Atlantic Coast (Maine to Key West); CAR, Carribean 

(Puerto Rico & Virgin Islands); GoM, Gulf of Mexico (Key 

West to Texas-Mexico Border); PAC, Pacific Coast of 

United States (California, Oregon, Washington); AK(S), 

Alaska South of Aleutians; AK(N), Alaska North of Aleutians; HI, Hawaiian Islands; PAC IS, Guam and U.S. Pacific 

Trust Territories. 
percent coverage of the ocean bottom for the first time. 

These systems are operated by NOAA in depths greater than 

150m to produce bathymetric maps, which are essentially 

topographic maps of the sea floor. The detailed contours of 

these maps provide information on the size, shape, and 

location of significant underwater features. Unlike nautical 

charts, bathymetric maps do not contain navigational information and should not be used for navigation. These maps, 

and the digital data used to create them, can be used in the 

following ways: 

• Improve and enhance nautical charts and bathymetric 

maps, 

• Better manage the living and mineral resources of the 

EEZ, 

• Model geological and geophysical hazards affecting 

coastal regions and offshore construction, 

• Model physical oceanography of continental and island 

margins including factors affecting water-mass movements, acoustic propagation paths, and sediment transport regimes, 

• Improve targeting of scientific research efforts involving 

manned submersible investigations and remotely operated vehicle operations, and 

• Discover and (or) define unique or previously unknown 

marine environments for designation as marine sanctuaries or protected areas 

MULTIBEAM MAPPING METHODS 

The NOAA ships Surveyor, Discoverer and Davidson 

have collected data in the Pacific EEZ utilizing hullmounted multibeam sea-floor mapping systems. Surveyor 

and Discoverer are equipped with the SeaBeam system, 

which operates at 12kHz, provides bottom coverage equal 

to 70 percent of the water depth, and is used by NOAA in 

water depths between 600 m and full oceanic depths. 

Davidson, which is currently inactive, used the Bathymetric 

Swath Survey System (BSSS) to map the ocean bottom in 

water depths between 150 m and 600 m. The BSSS operates 

at 36 kHz, yields bottom coverage equal to 250 percent of 

water depth, and is normally used between 150m and 600 

m water depth. 

The mission of these ships during survey operations is 

to attain 100 percent bottom coverage (that is, all of the 

bottom has been ensonified) of the survey area and to 

maintain International Hydrographic Organization (IHO) 

standards for map accuracy. Therefore, 90 percent of all 

soundings obtained during EEZ surveys must have a horizontal positioning error of less than 50 m. Highly accurate 

navigation systems such as ARGO, a medium-frequency 

phase-comparison system, and the satellite-based Global 

Positioning System (in differential mode) have been used to 

achieve this level of accuracy. 

A special procedure, called a patch test, was developed by NOAA to determine the errors associated with the 

alignment of the SeaBeam system multibeam sonar array as 

well as any roll and pitch biases (Wheaton, 1988; Herlihy 

and others, 1989). Crews (1990) discusses a similar technique for the second generation BSSS, the Hydrochart II. 

Both procedures use manual reduction methods that are 

labor intensive, somewhat subjective, and often produce 

inconsistent final results. 

TAU Corporation has recently developed software 

under contract to NOAA to automate and improve the patch 

test for SeaBeam systems utilizing a Sun SP ARC station I. 

Initial analysis indicates excellent repeatability of bias 

determination. Standard operating procedures are being 

developed for the NOAA Beam Alignment Workstation, as 

it is called, by personnel from NOAA's Office of NOAA 

Corps Operations, Software Engineering Branch. It is 

anticipated that this system will be fully operational for the 

fiscal year 1992 field season. No automated procedure has 

yet been developed for the Hydrochart II system. 

The variation of sound velocity in seawater due to 

changes in salinity and temperature is monitored to correct 

soundings, and their position, for the effects of refraction. 

This is accomplished by periodically making conductivity, 

temperature, and depth (CTD) observations supplemented 

by daily expendable bathythermographs (XBT' s) (Hillard 

and Lynch, 1989). The goal of such rigorous field procedures is to achieve soundings that are accurate within 1 

percent of true depth. 

RECENT DEVELOPMENTS IN DATA 

PROCESSING 

Shipboard data-acquisition and processing software 

allows generation of contour plots, point sounding plots, 

colored symbol plots, and navigation track plots that aid 

shipboard personnel in error detection and filtering (Theberge, 1990). Erroneous or questionable soundings from 

multibeam sonar data create artifacts in contour plots 

(Armstrong, in press). Until recently, these artifacts could 

be removed only by identifying the approximate time of the 

questionable sounding and "windowing" out that time from 

the raw data (good soundings with the same time were also 

windowed out). 

In 1990, a software "prefilter" (TSCAR) was developed to identify and remove automatically these soundings 

from the raw data sets and place them in a special "cull" 

file. This filter essentially compares a candidate sounding to 

a weighted average of 20 of its nearest neighbors (only 

nonzero depths are used). This neighborhood is illustrated 

in figure 2. Soundings along the same beam are weighted 

twice that of soundings along the other two beams (Herlihy, 

1992). Preliminary results from 1991 data indicate that 

TSCAR "culls" about 0.05--0.5 percent of multibeam 

soundings while greatly reducing processing time. 

Computer software was developed in the early years 

of the Ocean Mapping Program to select statistically sigNOAA's Multibeam Bathymetric Surveys and Products off Hawaii and the Northeast Pacific Margin 41 
Ping Times 

90-273 09:43:28 801 

90-273 09:43:30 0 

90-273 09:43:32 0 

90-273 09:43:34 793 

09-273 09:43:37 799 

09-273 09:43:40 779 

09-273 09:43:43 778 

09-273 09:43:46 0 

90-273 09:43:49 776 

t BeamN-1 

Depths 

792 

781 

776 

778 

778 

782 

t ·current Beam• 

BeamN 

(Extra weight) 

784 

782 

776 

778 

0 

779 

t Beam N+1 

Nonzero soundings within 

box are used to compute 

Neighborhood Average 

"Comparison Sounding" 

TSCAR Prefilter Neighborhood (SEABEAM) 

Figure 2. Field of soundings from which the prefilter 

program TSCAR identifies questionable soundings. 

nificant soundings from this corrected raw data set. This 

step was necessary because of the inability of minicomputers of the mid-1980's to process the huge multibeam 

sounding data sets efficiently, typically 0.5-2 million 

soundings per survey. (For reference, conventional hydrographic surveys consist of 12,000-18,000 soundings.) 

Maximum, minimum, and average depths (that is, the 

observed depth which is closest to the arithmetical average) 

are selected for unit areas approximately 250 m on a side 

throughout the survey area and are then gridded to a 

uniformly spaced 250-m Cartesian interval (Herlihy and 

others, 1988). 

The increased speed and memory capability of modem minicomputers has permitted the recent development of 

a software routine, V AXCOPALL, to bypass the sounding 

selection process. It converts all soundings to latitude and 

longitude before the gridding process, not just selected 

soundings. The resulting gridded data and bathymetric 

maps are consequently more detailed and accurate. 

One hundred and seventy-six multibeam surveys 

covering almost 58,000 nmi2 have been completed off the 

coasts of Oregon, California, Alaska and Hawaii (fig. 3). 

Multibeam surveys offthe coast of Washington are classified by the Department of Defense and are not available to 

the general public. Data from these surveys have been used 

to compile 35 bathymetric maps, each of which encompasses between 1 ,200 nme and 1, 700 nmi2

. Each map 

measures 0.5° of latitude by 1 o of longitude except those in 

Alaska that are 11/2° of longitude wide due to convergence of 

the meridians. 

Surveys conducted off the southern coast of the Island 

of Hawaii in 1991 are of special interest. For the first time, 

the Department of Defense's new satellite navigation sys42 Proceedings, 1991 EEZ Symposium on Mapping and Research 

tern, the Global Positioning System (GPS), was used in 

differential mode for vessel positioning for multibeam 

survey operations. 

No additional surveys are scheduled in the Pacific 

during 1992 due to other higher priorities for NOAA 

vessels. However, bathymetric mapping will continue in the 

Gulf of Mexico and off the coast of North Carolina utilizing 

differential GPS (DGPS) with correctors being supplied by 

U.S. Coast Guard radiobeacons. Experiences gained from 

this use of DGPS will undoubtedly be useful in future 

operations in the Pacific. 

PRODUCTS 

The 1:100,000 scale printed multibeam bathymetric 

maps show Minerals Management Service lease block 

areas, Loran-e lines of position, and include a threedimensional view of the map area. Regional physiographic 

images are created by combining the three-dimensional 

views of six adjacent maps. The resulting products, which 

cover over 9,000 nmi2 of the sea floor, provide an excellent 

means of visualizing underwater features and are very 

useful teaching aids for students of geology and physical 

geography. One physiographic image covers the continental 

slope along the central California coast, while the other is in 

the Gulf of Mexico. 

The gridded data used to produce the contours and 

three-dimensional images are available on a high-density 

floppy disk in both the original UTM format (250m) and a 

geographic grid (every 15 seconds of latitude and longitude). Full resolution multibeam data consisting of every 

collected sounding (Grim, this volume) will be available in 

the near future from the National Geophysical Data Center 

(NGDC) in Boulder, Colo. 

In addition to multibeam maps, bathymetric maps 

have been compiled from the single beam and leadline 

hydrographic surveys discussed above. While the density of 

the soundings from these surveys is not as great as that from 

multi beam surveys, great care has been taken to develop 1-

m and 2-m depth contours over the entire continental shelf. 

Regional bathymetric maps at 1:1,000,000 scale are 

available for most of the waters within the EEZ of the 

continental United States. Most nearshore areas also are 

covered by larger scale 1:250,000 scale bathymetric maps 

and there is limited coverage with 1:100,000 and 1:24,000 

scale maps. 

Two other products utilize detailed bathymetric contours. Topographic/Bathymetric maps, also known as topobathys, are detailed multipurpose maps that show both the 

NOS bathymetry and the U.S. Geological Survey land 

topographic information. These allow geologic features to 

be followed across the land (sea) interface and are particularly useful for coastal zone management and resource 

assessment. 
ALASKA EEZ 

BATHYMETRIC INDEX MAP t---'----'----'--'------'---'---'-----'----'----'--.J..._---f 61N 

Updated Odobtr 1991 

~~r-~-~-T--,--r-,--~~~~-~~~N 

ISS~ IS4~ IS3~ 151~ lSI~ ISO~ 149~ 148~ 147~ 146~ 14S~ 144~ 143~ 

HAWAII 

BATHYMETRIC 

EEZ 

MAP INDEX 

2!N 

20N 

19N 

180154W 

IBN 

AREA SURVEYED = 1§§1 

~ 17N 

"V ~ 

Updated October 1991 

~~., 

16N 

158\.1 157\,/ 156\.1 155\.1 154\.1 

WASHINGTON/OREGON EEZ 

BATHYMETRIC MAP INDEX 

AREA SURVEYED 1111 

48N 

47N 

46N 

PORTLIND 

45N 

OR 

43N 

CA 

Updated October 1991 +-'-~-----.--~-,---'-r------.--~---1 41N 

12911 12811 12711 12611 12511 12411 12311 12211 12111 

CALIFORNIA EEZ 

BATHYMETRIC MAP INDEX 

Area Surveyed = • 

41N 

NV 

40N 

CA 39N 

38N 

37N 

36N 

35N 

34N 

Updated October 1991 

+--~-~-....>..---~-----r--,--~---l. 33N 

127\1 1261J 125\/ 1241J 123'w' 1221J 121\rl 120\/ 119\1 

Figure 3. Index maps showing areal coverage and map index for NOAA's EEZ surveys. 

NOAA's Multibeam Bathymetric Surveys and Products off Hawaii and the Northeast Pacific Margin 43 
Bathymetric fishing maps, produced at 1:100,000 

scale, are designed primarily for use by commercial and 

sport fishermen. This series of maps contains Loran-C 

rates, distribution and identification of bottom sediment 

types, and known bottom obstructions, in addition to the 

standard bathymetric contours. This product is intended to 

aid fishermen and other users in the identification of 

sea-floor features, the location of potential fishing grounds, 

and the locations of wrecks or obstructions that might cause 

gear damage. 

At present, the only digital depth data available on the 

continental shelf is the sounding information from single 

beam hydrographic surveys since 1933. This depth information is available in digital form from NGDC. 

Several areas have had no "modem" echo soundings 

collected and hence, appear as holes in the NGDC data. 

Preliminary plans are being made to digitize the pre-1933 

hydrographic surveys in these holes and produce detailed 

digital bathymetric data for use in various marine Geographic Information Systems. Input is requested from 

potential users to determine the requirements for vector data 

(digital bathymetric contours) and raster data (digital gridded data). Area and depth priorities also are being determined. Comments on the usefulness of this type of data can 

be submitted by contacting: 

Graphic Mapping Unit (N/CG2241) 

National Ocean Service, NOAA 

6001 Executive Blvd. 

Rockville, MD 20852 

Telephone 301-443-8855. 

NOS annually publishes a free catalog that updates 

product availability and is entitled "Bathymetric Mapping 

Products, Catalog 5." This catalog and any additional 

information about bathymetric products can also be 

obtained from the above address. Other possible products 

being discussed include a small format atlas of available 

maps and their three-dimensional imagery, slide sets for 

students and teachers, and CD-ROM with numerous data 

sets. It even is possible to produce videos from this data that 

44 Proceedings, 1991 EEZ Symposium on Mapping and Research 

give the impression of "flying" through the spectacular 

scenery of our continental margins (Matula and Mills, 

1991). 

REFERENCES CITED 

Armstrong, A.A., Ill, in press, NOS hydrographic manual fifth 

edition: National Oceanic and Atmospheric Administration 

Coast and Geodetic Survey, Rockville, Md. 

Crews, N.L., 1990, Depth accuracy analysis for the intermediate 

depth swath sonar system (IDSSS), Hydrochart II: The 

Hydrographic Journal, no. 57, p. 11-16. 

Herlihy, D.R., Hillard, B.F., and Rulon, T.D., 1989, National 

Oceanic and Atmospheric Administration SeaBeam System 

"Patch Test": International Hydrographic Review, v. LXVI, 

no. 2, p. 119-139. 

Herlihy, D.R., Matula, S.P., and Andreasen, C.A., 1988, Swath 

mapping data management within the National Oceanic and 

Atmospheric Administration: International Hydrographic 

Review, v. LXV, no. 2, p. 55-74. 

Herlihy, D.R., Stepka, T.N., and Rulon, T.D., 1992, Filtering 

erroneous soundings from multibeam survey data: Proceedings of the 1992 U.S. Hydrographic Conference, p. 103-110. 

Hillard, B.F., and Lynch, P.D., 1989, NOS swath mapping 

program-Advances in the acquisition, processing and presentation of multibeam survey data, in Proceedings of the 

1989 Canadian Hydrographic Conference, p. 56-67. 

Matula, S.P., and Mills, G.B., 1991, Creating modem ocean 

bathymetric maps in the 1990's and beyond, in Proceedings 

of the 1991 Canadian Hydrographic Conference, p. 10.1-

10.15. 

Theberge, A.E., Jr., 1990, National Oceanic and Atmospheric 

Administration multibeam mapping in the Gulf of Mexico, in 

Exclusive Economic Zone Symposium on Mapping and 

Research-Federal-State Partners in EEZ Mapping, Reston, 

Va., 1989, Proceedings: U.S. Geological Survey Circular 

1052, p. 71-75. 

Wheaton, G.E., 1988, Patch test, a system check for multibeam 

survey systems, in Proceedings of the U.S. Hydrographic 

Conference, p. 85-90. 
GLORIA Mapping in the Pacific Basin 

David A. Cacchione and james V. Gardner 

U.S. Geological Survey 

INTRODUCTION 

On October 29, 1991, the U.S. Geological Survey 

(USGS) completed the collection phase of the entire 

reconnaissance-scale mapping of the U.S. Exclusive Economic Zone (EEZ) surrounding the 50 States, exclusive of 

the Arctic Ocean and shallow northern Bering Sea sectors. 

The main mapping has been accomplished by the use of the 

digital GLORIA III sidescan-sonar system (Somers and 

others, 1978; EEZ-SCAN 84 Scientific Staff, 1986). The 

effort began in May, 1984, following the proclamation of 

the EEZ by President Reagan in March 1983. The USGS 

program, EEZ-SCAN, has surveyed a total of more than 7. 5 

million km2 in the EEZ, 6 million km2 of which are in the 

Pacific Basin. The Pacific cruises have logged approximately 270,000 km of ship tracks during 34 cruises totaling 

about 850 days at sea. More than 200 scientists, engineers, 

technicians, and ship's crew have participated in the at-sea 

work, and more than 200 scientific papers, abstracts, and 

talks have been produced for national and international 

earth-sciences journals, at national and international scientific meetings, and at government and university seminars. 

Although the emphasis of EEZ-SCAN has been to 

collect overlapping, continuous images of the sea floor by 

using the GLORIA system, more than a quarter of a million 

line kilometers of regularly spaced gravity, magnetic, highand low-resolution seismic, and bathymetry data have been 

simultaneously collected. Consequently, the EEZ-SCAN 

program has now accomplished the most systematic, largescale, continuous mapping ever produced of the sea floor. 

Most of these data reside in the data archives at the National 

Geophysical Data Center, NOAA, Boulder, Colo., and are 

available to the public. 

SCOPE OF THE EEZ-SCAN PROGRAM 

The EEZ mapping and research plan developed during 1983 and early 1984 layed out a systematic mapping 

program that would complete the mapping of the EEZ 

deeper than 200 m surrounding the 50 States, exclusive of 

the Arctic Ocean, by late 1991. The plan subdivided the 

U.S. EEZ into areas that represent spatially and geologically coherent regions (fig. 1) so that complete mapping of 

one region would be accomplished before work in another 

region was begun. The breakdown of the EEZ regions 

consists of the Atlantic margin, the Gulf of Mexico and 

Caribbean, the Pacific margin, the Bering Sea, the Aleutian 

Islands, the Gulf of Alaska, and Hawaii. 

Mapping of the EEZ of the U.S. Trust Territories 

(about 3 million km2

) is planned for initiation in 1993 or 

early 1994 and will require approximately 5 yr to complete. 

These mapping surveys will utilize an upgraded GLORIA 

sidescan system that collects not only digital imagery but 

also collects bathymetric data over a sea-floor swath only 

slightly narrower than the imagery data (see discussion 

below). 

The original plan called for complete digital image 

processing of the sidescan images to correct for geometric 

and radiometric distortions in the raw data and to digitally 

mosaic the images into quadrangles. The data were to be 

published in a series of regional atlases at a scale of 

U.S. EEZ 

Figure 1. Map of the U.S. Exclusive Economic Zone. U.S. 

Trust Territories includes johnson Island (JI), Wake Island 

(WI), Palmarya Island (PA), Jarvis Island (JA), American 

Somoa (AM), Howland-Baker Islands (H-B), and Guam and 

the Northern Marianas (G). The total area of the U.S. EEZ 

is 13,200,000 km2

• 

GLORIA Mapping in the Pacific Basin 45 
1:500,000, each regional atlas to be published within 2 yr of 

the completion of the data collection in that region. This 

phase of the EEZ mapping has been on schedule since 1984 

and was successfully completed with no delays. A second 

phase of the EEZ-SCAN program was to initiate a systematic "ground truthing" or follow-on studies of the imagery 

and geophysical data in all of the areas mapped. This phase 

was designed to provide a derivative set of geologic maps of 

each region to closely follow in time the publication of the 

imagery. The ground-truthing phase has lagged behind the 

image-mapping phase because of the lack of ship time and 

funding. However, several ground-truthing cruises have 

already been carried out, and their results are undergoing 

analyses; a few have already been published (Karl and 

others, 1989; Gardner and others, 1991). 

PACIFIC EEZ MAPPING 

The initial EEZ-SCAN mapping cruises in 1984 were 

carried out along the Pacific margin EEZ from the Mexican 

border to· the Canadian border. Two Pacific regions were 

started in 1986: the Bering Sea, and the Hawaiian EEZ. 

Weather conditions in the Bering Sea permitted only about 

3 months of mapping per year; consequently, two 3-month 

at-sea seasons were required to complete the mapping of the 

Bering Sea. Following the completion of the Bering Sea 

EEZ in 1987, the Aleutian Islands EEZ was started; it was 

completed in 1989. The Hawaiian EEZ encompasses more 

than 2.3 million km2 and has required 18 approximately 

1-month cruises to completely map the area. The mapping 

of the Hawaiian EEZ was completed in October, 1991. 

STATUS OF DATA PROCESSING AND ATLAS 

PUBLICATIONS 

The program plan originally developed in 1983 called 

for the orderly publication of regional atlases, each being 

released about 2 yr after the field mapping was completed. 

Each atlas consists of GLORIA images of 2° of latitude x 

2° or 3° of longitude mosaicked at a scale of 1:500,000, 

together with overlays of bathymetry and geological interpretations. In addition, each atlas presents all of the 

navigation, gravity, magnetic, and seismic-reflection data, 

making the atlas a complete data set for anyone needing to 

investigate an area within the EEZ region. 

Two Pacific EEZ atlases have been published as of 

this writing; the West Coast EEZ off California, Oregon, 

and Washington (EEZ-SCAN Scientific Staff, 1986), and 

the Bering Sea EEZ (Bering Sea EEZ-SCAN Scientific 

Staff, 1991). The data for the Aleutian Islands EEZ are 

presently being digitally mosaicked, and the atlas should be 

published soon. The Hawaiian EEZ is so large that the area 

was subdivided into three subregions: an eastern, central, 

46 Proceedings, 1991 EEZ Symposium on Mapping and Research 

and western Hawaiian EEZ. The data from the eastern 

Hawaiian EEZ have been digitally mosaicked, and the atlas 

is currently in production. The eastern Hawaiian EEZ atlas 

is expected to be released to the public soon. The central 

and western Hawaiian EEZ data collection has just been 

completed; the data have already been processed, and 

digital mosaicking is in progress. The atlas for the central 

and western Hawaiian Islands region should be released 

during the next 2 yr .. 

Once an atlas is generated for a region, the navigation, sidescan-sonar, and geophysical data are reformatted 

and put on a CD-ROM. The CD-ROMs are distributed to 

the user community through the USGS-NOAA Joint Office 

for Mapping and Research in the EEZ, Reston, Va. Presently, CD-ROMs have been produced for the Gulf of 

Mexico EEZ, the Atlantic margin EEZ, and the Pacific EEZ 

off Washington, Oregon, and northern California. The 

CD-ROMs that are presently available include acquisition 

software for IBM-PC's and compatibles with Video Graphics Array or better graphics. Users of non-IBM-PC/ 

compatables can view the image files by using publicdomain software or commercial image-processing 

packages. The next generation of these CD-ROM's will 

include acquisition software for both Macintosh computers 

as well as IBM-PC's and compatibles. 

Apart from the atlases and CD-ROM's, more than 65 

scientific articles in professional journals have been generated from this program, as well as an equal number of 

abstracts and talks at national and international scientific 

meetings. A total of 242 publications of all kinds have been 

published to date utilizing data collected during the EEZSCAN program. 

THE GLORIA SYSTEM 

The revolutionary aspect of the EEZ-SCAN program 

is the systematic use of the Geological LOng-Range 

Inclined Asdic (GLORIA) system. The simultaneously 

deployed gravity, magnetic, and seismic systems are basically the routine tools that have been used in marine 

geological and geophysical studies for nearly three decades. 

What makes the use of the GLORIA system so revolutionary is that the system is capable of collecting a swath of 

imagery of the sea floor that is 45 km wide as the ship 

transits at speeds up to 10 knots. This imaging range allows 

20,000 km2 of sea floor to be mapped each day, an area 

equivalent to the combined size of the States of New Jersey 

and Delaware. The data have a spatial resolution of about 

50 m, making the images equivalent to a marine Landsat 

system. However, the GLORIA system maps the sea floor 

with sound, not electromagnetic radiation. 

The USGS GLORIA III system was designed and 

built for the USGS by the Institute of Oceanographic 
USGS GLORIA MK III.\~ .. 

- -- '-' 

GPS 

~ 

~ 

Figure 2. Schematic diagram of the upgraded USGS 

GLORIA Ill system. The new system will be able to 

simultaneously collect co-registered sidescan-sonar 

images and phase bathymetry at ship speeds of 8-10 

knots. GPS, Global Positioning System. 

Sciences (lOS), Wormley, United Kingdom. Engineers and 

scientists of the lOS staff have accompanied the USGS 

teams on each of the cruises to ensure proper performance 

from the system and at-sea repair in the event of system 

failure. The details and operation of the GLORIA system is 

given in Somers and others ( 1978) and EEZ-SCAN 84 

Scientific Staff (1986). Briefly, the GLORIA system is 

composed of two rows of 30-transducers on each side of the 

towed vehicle. The transducers transmit a 6.5-kHz FM 

signal with a 100-Hz bandwidth in a 2-second pulse and 

receive acoustic returns for 30 second. The sound is 

transmitted and received on either side of the towed vehicle; 

the 30-second recording cycle limits the slant range of 

returns to 22.5 km on each side. The received signals are 

correlated, filtered, compressed, and recorded in digital 

format for later image processing both aboard ship and in 

the USGS laboratories. The vehicle is towed about 200 m 

behind the ship at about 50-m depth. Normal mapping 

speeds are between 8 and 10 kts. Mapping is generally 

limited to areas deeper than 200 m because of the concern 

of having the vehicle impact the sea floor in an emergency. 

Mapping operations are carried out in sea states up to and 

including sea states 5 with very little degradation to the 

data. A total of less than 48 hours of down time because of 

equipment failure has occurred over the 7 yr of operation of 

the USGS GLORIA system. 

During January and February, 1992, the USGS 

GLORIA III system will be outfitted with a series of 

upgrades and new capabilities. The major advancement is 

the addition of the ability to obtain bathymetric data over a 

considerable swath of sea floor concurrent with the collection of the sonar imagery (fig. 2). The design provides the 

system with the ability to collect a 30-km swath of digital 

bathymetric values, one depth value for each pixel of 

imagery ( - 750 pixels/scan) within the swath. The depth 

values should be of a quality that will allow automatic 

gridding and contouring at 50-m contour interval with an 

rms error of± 10m. Once operational, all mapping will be 

with routine simultaneous collection and co-registration of 

bathymetry and imagery. 

Another important improvement is the addition of a 

15-m towed line array of receivers attached to the stem of 

the GLORIA vehicle. The towed line array , three times the 

length of the existing transmission array on the vehicle, will 

act as the receiver for the imagery . By lengthening the 

receiver relative to the transmitter, the horizontal beam 

spread should be reduced to less than 1 o, thereby greatly 

reducing target spreading in the far range and providing 

much sharper images. The towed line array has been tested 

during two test cruises and has performed as expected. 

Onboard processing of imagery and bathymetry will 

be added to the seagoing system during the January and 

February 1992 upgrade period. The new capabilities will 

allow the shipboard scientific staff to collect, correct, and 

plot finished navigation, bathymetry, and fully process 

images and bathymetry in near realtime at sea. The bathymetry and imagery will be co-registered so that they can be 

plotted on top of one another, and three-dimensional block 

models can be easily produced. 

SUMMARY 

The EEZ-SCAN project is continuing to process, 

mosaic , analyze, and publish the data already collected 

from the EEZ surrounding the 50 States. Beginning in late 

1993, the program will again set to sea to begin the 

systematic mapping of the U.S. Trust Territories of the 

western Pacific (table 1). This next phase of the program 

will utilize the upgraded USGS GLORIA III system to 

provide digital bathymetry as well as digital imagery of the 

approximately 3 million km2 of EEZ in the U.S. Trust 

Territories. The program is also striving to continue to 

ground truth the remotely-sensed data so as to provide the 

necessary validation to convert the sonar imagery into 

geological maps of the U.S. EEZ. 

Table 1. Area in km2 of the various U.S. 

Trust Territories 

Guam 

Jarvis Island 

Palmarya Island 

American Somoa 

Howland/Baker Islands 

Wake Island 

Northern Marianas 

207, 172 

323, 106 

357,063 

428,064 

425,663 

411,600 

767,634 

GLORIA Mapping in the Pacific Basin 47 
REFERENCES CITED 

EEZ-SCAN 84 Scientific Staff, 1986, Atlas of the Exclusive 

Economic Zone-Western conterminous United States: U.S. 

Geological Survey Miscellaneous Investigations Series 

1-1792, 152 p. 

EEZ-Scan 1984 Scientific Staff (In alphabetical order: Cacchione, 

D.A., Drake, D.E., Edwards, B.D., Field, M.E., Gardner, 

J.V., Hampton, M.A., Karl, H.A., Kenyon, N.H., and 

Masson, D.G., 1988, Physiography of the western United 

States Exclusive Economic Zone: Geology, Feb. 1988, v. 16, 

p. 131-134. 

48 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Gardner, J.V., Field, M.E., Lee, H., Edwards, B.E., Masson, 

D.G., Kenyuon, N., and Kidd, R.B., 1991, Ground-truthing 

6.5-kHz sidescan sonographs: What are we really imaging?: 

Journal of Geophysical Research, v. 96, p. 5955-5974. 

Karl, H.A., Hampton, M.A., and Kenyon, N.H., 1989, Lateral 

migration of Cascadia deep-sea channel in response to accretionary tectonics: Geology, v. 17, p. 144-147. 

Somers, M.L., Carson, R.M., Revie, J.A., Edge, R.H., Barrow, 

B.J., and Andrews, A.G., 1978, GLORIA 11-An improved 

long range sidescan sonar, in Proceedings of the Institute of 

Electrical Engineering on Offshore Instrumentation and Communications, Oceanology International Technical Session J: 

London, BPS Publications Ltd., p. 16-24. 
Sea-Floor Mapping of the Western Canadian Exclusive 

Economic Zone 

Ralph G. Currie, Earl E. Davis, and Brian S. Sawyer 

Geological Survey of Canada 

INTRODUCTION 

With the signing of the United Nations Convention on 

the Law of the Sea in 1983, Canada's jurisdiction over 

marine resources was extended to an oceanic area that 

approaches half the size of the country's total landmass. 

Of the approximately 4.5 x 106 km2 in the Canadian Exclusive Economic Zone (EEZ), approximately 10 percent 

(0.39X 106 km2

) lies off western Canada and is the subject 

of this discussion. The western Canadian EEZ, which is 

approximately the size of Japan, is geologically interesting 

and contains examples of several types of plate tectonic 

boundaries. The northern Juan de Fuca Ridge divergent 

boundary, numerous ridge offsets, two triple junctions, a 

subduction zone and accretionary complex, and several 

transform boundaries all lie within the western Canadian 

EEZ. 

The Geological Survey of Canada (GSC) does not 

have a formally defined program to map the Canadian EEZ, 

but rather the offshore activities have evolved as a logical 

extension of existing programs to map the Canadian landmass. The first phase (1970-1985) extended the magnetic 

and gravity maps of Canada into the offshore. This was 

followed by an expansive phase, approximately 1980-90 

that presented opportunities to diversify data types to 

include industry standard multichannel seismic data, swath 

bathymetry, and both long-range and high-resolution acoustic imagery. Most recently, emphasis has been placed on 

geoscience studies in nearshore and coastal zones. In 

parallel with the major activities alluded to above, there has 

been a variety of site-specific and related studies including 

refraction surveys, heat flow measurement, seismicity, and 

surficial geology. 

TECTONIC SETTING 

The northern Juan de Fuca Ridge system, consisting 

of the Juan de Fuca and Explorer Ridges and the Dellwood 

and Wilson Knolls, is located from a few hundred to a few 

tens of kilometers off the coast of western Canada ending at 

the Queen Charlotte fault system (fig. 1), an active seismic 

boundary between the Pacific and North American plates. 

Over most of the Juan de Fuca Ridge, spreading takes 

place at a rate of about 60 mm per year. The ridge crest 

morphology is similar to that of other medium- to fastspreading-rate ridges; rifting takes place at the summit of a 

high-standing volcanic ridge. Exceptions occur at several 

locations where spreading takes place in deep axial valleys 

as a result of lower spreading rates, proximity to major 

offsets or transform faults, or simply lack of sufficient 

magma supply. Well-defined magnetic anomalies (see fig. 

3) show that the ridge has broken into several discontinuous 

sections in the past 6 m. y. through episodes of ridge 

rotation and rift propagation (Hey and Wilson, 1982; 

Riddihough, 1984). 

A major asymmetry exists across the ridge with the 

large Pacific plate to the west and the small, thickly 

sedimented Juan de Fuca plate to the east, which is being 

fragmented during subduction beneath North America. A 

substantial literature base exists on the plate-tectonic geometry and geological reconstruction of the region. Proceeding 

from the framework proposed by Atwater (1970), a number 

of studies (see Riddihough and Hyndman, 1989; Atwater, 

1989 as well as references cited in this paper) have 

established plates, subplates, and plate boundaries as shown 

in figure 1. 

REGIONAL POTENTIAL FIELD SURVEYS 

From 1972 to 1985, Pacific Geoscience Centre, 

(PGC) in conjunction with the Canadian Hydrographic 

Service and with what is now the Geophysics Division of 

the GSC conducted a series of multiparameter marine 

geophysical surveys off Canada's west coast, which provided the geoscience data base for some of the observations 

noted in the proceeding section. The survey platform was 

the CSS Parizeau, a 65-m oceanographic research vessel. 

The surveys were conducted on lines running normal to the 

coast with a spacing ranging from 5 km on the continental 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 49 
NORTH 

DE FUCA 

N 

g AMERICAN 

PACIFIC 

PLATE 

PLATE 

SOUTH 

GORDA 

PLATE 

CD 

/ 

Mendocino Transform 

Figure 1. Tectonic setting, plate boundaries and part of the western Canadian EEZ. 

50 Proceedings, 1991 EEZ Symposium on Mapping and Research 

PLATE 44° 
ol 200 N. mil• limit 

REGIONAL MULTIPARAMETER SURVEYS 

Bothymetry, GrovHy, Mognetlco 

1172-1185 

P•ctnc Geo•clenc• Cen1re 

Dep•rtm•nt o1 Energy, Mine• end R••ource• 

C•n•d• 

Scolo 1 : s,ooo,ooo 

l.alllbel'tCOitl'-l~)ectloll 

Figure 2. Tracklines for regional geophysical surveys, 1972-85. 

shelf to 10 km in deeper water (fig. 2). The parameters 

measured consistently were bathymetry (12 kHz), gravity, 

and magnetic fields. Single-channel reflection profiling was 

conducted with a reconnaissance line spacing of 30-40 km. 

At all times, only measurement that could be made with the 

ship underway were included in this program. 

These systematic, regional measurements of gravity 

and magnetic fields and bathymetry have been completed 

out to a distance of 200 nm from the west coast of Canada. 

All navigation and potential field measurements plus a large 

proportion of the bathymetric sounding were recorded 

digitally. 

The free-air gravity data were obtained with dynamic 

LaCoste and Romberg gravimeters S56, S41 , or SLl. 

Surveys were initiated in Victoria or Sidney, British Columbia, with intermediate gravity bases ties at Port Hardy, Tasu 

or Prince Rupert, British Columbia, as appropriate. The 

final accuracy is estimate to be ±2 mGal. 

A compilation of magnetic anomaly data is shown in 

figure 3. Data were obtained with a Barringer OM104 

proton precession magnetometer and have been corrected 

for diurnal variations and reduced to an anomaly field with 

respect to the DGRF!IGRF. The mean absolute crossover 

value is 21 nT for 6,800 crossovers. These data were 

merged with aeromagnetic data collected over the Queen 

Charlotte Islands and Vancouver Island to produce a data 

set that spans the marine-terrestrial boundary. 

After applying appropriate gravity base ties, instrument calibration, regional field removal, and magnetic 

diurnal corrections, all the surveys have been merged and 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 51 

• 
• 

140 w 130 w 

500.0 

450.0 

400.0 

350.0 

300.0 

250.0 

200.0 

150.0 

100.0 

50.0 

50 N SON 0.0 

-50.0 

-100.0 

-150.0 

-200.0 

-250.0 

-300.0 

-350.0 

-400.0 

-450.0 

-500.0 

140 w 130 w 

Figure 3. Magnetic anomaly map of the western Canadian EEZ and adjacent islands. 

adjusted on the basis of a crossover analysis, to form a 

uniform data set of the highest standards. 

The gravity and magnetic data are included in the 

recently published "Gravity and Magnetic Maps of Canada" 

(Geological Survey of Canada, 1980, 1987) and the Canadian Geophysical Atlas Series (Geological Survey of Canada, 1990), as well as Decade of North American geology 

(Geological Society of America, 1989) map products. The 

majority of the potential field data is available in digital 

form from the Geophysical Data Centre, Geophysics Division GSC, as well as the National Geophysical Data Center 

in Boulder, Colo. 

ANCILLARY SURVEYS 

The information gathered by the regional survey 

program provided the foundation for further geoscience 

52 Proceedings, 1991 EEZ Symposium on Mapping and Research 

investigations and contributed to mineral and energy exploration on the western margin. It also provided the impetus to 

acquire other data sets to address specific geoscience 

problems. These data sets are discussed below. 

Multichannel Seismic Reflection Data 

These data have been collected under contract typically by using a 3,000-m-long, 120 channel streamer and a 

50-L (6,000 in3

) air-gun array. The data were recorded at a 

4-millisecond (ms) sampling interval with thirty fold shotreceiver redundancy. Scientific results from these surveys 

(fig . 4) that cross the northern Cascadia Basin and accretionary prism (Hyndman and others, 1990), the Queen 

Charlotte sedimentary basins (Rohr and Dietrich, 1990), 

and northern Juan de Fuca Ridge (Rohr and others, 1988) 

provide excellent constraints on crustal structure in all these 

environments. The top of the subducting Juan de Fuca plate 
+ 

52• 

so· 

48" 

46" 

0 

:r 

+ 

~ . •. . . •. 

+ 

+ 

· .. 

· ..

·. +•. 

·. 

·· .. . 

+ 

+ 

+ 

•·· ... • + + 

·· .. 

·· ... + .. + •••• ••• 

+ 

+ 

+ + 

+ + .. .. + + 

+ + 

MULTICHANNEL 

SEISMIC REFLECTION 

DATA 

+ + 

.. .. .. 

+ •••• ••••• 

·•. + 

·· . + 

+ 

.. 

··. +·· ··• ·· . .. + 

' for 

\1 ~ + 

+ 

+ + 

~ ~ 290 

km + 

+ 

+ + 

+ 

+ 1989 

+ + 

+ 

+ 

.. .. ··. ··-t .. .. ·· ... ·· 

+ + 

+ 

Figure 4. Multichannel seismic tracklines. Used with the permission of the Pacific Geoscience Centre (PGC, 1989). 

is imaged to depths as great as 30 km beneath the V ancouver Island continental shelf. 

Seismic Refraction Data 

Refraction studies have been carried out in a number 

of regions in the offshore (fig. 5), including the margin off 

Vancouver Island (Spence and others, 1985; Drew and 

Clowes, 1990) and the Queen Charlotte Islands (Dehler and 

Clowes, 1988; Mackie and others, 1989), Queen Charlotte 

Sound, Hecate Strait (Spence and others, 1990), and across 

Juan de Fuca Ridge (White and Clowes, 1990). These 

studies, typically carried out in cooperation with the University of British Columbia, have defined the velocity 

structure in the region. These data have been integrated with 

other data sets such as gravity (Sweeney and Seemann, 

1990) and used to refine models for epicenter determinations (Wahlstrom and Rogers, 1990). 

Surficial Geology 

The mapping began in 197 5 and has been limited to 

the relatively narrow (5 to 75 km) continental shelf off 

western Canada. The main program elements are ( 1) routine 

grab sampling on a 3. 7-km grid, (2) sidescan sonar and 

high-resolution seismic surveys, and, (3) airgun seismic 

surveying. Complete grain-size analyses have been performed on about one-third of the approximately 12,000 

samples collected (fig. 6), and the results placed in a data 

base (SEDFIL) that is available from the PGC. These data 

have provided the basis for surficial sediment distribution 

maps (Bomhold, 1980, 1982) and other geoscience publiSea-Floor Mapping of the Western Canadian Exclusive Economic Zone 53 
+ 

52• 

so· 

48" 

0 

:t 

+ 

. . . . . . . 

· . 

+ 

•·· ... 

-t ••• 

+ + 

+ 

. + 

+ 

+ 

+ 

+ 

......... 

••••• + 

·•. 

·· .. 

+ •••••••• ••• 

+ 

.. .. 

+ 

+ 

'/Q ;, C.. t! t! t! 

+ + + + 

0 100 200 

km + + 

+ + 

+ 

+ 1989 

+ 

+ 

+ 

\ + 

!-r- + 

··:··············· ••• + 

.. + ~ + + +~ ~~ 

SEISMIC ···... . .. ··· .. .. .. .. .. .. •• •• + ··t .. .. ••• 

·· ... ·· 

REFRACTION + + + LINES 

46" 

+ + 

Figure 5. Seismic refraction profile lines. Used with the permission of the Pacific Geoscience Centre (PGC, 1989). 

cations (Bornhold and Barrie, 1991; Barrie and others, 

1991). 

Other studies have focused on heat flow (Davis and 

others, 1980, 1989, and 1992), conductivity of the sea 

floor-upper crust (Nobes and others, 1986), offshore seismicity (Hyndman and Ellis, 1981; Hyndman and Rogers, 

1981), and single-channel airgun seismic surveys (Davis 

and Seemann, 1981), to mention but a few. 

SWATH BATHYMETRY AND ACOUSTIC 

IMAGERY 

Although the studies already discussed provided a 

wealth of information on the morphology, structures, and 

54 Proceedings, 1991 EEZ Symposium on Mapping and Research 

processes operating in the offshore, new data were required 

to refine geoscience models. These data have been provided 

by the introduction of multibeam echo sounders (Glen, 

1970), and deep-towed and long-range sidescan sonar 

devices (Spiess and Tyee, 1973; Laughton, 1981; Blackinton and others, 1983). These new tools have been used to 

map the active tectonic plate boundaries. 

In 1983, the PGC participated in a SeaBeam mapping 

program with the National Oceanic and Atmospheric 

Administration (NOAA), and a SeaMARC II (surface 

towed, 12kHz, 10-km swath, nominal horizontal pixel size 

of 5 m, co-registered bathymetry) acoustic imaging project 

with the Hawaii Institute of Geophysics. These were both 

conducted over the northern part of the Juan de Fuca Ridge 

system. This was followed by an additional cooperative 

SeaBeam cruise in 1984 that extended the coverage of the 
54-+ 

50• 

+ + 

+ •••••••• 

... ... 

·········•·•• 

··········' + 

. . . . . . . . . . . . . . 

+ + 

. . . 

························ ... 

.. 

·· .. 

·· ... ·· .. ··. 

·· .. + • •• 

•• 

. .. 

+ 

. .. 

+ .. .,. ,· . . · ~- .. : . , .. · .. .,. .. • • • • "'•..s' • . .. , . . . . .. 

+ 

0 

+ 

.. 

+ 

t 

+ + 

100 200 

km + + + 

+ 

+ 

+ 

+ • 

····..• . ;~,., •••• .. . I •. • •••• 

+ •• • • •••• + +·· + .... • 4t.. ·: + •• .. ':"" . .. ··.. ..·· 

BOTTOM SAMPLES 

12,000 

.. ··... ..·· .. .. 

Figure 6. Surficial geology grab sample locations. 

ridge to the north including a detailed survey of the Wilson 

Knolls (fig. 7). 

A joint project with the Lamont-Doherty Geological 

Observatory was carried out in 1984 to acquire SeaMARC 

I (deep-towed, 27 kHz, 2- to 5-km swath, nominal horizontal pixel size 1 m) high-resolution acoustic imagery data 

for detailed geological studies of the northern Juan de Fuca 

and Explorer Ridges (fig. 8). These data were collected 

over areas with existing SeaMARC II coverage because of 

the gain in resolution of about a factor of five over the 

surface-towed SeaMARC II. 

The final year of regional data collection was 1985, 

when additional SeaMARC II date were acquired over the 

ridge system, as well as over the convergent and transform 

margins (fig. 8) (Davis and others, 1986). 

.. .. •• "1 •• •• + .. .. ·· ..... ·· + 

+ 

The bathymetric and imagery data acquired during all 

of these surveys have been compiled and placed in the 

public domain in a number of formats at a variety of scale. 

They were originally released as a series of Open-File maps 

(Davis and others, 1984, 1985, and 1986; Malahoff and 

others, 1985) and most recently as a GSC map series (Davis 

and others, 1987). 

Additional data acquired by the U.S. Geological 

Survey using the GLORIA long-range sonar system off 

western Canada have been made available to the Pacific 

Geoscience Centre that presents opportunities for multispectral analysis of selected regions of the sea floor. These 

areas include parts of the Juan de Fuca Ridge, the Queen 

Charlotte fault, and the deformation front west of Vancouver Island. 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 55 
0 Co iD ~ ~ ~ 

+ 

+ + 

5~ 

+ + 

+' " 52• 

+ + 

+ + + 

50" + + + 

+ + + 

48• + + + 

e AMS 120 + + 

GLORIA Trackline + + 

~ SEABEAM Survey Coverage 46" 

+ 

Figure 7. GLORIA, SeaBeam, and AMS120 coverage. 

Multiyear programs have been proposed to complete 

the systematic bathymetric and acoustic-imagery coverage 

of the western Canadian EEZ. For water depths greater that 

500 m, approximately 6 months of survey time would be 

required to complete the acoustic mapping assuming a 

SeaMARC 11-type system with a nominal total swath width 

of 10 km. A similar commitment would be required to 

acquire swath bathymetry over the regions of greatest 

scientific interest; that is, the tectonic boundaries. An 

additional 14 months would be required to extend this 

coverage to that portion of the margin with less that 500 m 

of water. 

56 Proceedings, 1991 EEZ Symposium on Mapping and Research 

iD 

~ 

iD ., ~ ~ 

+ + + 

0 100 200 

km 

+ 

+ + 

+ + 

+ + + 

QUEEN 

CHARLOTTE 

SOUND 

+ 

+ 

+ 

+ 

+ 

CURRENT ACTIVITIES AND FUTURE 

DIRECTIONS 

C.. 

~ 

+ 

+ 

+ 

+ 

A recent focus at the PGC has been the preparation of 

Ocean Drilling Program proposals to address paleooceanography in the north Pacific and global change, the 

deformation front of the Cascadia accretionary prism, and 

ridgecrest hydrothermal systems within the EEZ. 

Geoscience surveys of some of the northeast Pacific 

seamount complexes have been conducted in support of a 

paleo-oceanography proposal (Bomhold and others, 1989) 
52• 

48• 

46" 

0 

:! 

+ 

. . . . . . . . . . . . . . . . . 

+ + 

+ 

+ + + 

"··················· ... :: ~ . 

. .· ·············· ... :.... . 

. . ············· ... : 

• 1990 SeaMARC I +'•. 

SeaMARC Survey Coverage: •••••• ••• 

- SeaMARC I + 

- SeaMARC II 

+ 

Figure 8. SeaMARC I and SeaMARC II coverage. 

and the North Pacific Transect Ocean Drilling Program 

(ODP) Leg 145 scheduled for summer 1992. 

To collect acoustic imagery and co-registered 

bathymetry data over the deformation front off Vancouver 

Island, a contract was let in 1990 to Williamson and 

Associates, Seattle, Wash., for the use of their deep-tow, 

high-resolution (AMS 120 kHz and SeaMarc IA) sidescan 

sonars. These data were collected to select final drilling 

sites on the Cascadia accretionary prism west of Vancouver 

Island, for Leg 146 scheduled for the fall of 1992. This leg 

will, in part, address questions regarding diffuse fluid 

expulsion from the accretionary prism and its role in 

generating the methane hydrate bottom-simulating reflector 

(BSR), (Davis and Hyndman 1990; Hyndman and Davis, 

1992). 

.. .. 

., ., :. N 1:! 1:! t! t! 

+ + + + 

0 100 200 

km + + + 

+ + + 

+ + + 

This contract was extended, in cooperation with the 

University of Washington, to survey Middle Valley hydrothermal/polymetallic sulphides sites and debris flows on the 

continental margin with their 30-kHz, SeaMARC 1A deeptow sidescan system. This was the final detailed survey 

work on the northern Juan de Fuca Ridge in preparation for 

drilling in Middle Valley (fig. 9) during ODP Leg 139, 

which occurred July 10 to September 11, 1991 (Davis and 

others, 1991). Planning for a second leg of drilling into an 

active ridge crest hydrothermal system, a means was 

developed to seal and instrument cased boreholes in order to 

prevent the thermal and chemical disturbance associated 

with the flow of cold seawater into the hot crustal formations penetrated and to allow the thermal and hydrological 

conditions to be monitored for periods up to 2 yr (Davis and 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 57 
0 ., ., ~ 0 ,. .. ;! ::! ::! \'! \'! \'! 

+ + + + + + 

0 100 200 

54•+ km + + + + + 

+ + + + + 

... + + + + + 

+ + + 

so· 

+ 

+ + + 

•a· + 

+ 

ODP LEG 139 ~ 

MIDDLE VALLEY + + 

+ 

•e· 

Figure 9. Pacific Geosciences Centre 1991 marine program. 

others, 1992). Two such borehole observatories were 

installed during the ODP Middle Valley drilling leg, and the 

first 3 weeks of data were recovered during a subsequent 

submersible program with DSRV ALVIN. Two more borehole observatories will be established in the Cascadia 

accretionary prism during ODP Leg 146. 

In addition to these focused studies of the tectonics 

and hydrogeology in the offshore regions, there has been a 

growing trend to investigate geoscience problems in the 

nearshore and coastal zone. GSC is changing much of its 

marine geological activity to concentrate on culturally 

important issues such as environmental assessments, seabed 

mapping, waste disposal, and seabed stability. Figure 9 

shows that the majority of the cruises for 1991 were in the 

nearshore . 

One exception to this trend, geographically, was 

cruise PGC9104, a cooperative project with Scripps Institution of Oceanography and the Jet Propulsion Laboratory, 

58 Proceedings, 1991 EEZ Symposium on Mapping and Research 

+ + + 

+ 

California Institute of Technology, to directly measure 

convergent rates and deformation associated with convergence using a high-precision acoustic transponder array. 

Instruments were deployed on the approaching Juan de Fuca 

plate and landward of the active frontal thrust fault of the 

accretionary prism. They were left in place and will be 

monitored annually for the next 5 yr. 

A priority project has been initiated to study the 

structure and evolution of the Fraser Delta (PGC910 1, 

PGC9103, PGC9107). It focuses on geohazards and slope 

stability using 100-kHz sidescan sonar, Huntec high- resolution and airgun seismics, and sampling as primary survey 

tools to be followed by a geotechnical program (Hart and 

others, 1991). 

Project PGC9105 was part of a continuing study of 

the surficial geology of the continental shelf of western 

Canada. Survey tools include piston corer, grab sampler, 

100-kHz sidescan sonar, and high-resolution and airgun 
single and channel reflection seismics. The results of this 

and related projects, as well as a reasonably complete 

bibliography of work done in the region can be found in 

Bomhold and Barrie (1991) and Barrie and others (1991). 

Project PGC91 02 is aimed at determining sediment 

dynamics (transport and failure) in fiords (Knight and Bute 

Inlets). The primary instrumentation for this study is a 

turbidity event detector (TED), which logs changes in 

suspended sediment concentrations in the water column 

(Bomhold and Prior, 1989). 

In response to this renewed interest in the nearshore 

and coastal zone, a variety of new tools and initiatives is 

being developed. These include a towed, transient electromagentic (TEM) system that is capable of measuring the 

electrical conductivity of the uppermost 5 m to 10 m of 

sediment of the sea floor (Cheeseman and others, 1987). 

The conductivities may be interpreted to give the porosity of 

the bottom sediments. This system has been successfully 

deployed in Knight Inlet (Cheeseman and others, 1991) and 

Queen Charlotte Sound. The system will be deployed on the 

Fraser Delta in 1992. 

To expedite the acquisition and analysis of data, PGC 

is participating with the Atlantic Geoscience Centre, Geological Survey of Canada, in a program to acquire contemporary marine hardware and software. The components of 

this program include (1) digital recording systems, (2) 

digital telemetry, (3) towfish positioning system, ( 4) 

co-registered sidescan and swath bathymetry system, (5) 

high-resolution multichannel seismic system, and (6) hardware and software for sidescan and seismic data processing 

enhancements. It is anticipated that these acquisitions will 

stimulate qualitative analyses of the data and result in more 

efficient techniques of sediment classification and interpretation. 

Substantial progress has been made in our knowledge 

and understanding of the geological component and processes present in the western Canadian offshore. It is 

anticipated that, over the next few years, the emphasis will 

be on site-specific, problem-oriented studies located primarily in coastal and nearshore zones. In the offshore, the 

focus will be on the deformation front-accretionary prism 

and the hydrothermal regime associated with Middle Valley 

and other parts of the Juan de Fuca Ridge. A remotely 

operated vehicle having a depth range of 3,000 m is under 

development and will be tested in research mode this 

summer with NOAA on the Juan de Fuca Ridge. Opportunities exist to more fully interpret and integrate the various 

data sets collected over the last two decades. Two projects 

of particular interest are ( 1) the magnetic data collected on 

ships of opportunity across a poorly surveyed region of the 

northeast Pacific (fig. 10) and (2) the deformation front off 

Vancouver Island (fig. 7, AMS 120 site), which has been 

surveyed with 6-, 12-, 30-, and 120-kHz sidescan sonars, as 

well as single and multichannel seismics systems. 

0 

0 

co 

lt) 

0 

N 

lt) 

co 

Nr-.-~--~-------T~~~~~~~~ 

~ 

0 

co 

Mr-----~~----~~WHffi4~~~-+--~ 

~ 

0 

~r-----~H-4+~~~Hh~---+--~--~ ~ 

.... 

0 

co 

co~--~~~-=~--~~----~------~ ~ 

Figure 10. Northeast Pacific tracklines, magnetics, and bathymetry only. 

Sea-Floor Mapping of the Western Canadian Exclusive Economic Zone 59 
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Atwater, T. , 1970, Implications of plate tectonics for the Cenozoic 

tectonic evolution of Western North America: Geological 

Society of America Bulletin, v. 81, p. 3513-3536. 

Atwater, T. , 1989, Plate tectonic history of the Northeast Pacific 

and Western North America, in Winter, E.L., Hussong, 

D.M., and Decker, R.E., eds., The Eastern Pacific Ocean 

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Barrie, J.V., Bomhold, B.D., Conway, K.W., and Luternauer, 

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Blackinton, J.G., Hussong, D.M., and Kosalos, J., 1983, First 

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Bomhold, B.D., 1980, Surficial sediments on the continental 

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---1982, Surficial sediments on the continental shelf, west 

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Bomhold, B.D. , and Barrie, J. V., 1991, Surficial sediments on 

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Research, v. 11, p. 685-699. 

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Cheeseman, S.J., Edwards, R.N., andChave, A.D., 1987, On the 

theory of sea-floor conductivity mapping using transient 

electromagnetic systems: Geophysics, v. 52, p. 204-217. 

Cheeseman, S.J., Law, L.K., and Edwards, R.N., 1991, Porosity 

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Davis, E.E., Chapman, D.S., Forster, C.B., and Villinger, H., 

1989, Heat-flow variations correlated with buried basement 

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Davis, E.E., Chapman, D.S., Mottl, M.J., Bentkowski, W.J., 

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1984, Juan de Fuca Ridge Atlas: SeaMARC II acoustic 

imagery: Earth Physics Branch, Open File 84-17. 

Davis E.E., Currie, R.G., and Sawyer, B.S., and Kosalos, J.G., 

1986, The use of swath bathymetric and acoustic image 

mapping tools in marine geoscience: Marine Technology 

Society Journal, v. 20, p. 17-27. 

Davis, E.E., Currie, R.G., Sawyer, B.S., and Riddihough, R.P. 

1985, Juan de Fuca Ridge Atlas: Regional SeaMARC II 

acoustic image mosaics and SeaBeam bathymetry: Geological Survey of Canada, Open File 1144. 

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across the northern Cascadia accretionary prism: Constraints 

from new heat flow and multichannel seismic reflection data: 

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Davis, E.E., Lister, C.R.B., Wade, U.S., and Hyndman, R.D., 

1980, Detailed heatflow measurements over the Juan de Fuca 

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299-310. 

Davis, E.E., Mottl, M.J., and Fisher, A., 1991~ Ocean Drilling 

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de Fuca Ridge: Ocean Drilling Program Preliminary Report 

No. 39, 55 p. 

Davis, E.E., and Seemann, D.A., 1981, A compilation of seismic 

reflection profiles across the continental margin of western 

Canada: Geological Survey of Canada, Open File 751. 

Dehler, S.A., and Clowes, R.M., 1988, The Queen Charlotte 

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1857-1890. 

Drew, J.J., and Clowes, R.M., 1990, A re-interpretation of the 

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---1987, Magnetic anomaly map of Canada (5th ed.): Geological Survey of Canada, Map 1255a, scale 1:5,000,000. 

---1990, Magnetic inclination, declination, and anomaly 

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Glen, F.M., 1970, Introducing an operational multi-beam array 

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Hart, B.S., Barrie, J.V., Currie, R.G., Luternauer, J.L. Prior, 

D.B., and MacDonald, R.D, 1991, High resolution seismic 

and side-scan sonar mapping of the Fraser Delta front and 

adjacent Strait of Georgia, British Columbia: Geological 

Survey of Canada Paper 91-1E, p. 19-23. 

Hey, R.N., and Wilson, D.S., 1982, Propagating rift explanation 

for the tectonic evolution of the Northeast Pacific-The 

pseudomovie: Earth and Planetary Science Letters, v. 58, p. 

167-188. 
Hyndman, R.D., and Davis, E.E., 1992, A mechanism for the 

formation of methane hydrate and seafloor bottom simulating 

reflectors by vertical fluid expulsion: Journal of Geophysical 

Research, v. 97, no. B5, p. 7025-7041. 

Hyndman, R.D., and Ellis, R.M., 1981, Queen Charlotte fault 

zone: microearthquakes from a temporary array of land 

stations and ocean bottom seismographs: Canadian Journal of 

Earth Sciences, v. 18, p. 776-788. 

Hyndman, R.D., and Rogers, G.C., 1981, Seismicity surveys 

with ocean bottom seismographs off western Canada: Journal 

of Geophysical Research, v. 86, p. 3867-3880. 

Hyndman, R.D., Yorath, C.J., Clowes, R.M. and Davis, E.E., 

1990, The northern Cascadia subduction zone of Vancouver 

Island: seismic structure and tectonic history: Canadian Journal of Earth Sciences, v. 27, p. 313-329. 

Laughton, A.S., 1981, The first decade of GLORIA: Journal of 

Geophysical Research, v. 86, p. 11511-11534. 

Mackie, D.J., Clowes, R.M., Dehler, S.A., Ellis, R.M., and 

Morel-a-l'Hussier, P. 1989, The Queen Charlotte Islands 

Refraction Project: Part II-Structural model for transition 

from Pacific plate to North American plate: Canadian Journal 

of Earth Sciences, v. 26, p. 1713-1725. 

Malahoff, A., Hammond, S.R., Embley, R.W., Currie, R.G., 

Davis, E.E., Riddihough, R.P., and Sawyer, B.S., 1985, 

Juan de Fuca Ridge Atlas: Preliminary SEABEAM bathymetry: Geological Survey of Canada, Open File 1143, 23 

maps. 

Nobes, D.C., Law, L.K., and Edwards, R.N., 1986, The determination of resistivity and porosity of the sediment and 

fractured basalt layer near the Juan de Fuca Ridge: Geophysical Journal of the Royal Astronomical Society, v. 86, p. 

289-317. 

Riddihough, R. P., 1984, Recent movements of the Juan de Fuca 

plate system: Journal of Geophysical Research, v. 89, p. 

6980-6994. 

Riddihough, R.P., and Hyndman, R., 1989, Queen Charlotte 

Islands margin, in Winter, E.L., Hussond, D.M., and 

Decker, R.E., eds., The Eastern Pacific Ocean and Hawaii, 

The Geology of North America: Geological Society of 

America, Boulder, Colo. 

Rohr, K.M.M., and Dietrich, J.R., 1990, Deep seismic reflection 

survey of the Queen Charlotte Basin, British Columbia, in 

Evolution and hydrocarbon potential of the Queen Charlotte 

Basin, British Columbia: Geological Survey of Canada Paper 

90-10, p. 127-133. 

Rohr, K.M.M., Milkereit, B., and Yorath, C.J., 1988, Asymmetric deep crustal structure across the Juan de Fuca Ridge: 

Geology, v. 16, p. 533-537. 

Speiss, F.N., and Tyee, R.C., 1973, Marine physical laboratory 

deep tow instrumentation system: Scripps Institute of Oceanography, ref. 73--4. 

Spence, G.D., Clowes, R.M., and Ellis, R.M., 1985, Seismic 

structure across the active subduction zone of western Canada: Journal of Geophysical Research, v. 90, p. 6754-6772. 

Spence, G.D., Hole, J.A., Asudel, 1., Ellis, R.M., Clowes, 

R.M., Yuan, T., and Rohr, K.M.M., 1990, A seismic 

refraction study in the Queen Charlotte Basin, British Columbia, in Evolution and hydrocarbon potential of the Queen 

Charlotte Basin, British Columbia: Geological Survey of 

Canada Paper 90-10, p. 135-149. 

Sweeney, J.F., and Seemann, D.A., 1990, Crustal density structure of Queen Charlotte Islands and Hecate Strait, British 

Columbia, in Evolution and hydrocarbon potential of the 

Queen Charlotte Basin, British Columbia: Geological Survey 

of Canada Paper 90-10, p. 89-86. 

Wahlstrom, R., and Rogers, G.C., 1990, Relocation of earthquakes offshore Vancouver Island: Geological Survey of 

Canada, Open File 2288. 

White, D.J., and Clowes, R.M., 1990, Shallow crustal structure 

beneath the Juan de Fuca Ridge from 2-D seismic refraction 

tomography: Geophysical Journal International, v. 100, p. 

349-367. 

Sea-floor Mapping of the Western Canadian Exclusive Economic Zone 61 
Scripps Institution's Multibeam and Magnetic Mapping 

West of California and Baja California 

Peter Lonsdale 

Scripps Institution of Oceanography 

Abstract 

For the past 10 yr, the Scripps Institution has operated a SeaBeam-equipped ship from its San Diego base, 

mostly on long-range cruises to remote areas of the Pacific 

and South Atlantic. A substantial volume of data has also 

been collected on transits to and from home port and 

during a few special survey cruises within the United 

States and Mexican Exclusive Economic Zone off southern 

California and Baja California. The oceanic crust in these 

regions was accreted 30-40 m.y. ago as part of the East 

Pacific Rise that was colliding with the North American 

62 Proceedings, 1991 EEZ Symposium on Mapping and Research 

continent and breaking up into complex patterns. Joint 

analysis of multibeam bathymetry and magnetic lineations 

has proven essential for untangling this structural complexity and for identifying "fossil" spreading centers, 

transform faults, and trenches that still exist offshore. We 

have devoted less effort to the region west of central and 

northern California where bathymetry is much less informative because thick sediment deposits have smothered 

the oceanic crust. In 1992, we will commence operations 

with a much more powerful SeaBeam 2000 mapping sonar, 

and some of the early cruises with this new system are 

scheduled for local waters. 
Deep-Towed Swath Bathymetry by an Interferometric 

lsophase Method 

Arthur St. C. Wright 

Williamson & Associates, Inc. 

Abstract 

The interaction of receiver patterns from separated 

parallel sidescan sonar transducers produces an isophase 

fringe pattern from which swath bathymetry can be calculated. The theory, basic configuration, and operational 

techniques for deep-towed bathymetry by a fringe or 

isophase method are reviewed. Examples of data are 

shown, and processing techniques addressed. A comparison with other methods is discussed. 

INTRODUCTION 

The hydrographer or ocean engineer who is interested 

in gathering swath bathymetric data in the deep ocean has a 

choice of three basic types of systems to employ: hullmounted sidelooking sonar systems, shallow-towed sidescan phase-difference measuring systems, and deep-towed 

sidescan interferometric isophase systems. The summary of 

deep-ocean swath bathymetry systems shown in table 1 

traces the development of the three primary types of 

systems. The first hull-mounted multibeam system, the 

Sonar Array Sounding System (SASS) is a classified system 

developed in 1964 by the General Instrument Corporation 

(GIC) and installed in several Navy ships. This was 

followed by another classified system known as Narrow 

Beam Echo Sounder (NBES), which was installed in nine 

U.S. Navy (USN) and National Oceanic and Atmospheric 

Administration (NOAA) research vessels. In 1977, concomitant with advances in realtime computing and datastorage technology, GIC introduced a commercial system, 

SeaBeam, which was installed on 18 oceanographic 

research vessels of the United States, Australia, France, 

West Germany, and Japan. The newest SeaBeam system is 

the SeaBeam 2000, which is a modular unit providing 

flexibility of design in hardware and software to suit the 

customer (General Instrument Corporation, 1990). Development of multibeam sonars in the United States was 

quickly followed by German, Finnish, Japanese, and Norwegian systems as shown in table 1. Today, there are more 

than 70 ships having multibeam systems. In general, these 

systems consist of a number of discrete transducers that 

project from 16 to > 100 discrete mechanical or electronic 

beams having a known declination angle that is used to 

compute slant range information. In deep water, these 

systems are subject to large footprint generalizations, raypath ambiguities and sea-state problems, but they do provide a means of rapidly surveying large areas. Recent 

advances in electronic beam forming and digital signal 

processing are providing significant improvements to this 

type system (Congress of the United States Office of 

Technology Assessment, 1987; de Moustier, 1988; and 

Satriano and Geneva, 1991). 

Table 1. Swath bathymetry systems 

System Designer/Mfg!Operator Year 

Multibeam (over 1,000 m depth capability) 

Sonar Array Sounding Sys. General Instrument Corp. 1964 

SeaBeam General Instrument Corp. 1977 

Hydrosweep Krupp Atlas; W.Ger. 1986 

Ekhos-15/625 Hollming; USSR 1985 

Ekhos XD Hollming; Finland 1987 

MBSS JRC; Japan 1988 

SeaBeam 2000 SeaBeam Instruments Inc. 1990 

EM12 Simrad/Ifremer 1990 

Interferometric-Phase Angle 

BASS Denbigh; UK 1979 

TOPO-SSS IKU, Norway 1982 

SeaMARC II IST/HIG 1983 

SeaMARC S IST/SSI 1986 

Bathyscan 300 Bathymetrics, Ltd; UK 1986 

Izanagi SSI/Univ. of Tokyo 1987 

Sys120 SSI 1988 

AMS-120SP AMS/WHOI 1989 

Sys09 SSI 1990 

Interferometric-Isophase 

Telesounder Stubbs and others; UK 1974 

ISSS Univ. of Hannover, FRG 1982 

Side Looking Phase Sonar Aleksandrov and others; USSR 1983 

SeaMARC CLX IDSS/Williamson & Assoc. 1988 

AMS-120SI AMS/IDSS/Williamson 1989 

Deep-Towed Swath Bathymetry by an Interferometric lsophase Method 63 
The towed "phase difference measuring" and 

"isophase" or "fringe" interferometric systems are both 

descended from the Telesounder that was developed in the 

United Kingdom in 1973. This sonar was based on a Lloyds 

Mirror principle that produced fringes as a result of interference developed by sea-surface reflections and the transmit beam at discrete declination angles from which slant 

ranges and depths could be computed. "Interferometry" was 

originally an optics term pertaining to the study and precise 

measurement of small dimensions, density, and other properties of substances by means of the interference patterns of 

two rays of light. In acoustics, the term "interferometry" is 

widely used to encompass any measurements gathered with 

an interferometer, a sonar that has two closely spaced 

receivers, one above the other. In the literature on interferometric swath bathymetry systems, there are several different nomenclature conventions; this paper will use "phase 

difference measuring" and "isophase" to refer to the two 

types. In discussing the merits of surveying systems, the 

terms "resolution," "accuracy," and "precision" are frequently used interchangeably. In this paper, the convention 

adopted by Blackinton will be followed: resolution refers to 

the smallest change or dimension that can be measured; 

accuracy refers to the ability to make measurements that 

agree with measurements made by other techniques, and 

precision refers to the ability to make repeated measurements with similar results (Blackinton, 1991). 

The accuracy, resolution, and precision of bathymetry information from the two towed systems are affected 

variously by the size of the acoustic beam foot print, the 

sound velocity profile between the sonar device and the sea 

floor, the degree of multi path interference caused by seafloor roughness, and the capabilities of the navigation and 

towfish positioning systems used in collecting the data. In 

general, the shallow-towed phase-angle systems are towed 

at higher speed, and yield wider swath coverage, but data 

are of less resolution and accuracy; the deep-towed isophase 

systems produce smaller swath coverage but more resolution and accuracy. For general exploration, the shallowtowed systems provide sufficient resolution, whereas for a 

site-specific engineering survey, the deep-towed method is 

frequently specified. Resolution of deep-towed method is 

higher because of proximity to the seafloor; accuracy and 

precision are better due to less error from multipath and 

velocity profile effects; processing time is faster, and 

problem areas are easily identifiable. 

The phase-difference measuring systems compute the 

angle of the returning sea-floor backscatter at increasing 

time intervals by comparing the phase angles at two 

receivers as shown in figure 1. The first system, the 

Bathymetric Sidescan Sonar (BASS) was developed by 

Denbigh at the University of Birmingham in 1979 (Denbigh, 1989). Commercial systems in use today are produced 

by Seafloor Surveys International and Acoustic Marine 

64 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Figure 1. Phase-difference measuring swath bathymetry. 

The returning signal is sampled at each instant, and the 

angle of the returning backscatter from the sea floor is 

determined by comparing the phase at an interferometer. 

The swath depths are computed using the slant ranges 

associated with each angle. 

Systems, both of Seattle, Wash., and Bathymetrics Ltd. in 

the United Kingdom. 

The isophase systems establish an interference fringe 

pattern with either the transmit beams or the receive beams 

using interferometers and calculate ranges to these fringes, 

which can be converted to crosstrack bathymetry information that is a function of the declination angle of the beam 

and the depth of the towfish. Experimental systems were 

fielded by the Soviets and the Germans in the early 1980's, 

and Williamson & Associates, Inc., of Seattle developed 

the first commercial system in 1988 (Lesnikowski, 1989). 

FUNDAMENTALS OF ISOPHASE 

I NTERFEROMENTRY 

An acoustic interferometer consists of two arrays 

mounted in the same plane, one above the other as shown in 

figure 2. Sidescan sonar signals returning from the sea floor 

will be in phase at discrete angles off the perpendicular to 

the array. The magnitude of these angles is dependent on 

the distance between the arrays and the wavelength of the 

returning signal. At each angle where the signals received 

are in phase, the signals are reinforced, and a fringe will be 

generated as the towfish moves over the sea floor. This 

fringe represents a constant phase and is therefore an 

isophase line. The number of fringes that could theoretically 

be developed to one side of the perpendicular of an 

interferometer face is equal to the separation distance of the 

two arrays in wavelengths. Figure 3 depicts the calculation 

of angles for an interferometer with a separation distance 

between arrays of four wavelengths. Figure 4 shows the 

method of calculating the depths across the swath. In 

practice, fringe angles are developed on both sides of the 

perpendicular to the arrays, and the addition of another 

interferometer on the other side of the towfish provides full 

swath coverage. The distance between crosstrack depths 
1% = Arccos ~ where n = number of wavelengths out of phase. 

D 

Figure 2. Plane wave approaching a two-element interferometer with separation distance D between elements. As 

the range along the sea floor increases, the angle {tn 

between the perpendicular to the array face and the 

direction of wave propagation changes. 

can be adjusted by altering towfish height or sonar frequency. The number of fringes is changed by altering 

element spacing or adding additional interferometers. A 

typical set of fringes is shown in figure 5. The digital record 

of these data provides both maxima and minima outward 

along each ping, which are easily detectable by a computer 

algorithm. Widening of the fringes, as range increases, is 

due to increased sampling time with range in the digitization 

process so that crosstrack pixel size will remain constant. 

The record in figure 6 depicts a rough sea floor where 

fringes come together and actually cross. This is indicative 

of a decreasing slant range and a steep face on the 

topography and marks this area as one that will require 

careful postprocessing. 

APPLICATIONS 

As offshore oil development, cable laying, pipeline 

siting and installation, ocean mining, offshore sensor installation, disposal site identification, and other engineering 

projects occur in progressively deeper water, techniques to 

obtain requisite data on geotechnical and engineering 

parameters must be optimized for suitability and effectiveness. The majority of bathymetric information currently 

available concerning the sea floor is not suitable for 

engineering purposes because it is insufficiently accurate in 

position or depth. The advent of more sophisticated differential Global Positioning System (GPS) positioning equipment that allows extremely accurate geodetic-positioning 

measurements and depth-measuring equipment with resolutions that allow depths to be measured to 0. 1 percent of total 

depth has created demands by the engineering community 

n = 0 

&=0 

n=2 

fu = Arccos 2/4 

fu = 60 degrees 

n=1 

fr1 = Arccos 1 I 4 

fr1 = 75 degrees 

~ 

I I\\ 

n=3 

fr3 ·Arccos 3/4 

fr3 • 41.4 degrees 

n = number of wavelengths out of phase between 

interferometer elements. 

Figure 3. Plane waves approaching an interferometer with 

n equaling 0, 1, 2, and 3. At each of the angle {ts for these 

cases a fringe will occur. 

Figure 4. Range to sea floor at fringes. 

Deep-Towed Swath Bathymetry by an Interferometric lsophase Method 65 
Figure 5. A typical starboard fringe as recorded on a graphic recorde~. The_ towfish track _is t?wards the ri~ht. ~he 

widening of the fringe at increasing ranges is due to increased sampling t1me w1th range to mamtam a constant p1xel s1ze 

in the digitization process. 

for the best data available. As opposed to earlier depth 

sounders, which only measured directly under the ship, 

contemporary sidescan sonars operated in a swath bathymetry mode can measure accurately across a swath along the 

ship track. This information is combined with sidescan 

imagery, navigation, and other geophysical data to support 

engineering decisions. A hull-mounted or surface-towed 

system provides adequate data considering that readings 

from precision depth recorders or other surface systems are 

biased to the uphill side of a large footprint, that the spatial 

averaging of rough terrain causes the sea floor to appear 

more smooth chan it actually is, and that a varying velocity 

profile can result in an incorrect depth, for general exploratory surveys of the sea floor and identification of general 

features. However, if a cable, pipeline, template, or other 

installation is to be sited, the most accurate and precise data 

available must be gathered and utilized for responsible 

decisionmaking (Williamson, 1988). 

66 Proceedings, 1991 EEZ Symposium on Mapping and Research 

EQUIPMENT 

The only commercial firm currently using the 

isophase technique in deep water is Williamson & Associates, Inc., of Seattle, Wash. Williamson has had one 150-

and two 120-kHz sonars converted for collecting isophase 

bathymetry. These are the 1st CLX and the AMS-120SI 

(fig. 7). The CLX was converted to an interferometric 

system by shifting the port array to the starboard side and 

summing the results. The AMS 120's were designed and 

built with a simultaneous interferometric and sidescan 

imaging capability to each side. Both the CLX and the 

AMS-120 are towed 50 m to 100 m above the sea floor 

behind a I ,800 lb depressor, which reduces vessel motion 

effects. The towfish also provides a capability for subbottom profiling; magnetometry; and pitch, heading, and roll 

sensors and a transponder for long baseline positioning. The 

information is processed topside in Triton Technology, Inc. 

QMIPS image processors. 
Figure 6. Photograph of a set of fringes from a video monitor. The towfish track is toward the top of the picture. A fringe 

tracking cursor has been activated halfway up the port image for four of the fringes. On the starboard side near the 

bottom, the fringes merge indicating steep topography and an area for additional attention. 

In all towfish swath bathymetry schemes, towfish 

depth is a key factor in the calculations, as total water depth 

is the sum of the depth of the towfish from the sea surface 

plus the vertical distance between the horizontal plane of the 

towfish and the crosstrack (swath) points on the sea floor. 

The best depth sensors are thermally calibrated quartz 

crystal systems that are integrated into the system circuitry 

and that transmit a depth up the cable with every ping. The 

accuracy of these systems, when properly calibrated, is less 

than 0.01 percent of depth or less than a meter at full ocean 

depth. In some of the acoustic long-baseline systems, which 

have pressure sensors in the individual computing transducers, towfish depth is calculated as part of the towfish 

positioning solution. In any case, whatever the objective of 

the survey, the depth of the towfish must be known. 

Sidescan sonar systems used for engineering surveys 

must have an accurate towfish positioning system integrated 

Figure 7. Front view of AMS-120 sidescan sonar. The two 

starboard arrays can be seen above the starboard skid. 

Deep-Towed Swath Bathymetry by an Interferometric lsophase Method 67 
with the data collection system. An engineering survey 

requires towfish position and attitude to be recorded with 

each ping as opposed to a search where accurate positioning 

is required only to ensure that no gaps are left in the search 

plan and that towfish lay back derived from ship's position 

and the amount of cable out and towfish depth are acceptable. The resolution and accuracy requirements for the 

siting of the Exxon Heritage Platform in 1 ,075 ft of water in 

Santa Barbara Channel in 1989 were ± 1 ft in depth and 7 ft 

in position (Siciliano and others, 1991). For sidescan sonar 

systems in which the tow cable length is less than about 

1,500 m, an acoustic ultrashort- (also known as supershort) 

baseline system can provide adequate position data to an 

accuracy of approximately 1 percent of slant range. This 

accuracy is affected by sea state, tracking transducer mounting position on the ship, towfish speed, and sound velocity 

profile. For a deep-towed area search where longer cable 

lengths are used, an acoustic long-baseline system is 

employed consisting of a precisely calibrated net of from 4 

to 20 or more acoustic transponders on the sea floor. If the 

tracking transducer is mounted on the towfish, then the ship 

is out of the problem, and the towfish position relative to the 

transponder net is sent to the surface with the results of each 

ping (Kelland, 1989). In a long-route operation such as a 

deep-towed cable route survey where a long-baseline system is impractical, and where the range to the towfish is 

excessive for an ultrashort system, it is necessary to 

combine a hull-mounted multibeam swath bathymetry system with the deep system in order to position the towfish. In 

this case, towfish positioning can be determined by interactive comparison with the multibeam contour information 

(Malinvemo and others, 1990). 

PROCEDURE 

Development of procedures for gathering and processing isophase swath bathymetry data has evolved over 

time as new and improved equipment and data processing 

schemes became available. In general, the following steps 

are followed: 

• Calibrate system and confirm declination angles to each 

fringe (reinforcing maximum or null minimum) in the 

survey area. 

• Collect bathymetry data on desired swath, altitude, and 

overlap. 

• Smooth navigation data. 

• Run computer routine to correct slant ranges for heading 

and roll data and to convert to offtrack depths. Annotate 

areas where fringes cross or run together so these can be 

given additional attention later. 

• Plot track with depth data and compare with bathymetry 

data from other tracks. 

• Make crosstrack runs to verify data, when primary tracks 

are complete. 

68 Proceedings, 1991 EEZ Symposium on Mapping and Research 

• Make additional runs to fill in any gaps, to doublecheck 

inconsistent data, and to collect data in rough terrain. 

• Select gridding criteria and contour parameters. 

• Correct for tidal variation; ensure sound velocity profile 

control. 

• Plot contour and three-dimensional maps and charts. 

These steps assume near-perfect towfish positioning 

data that are integrated with the swath bathymetry data 

during the runs and a constant sound velocity. If it is 

necessary to postprocess the navigation data, the possibility 

for error increases and at-sea production of correct maps 

and charts is not possible. In this case, all runs are made 

with the best navigation available, and bathymetry processing occurs after the survey. If there are variations in the 

sound velocity during the survey, declination angles to the 

fringes will vary, and adjacent and crosstrack data affected 

will not match; postprocessing is necessary to correct the 

data set. 

RESULTS 

The isophase systems have been on six commercial 

surveys and two Government surveys as shown in table 2. 

The first survey for Exxon in the Santa Barbara Channel 

employed the SeaMARC CLX, and the other surveys have 

all employed the AMS-120. In all cases, the resolution, 

accuracy, and precision of the system have met the requirements of the survey. On two occasions where petroleum 

industry structures were sited using isophase bathymetry 

data, the survey depths were within 6 in of the static 

mechanical measurement. 

CONCLUSION 

As a tool for the hydrographer and the oceanographic 

engineer, the isophase interferometric system has a clear 

niche as a surveying tool. It provides rapid and accurate 

data quickly and simply. The system can be used off ships 

of opportunity, and the information can be passed up long 

Table 2. Results of isophase surveys 

Major Area Type 

Area client Date covered survey 

Santa Barbara Channel Exxon Aug 88 110 km2 Pipeline. 

Santa Barbara Channel Exxon Aug 89 2 km2 Siting. 

Gulf of Mexico Exxon May 90 155 km2 Pipeline. 

Puget Sound Draper Lab Jul90 8 km2 R&D. 

West coast of Scotland BP Jul90 50 km2 Hazard. 

Strait of Georgia Navy Sep 90 41 km2 General. 

Northeast Coast AT&T Jun 91 380 km2 Cable. 

Continental Shelf. 

Gulf of Mexico Ensearch Oct 91 600 km2 Pipeline 

towout. 
cables without loss of data. If there are areas with irregular 

and steep sea-floor terrain, the raw data will highlight the 

magnitude and areal extent of the problem. The physics 

involved are straightforward, and the results are achieved 

by simple addition of two received signal values; sophisticated schemes to determine a slight change in a phase angle 

are not necessary. Current growing pains in the isophase 

technique are being rapidly resolved by advances in computer storage capability and digital signal processing. As in 

any survey, navigation must always be carefully addressed. 

REFERENCES CITED 

Blackinton, J.G., 1991, Bathymetric resolution, precision and 

accuracy considerations for swath bathymetry mapping sonar 

systems: Proceedings of the Institute of Electrical and Electronics Engineers Oceans '91 Conference, v. 2, p. 550-557. 

Congress of the United States Office of Technology Assessment, 

1987, Marine minerals-Exploring our new ocean frontier: 

Washington, D.C., U.S. Government Printing Office. 

de Moustier, C., 1988, State of the art in swath bathymetry survey 

systems: International Hydrographic Review, LXV(2). 

Denbigh, P.N., 1989, Swath bathymetry-Principles of operation 

and an analysis of errors: Institute of Electrical and Electronics Engineers Journal of Oceanic Engineering, v. 14, no. 4. 

General Instrument Corporation, 1990, SeaBeam 2000, A family 

of systems for bathymetric swath survey, Brochure. 

Kelland, N.C., 1989, Accurate acoustic positioning of deep 

deepwater geophysical towfish: 20th Offshore Technology 

Conference in Houston, Texas, and Hydrographic Journal, 

no. 51. 

Lesnikowski, N., 1989, Deep towed interferometric swath 

bathymetry: Proceedings of the Marine Technology SocietyInstitute of Electrical and Electronics Engineers Oceans '89 

Conference, v. 4, p. 1130-1133. 

Malinvemo, A., Edwards, M.H., and Ryan, W.B.F., 1990, 

Processing of SeaMARC Swath Data, Institute of Electrical 

and Electronics Engineering Journal of Oceanic Engineering, 

v. 15, no. 1. 

Satriano, J.H., and Geneva, A., 1991, Wide swath bathymetry 

from multi beam sonar systems: Proceedings of the Institute of 

Electrical and Electronics Engineers Oceans '91 Conference, 

v. 2, p. 733-736. 

Siciliano and others, 1991, Site location survey for the heritage 

platform: Proceedings of the Offshore Technology Conference, Houston, Texas, Paper no. 6690. 

Williamson, M.E., 1988, Application of wide-swath, deeply 

towed bottom imaging sonar in geotechnical evaluation of the 

sea floor: Current Practices and New Technology in Ocean 

Engineering, v. 13 (by American Society of Mechanical 

Engineers). 

Deep-Towed Swath Bathymetry by an Interferometric lsophase Method 69 
Oregon's Ocean Plan, an Emerging State Ocean Program 

and Information Needs 

D. Eldon Hout 

Oregon Department of Land Conservation and Development 

Abstract 

The State of Oregon, one of several coastal States 

addressing ocean resources through its coastal management program, recently adopted the Oregon Ocean 

Resources Management Plan. Legislation requiring the 

Ocean Plan set a State policy of co-management with 

Federal Agencies for ocean resources within the Exclusive 

Economic Zone and recognized the need for additional 

ocean information for management. Oregon is developing a computerized ocean information system for storing 

and using ocean resource information. The Ocean Plan, 

70 Proceedings, 1991 EEZ Symposium on Mapping and Research 

adopted after lengthy public involvement, includes policies for a variety of ocean resources and uses across the 

continental shelf off Oregon. Throughout, the Plan identifies numerous information needs about ocean resources, features, and conditions and outlines a general 

hierarchy for information acquisition. However, it appears 

that information needed for most ocean management 

decisions focuses on more "fine-grained" nearshore areas 

and resources in contrast with the broad-scale, deep-ocean 

approach of existing Federal Exclusive Economic Zone 

research programs. 
Resource Potential of Offshore Placer Deposits 

Clifford E. McClain 

Consultant 

Abstract 

The resource potential of offshore placer deposits 

has a long ristory on the Pacific coast, particularly in 

Northern California, Oregon, and Alaska. Gold mining 

commenced in the latter half of the 19th century and 

continues in some parts today, most recently the WestGold operation at Nome, Alaska. Principal economic minerals include gold and platinum group metals, chromite, 

ilmenite, rutile, and zircon-the potential commercial 

value of which may be very large. Basic exploration data 

exist, but deposits have generally not been well characterized. Prospects for commercial development are significantly limited by the minerals market and by coastal 

resource management and environmental considerations. 

Within these constraints, near-term commercial development seems unlikely, other than very limited operations 

such as that of WestGold. The long-term resource potential of these vast deposits, however, seems undeniable. A 

new factor is the potential which these deposits may 

represent for a "strategic reserve" against future national 

security requirements, as a base for future national economic stability in a vigorous, competitive, and uncertain 

world socioeconomic environment, rather than for military mobilization. 

Resource Potential of Offshore Placer Deposits 71 
A Case Study of the Norton Sound Alaska Marine Mineral 

Lease Sale Process 

Anthony C. Giordano 

Minerals Management Service 

Abstract 

This paper discusses the planning and results of the 

first offshore gold placer lease sale ever held in Federal 

waters. In March and June 1991, respectively, the Minerals 

Management Service published the final Environmental 

Impact Statement and the Final Notice of Sale for a Federal 

offshore mineral lease sale in Alaska's Norton Sound. The 

sale area was adjacent to a recently mined offshore area in 

State waters and upland areas having a long mining 

history. The sale area focused on acreage that has the 

highest potential for placer gold and covered 34 whole 

and partial blocks encompassing about 147,000 acres. The 

final EIS estimated the area's recoverable gold to range 

from 530,050 troy ounces (mean case) to 1,060,000 troy 

ounces (high case). The area is located between 3 mi and 

14 mi offshore Nome in water depths ranging from 66ft to 

99ft. 

The Notice of Sale outlined the terms and conditions 

of the sale and contained restrictions on the operations in 

the form of stipulations and Information to Lessees 

clauses. Restrictions provided environmental protection 

and responded to concerns expressed during the prelease 

process. The Environmental Impact Statement and other 

administrative steps leading to this sale were accomplished through a unique cooperative agreement and 

Coordination Team effort with the State of Alaska and 

local interest groups. The lease sale was scheduled for July 

24, 1991. No bids were received, and a sale did not occur. 

Several companies were contacted and requested to 

provide some insight as to why no bids were submitted. 

Various reasons were given including low gold prices, 

limited availability of mining vessels, lowest point of price 

curve swing, difficulty in obtaining capital financing, better opportunities in State waters, and legal uncertainty. 

INTRODUCTION 

Over 5 million ounces of gold were recovered from 

onshore placer deposits in the greater Nome district since 

1898 when gold was discovered at Anvil Creek. Deposits 

occurred primarily as glacial-fluvial and glacial-marine 

72 Proceedings, 1991 EEZ Symposium on Mapping and Research 

placers associated with strandline deposits, such as the 

modem beaches at N orne or the elevated ancient beaches 

located further inland (Nelson and Hopkins, 1972). Gold 

was initially eroded from lode deposits on the Seward 

Peninsula and reworked by fluvial, glacial, and marine 

processes. Subsequent to deposition, enrichment factors 

such as marine scour and fluvial erosion reworked the 

Pleistocene-age glacial material. 

From 1985 to 1990, gold placers were extracted from 

State waters within the area covered by the glacial deposits. 

Western Gold Exploration and Mining Company, Limited 

Partnership (WestGold), conducted mining activities on part 

of their 21 ,750-acre leasehold offshore Nome. WestGold 

verified the existence of the deposit and proved the viability 

of conducting mining operations within the State 3-mi zone. 

Over 100,000 ounces of gold were recovered by the mining 

vessel Bima from 1986 to 1990. 

WestGold' s successful operations provided the stimulus to offer for lease submerged Federal lands in the 

Norton Sound in the vicinity of Nome, Alaska, for mining 

and recovery of gold and any associated minerals. Because 

offshore mining of gold placer deposits was presently 

occurring in State waters in Norton Sound, the State of 

Alaska expressed the need to evaluate the feasibility of 

developing mineral resources and developing technical 

guidelines and procedures for safe, effective, and environmentally sound exploration and mining of mineral resources 

on the Outer Continental Shelf (OCS). In order to provide a 

complete record of events leading to the sale, this paper 

addresses the planning and results of the first offshore gold 

placer lease sale offered in Federal waters. 

RESOURCE POTENTIAL 

In the Federal OCS, submerged beach ridges occur on 

the sea bottom at depths of 21, 24, and 27 m (U.S. 

Department of the Interior, 1987). Buried ancient channels 

are also recognizable on seismic profiles. Because subsurface samples from the OCS are sparse, little resource 
information exists for gold deposits in Federal waters. 

However, these geomorphic features are potential targets in 

the sale area. On the basis of the available data, the highest 

potential blocks in the proposed sale area may be those 

closest to the gold-bearing glacial deposits offshore Nome. 

The glacial deposits appear to straddle the Federal-State 

boundary. The final Environmental Impact Statement (EIS) 

estimated recoverable gold ranges from 530,050 troy 

ounces (mean case) to 1,060,000 troy ounces (high case) in 

the sale area. Because of W estGold' s early success in 

mining gold placers in State waters, the acquisition of more 

leases was a logical next step. 

COORDINATION TEAM 

In November 1987, WestGold (formally Inspiration 

Gold, Inc.) wrote to the Department of the Interior (DOl) to 

request that a lease sale be held for gold mining in Federal 

waters near Nome, Alaska. In the same month, the State of 

Alaska requested a cooperative agreement with the Minerals 

Management Service (MMS) to establish a joint FederalState task force. The Governor requested in his letter to the 

Secretary of the Interior that a task force be established to 

... evaluate the feasibility of development of mineral 

resources adjacent to the coast and to develop safe 

technical guidelines and procedures for the safe, 

effective, and environmentally sound exploration and 

mining of the resources. The task force should also 

review the economic feasibility and look at the needs 

for Environmental Impact Statement (EIS) development and to identify renewable and non-renewable 

resources that are present in the Norton Sound and 

possible use conflicts. 

In response to the Governor's letter, the Secretary (DOl) 

agreed to establish a joint Federal-State task force and to 

designate the Director of MMS to implement the program. 

The joint Federal-State task force was later organized 

into the 31-member Coordination Team (CT) that was 

established in February 1988. From its inception, the CT 

was envisioned as a forum for the exchange of information 

and expertise and to consult on decisions leading to the 

lease sale. The CT was integrated into all major steps of the 

decision process, including scoping, review of the first draft 

EIS, public hearings, two workshops, second draft EIS, 

final EIS, and the draft and final Notice of Sale. The CT 

organization consisted of two co-chairmen, one appointed 

by the Secretary of the Interior and one appointed by the 

Governor of Alaska. A coordinator was designated by 

MMS and the State to facilitate the exchange of information 

and the planning or scheduling of CT activities. The CT 

process worked extremely well in maintaining communication throughout the prelease process by highlighting important issues early, stimulating constructive dialogue between 

parties, and promoting timely resolution of sensitive issues. 

MMS and the State believe that the CT process provided the 

mechanism to successfully complete all the necessary 

administrative steps leading to the sale. 

PRELEASE PROCESS 

A Request for Comments and Nominations was 

issued on March 11, 1988. This request concerned an area 

covering approximately 77 blocks encompassing some 

350,000 acres. Three companies responded to the request. 

The Area Identification was announced on May 27, 1988, 

and covered some 40 blocks totaling about 178,000 acres to 

be analyzed in the EIS. This area was identified from the 

evaluation of comments received from the request and 

results of the scoping process. Central issues cited pertain to 

the effects of mercury and other trace metals on water 

quality, marine biota, fuel spills, and subsistence resources 

and to operations in severe weather conditions and consistency with the Alaska Coastal Management Program. 

FIRST DRAFT ENVIRONMENTAL IMPACT 

STATEMENT 

On November 23, 1988, the first draft EIS was issued 

(U.S. Department of the Interior, 1988). Based on available 

data, major impacts from the proposal were anticipated on 

water quality, commercial fisheries, subsistence harvest 

patterns, and sociocultural systems. The proposal did not 

include stipulations or Information to Lessees (ITL) clauses 

specifically designed to mitigate adverse effects for any 

mining operation. In January 1989, a public hearing was 

held in Nome on the first draft EIS. Federal, State, and local 

government agencies, as well as members of the public, 

expressed concern that the information used for the first 

draft EIS was inadequate for proper analysis and reasoned 

decisions. Lack of information was of concern in the 

following subject areas: the actual level of mercury in the 

food chain; levels of mercury in humans; and the effect of 

dredging on benthic habitats, particularly for red king crab. 

The MMS initiated studies to obtain information on these 

subjects, both through field research and assistance from 

subject-matter experts during two public workshops. In 

September 1989, a decision was made to prepare a second 

draft EIS using new information on water quality and 

trace-metal analysis in human hair. 

MITIGATION 

Through extensive review by the MMS, the Environmental Protection Agency (EPA), Federal public health 

agencies, the Fish and Wildlife Service, and various other 

A Case Study of the Norton Sound Alaska Marine Mineral Lease Sale Process 73 
Federal and State agencies, including comments from the CT 

and the public, mitigation measures were formulated that 

MMS believed would adequately protect environmental 

resources. There could be a potential risk of adverse effects 

to the environment if the areas proposed for offering were 

explored and developed. The risk would be related to 

environmental effects that could result from the mining, 

transportation, and metallurgical processing operations of a 

mining industry. Socioeconomic effects from onshore activities of this industry could have local and (or) State implications. The stipulations that were developed by MMS to 

reduce the type, occurrence, and extent of adverse effects 

associated with the proposal are listed below. 

Environmental Survey and Monitoring Program and 

Operations Management.-This stipulation required lessees (1) to conduct environmental surveys that addressed 

water quality, certain trace metals, and the presence, 

distribution, and composition of biological communities, 

including marine mammals and red king crabs and (2) to 

identify existing conditions and any trends or changes 

resulting from mining activities. 

Prohibition of Use of Mercury or Other Toxic Substances in Processing. -This stipulation prohibited use or 

storage of mercury or any other toxic substance for testing 

and (or) beneficiation of placer minerals onboard dredging 

or other vessels. 

Baseline and Monitoring Studies on Mercury Levels 

in Humans.-This stipulation required lessees to monitor 

mercury levels in the Nome population (1) if baseline 

information collected by the MMS or other Federal, State, 

or regional health agencies indicated potential human health 

problems according to World Health Organization safety 

standards and (2) if site-specific environmental survey and 

monitoring or other information indicated lease activities 

may contribute to mercury levels adversely affecting human 

health. 

Protection of Archaeological Resources.-This stipulation met the Department's statutory requirement for 

protection of archaeological resources. 

In addition to these stipulations, ITL clauses were 

provided in the final EIS to address MMS policy and 

practices and special concerns about the lease sale area. 

Lessees would be advised of the existing requirements 

pertaining to bird and mammal protection, specifically for 

the Arctic Peregrine Falcon, which is listed as threatened by 

the DOl and is protected under the Endangered Species Act 

of 1973, as amended (16 U.S.C. 1531 et seq.). The conduct 

of OCS mining activities would not conflict with the falcons 

if the activities were located away from known nest sites. 

Other ITL clauses addressed coastal zone management, 

subsistence activities, affirmative action, navigation safety, 

unitization, Clean Air Act Amendments, bonding and 

leasing requirements, and provision for a postlease Norton 

Sound review team. 

74 Proceedings, 1991 EEZ Symposium on Mapping and Research 

REVISED ENVIRONMENTAL IMPACT 

STATEMENT 

In responding to concerns over the accuracy of 

existing water quality data in the Norton Sound, MMS 

contracted with Battelle Northwest in 1989 to acquire 

additional trace-metal data using state-of-the-art collection 

and analytical techniques. The sampling results indicated 

that the levels of mercury detected in the water do not 

exceed established EPA criteria. Assessments appear to 

indicate that dredging does not contribute significant 

amounts of mercury to the water column. 

A decision was also made to work with the Public 

Health Service to obtain hair samples of women of childbearing age for trace-metal analysis because of concerns 

expressed that women who are heavy consumers of seafood 

(for example, red king crab) may have been exposed to high 

levels of methylmercury (organic form of mercury). The 

1989 sampling study, also conducted by Battelle Northwest, concluded that the methylmercury content in the hair 

samples was below harmful levels for indigenous coastal 

North American communities. A followup hair-sampling 

study undertaken during the fall of 1990 indicated that there 

are no consistent seasonal patterns or significantly high 

levels of methylmercury in the samples taken. Some samples showed a seasonal trend, and a few showed levels of 

methlymercury that exceeded the lower World Health 

Organization levels of concern (10-20 parts per million). 

However, the final report suggests that these higher levels 

result primarily from adsorption of methylmercury on to the 

hair from environmental sources, such as air, water, and 

soil and not as a result of diet. 

As a result of the information acquired in November 

1989, MMS held a baseline and monitoring workshop to aid 

in the design of studies to monitor water quality, assess 

habitat alteration, and examine the mercury effects on 

human health. Experts in the areas of water and sediment 

sampling, effects of trace metals in marine organisms, 

habitat alteration, and mercury effects on human health 

provided advice to MMS and CT. The workshop aided 

MMS in the design of environmental monitoring programs 

that allowed MMS to detail any changes that could result 

from a mining operation. 

MMS also responded to the potentially unavoidable 

effects on habitat alteration that dredging can pose. For 

instance, if mineral extraction activities occur, certain 

immotile organisms in the mine site may be destroyed. In 

December 1989, MMS deleted six blocks from the proposal 

to protect the red king crab habitat, reducing the sale area to 

34 whole and partial blocks containing approximately 

147,050 acres. This decision removed an area that MMS 

inferred to be critical habitat for red king crabs, therefore 

reducing the potential effect of dredging on the population. 

This deletion, in conjunction with the observed distribution 

of trench habitat outside the sale area, resulted in a total of 
about 68 percent of the trench habitat occurring outside the 

proposed sale area. Therefore, approximately 32 percent of 

the habitat deeper than the 30-m isobath occurred within the 

lease-sale area. The effects of mining on this area are 

monitored in accordance with Stipulation No. 1, Environmental Survey and Monitoring Program and Operations 

Management. The monitoring program allows for the identification of any unique or more limited habitats and 

communities and allows for mitigation of dredging activities within them. These actions minimize the effects of 

potential habitat alteration on marine plants and invertebrates. 

After the results of these studies were analyzed, a 

second draft EIS and Proposed Notice of Sale were issued 

on June 15, 1990 (U.S. Department of the Interior, 1990). 

This second draft EIS included an analysis of the effects of 

mercury on humans, based on the information obtained 

from the water sampling study and the results of the 

MMS-sponsored workshop. A second public hearing was 

held in Nome, Alaska, on July 19, 1990. Most concerns 

relative to mercury seemed to have been alleviated. 

In September 1990, WestGold officials announced 

permanent closure of operations in Nome, including shutdown of the offshore mining dredge Bima due to low gold 

prices and persistent operational losses. Therefore, MMS 

contacted industry representatives interested in the sale to 

determine if sufficient interest remained to continue the 

lease process. Results of this survey indicated continued 

industry interest. 

The final EIS was issued on March 8, 1991 (U.S. 

Department of the Interior, 1991), and incorporated comments from the public hearing and other sources. MMS 

prepared a consistency determination on March 8, 1991, 

and sent it to the State for review. On April 24, 1991, the 

State agreed with the determination that the lease sale was 

consistent with the Alaska Coastal Management Program to 

the maximum extent practicable. 

THE FINAL NOTICE OF SALE 

After a second industry survey in May 1991 indicated 

continued interest in the lease sale, the final Notice of Sale 

was published in the Federal Register on June 21, 1991. 

The notice focused on acreage identified as having the 

highest potential for placer gold and covered 34 whole and 

partial blocks encompassing about 147,050 acres (fig. 1). 

The area is located between 3 mi and 14 mi offshore Nome, 

Alaska, in Norton Sound. Water depths in the area range 

from 66ft to 99ft. The notice also outlined the terms and 

conditions of the sale and contained restrictions on operations in the form of stipulations and ITL clauses, which 

provided environmental protection and responded to concerns expressed during the prelease process. Leases resulting from this lease sale would have had an initial term of 20 

yr. The annual rental requirement was about $1.00 per acre, 

and the production royalty rate was 5 percent of the value of 

any and all gold concentrates and other minerals produced 

for recovered minerals. 

THE LEASE SALE 

On July 12 and on July 23, 1991, two separate but 

related legal actions were filed in district court requesting a 

preliminary injunction to stop the OCS Mining Program, 

Norton Sound Lease Sale (Nome Eskimo Community and 

others v. Lujan). The complaint was directed at all mineral 

activities in the Norton Basin and Bering Sea based on 

alleged aboriginal title to the villages' traditional hunting 

and fishing grounds on the OCS. Oral arguments were 

presented; however, the bid submission deadline for the sale 

closed at noon on July 23, 1991, and no bids were 

submitted. The Federal Government filed a note to the court 

stating that because no bids were received, a sale would not 

be held. The district court then issued an order denying the 

motion for a preliminary injunction. 

Subsequently, several companies were contacted and 

requested to provide some insight as to why no bids were 

submitted. Various reasons were given, including low gold 

prices, limited availability of mining vessels, lowest point 

of price curve swing, difficulty in obtaining capital financing, better opportunities in State waters, and legal uncertainty. The bidders' lack of response was apparently a 

combination of all of the above reasons. 

A Case Study of the Norton Sound Alaska Marine Mineral Lease Sale Process 75 
••~ U.S. Department olthe Interior 

I~ Minerals Management Service 

640 

15' 

ALASKA 

NQ3-7 

NORTON SOUND 

SOurce: usos. MMS 1:250.000 llasernaps 

Figure 1. Thirty-four blocks of Norton Sound lease sale. 

REFERENCES CITED 

Nelson, C.H., and Hopkins, D.M., 1972, Sedimentary processes 

and distribution of particulate gold in the northern Bering 

Sea: U.S. Geological Survey Professional Paper 689, 27 p. 

U.S. Department of the Interior, Minerals Management Service, 

and Bureau of Mines, 1987. An economic reconnaissance of 

76 Proceedings, 1991 EEZ Symposium on Mapping and Research 

640 I seal Norton Sound 15' Lease Sale Area 

NQ3-8 NQ3-7 Official Protraction 

Diagram Number 

- Area of Request 

5 0 5 10 15 20 

S'DmJTE MILES 

selected heavy mineral placer deposits in the U.S. Exclusive 

Economic Zone: Open File Report 4-1987. 

U.S. Department of the Interior, Minerals Management Service, 

Alaska OCS Region, 1988, OCS Mining Program Norton 

Sound Lease Sale, Draft Environmental Impact Statement. 

---1990, OCS Mining Program Norton Sound Lease Sale, 

Second Draft Environmental Impact Statement. 

---1991, OCS Mining Program Norton Sound Lease Sale, 

Final Environmental Impact Statement. 
Geological and Biological Investigations of Oregon's 

Nearshore Placer Deposits 

Richard M. Starr 

Oregon Department of Fish and Wildlife 

Dennis L. Olmstead 

Oregon Department of Geology and Mineral Industries 

INTRODUCTION 

In September 1989, the Secretary of the Interior and 

the Governor of Oregon announced the formation of a joint 

State-Federal Oregon Placer Minerals Technical Task 

Force. The purpose of the task force was to define the extent 

of black sand deposits offshore Oregon, evaluate their 

economic and strategic importance, and examine the environmental aspects of their development. The task force, 

with members and advisors representing government, academia, and industry, met four times during the period 

October 1988 to January 1990 and subsequently released a 

preliminary feasibility study (Oregon Department of Geology and Mineral Industries, 1990). The group met again in 

March and July of 1990 to commission a reconnaissancelevel field study, which was conducted during SeptemberOctober 1990. A cruise report detailing the accomplishments of the field study was released in April 1991 by the 

U.S. Geological Survey (Clifton and others, 1991). Analysis of field and laboratory data generated by the 1990 Placer 

Minerals Cruise was published by the Oregon Department 

of Geology and Mineral Industries ( 1991). 

The Oregon Placer Minerals Technical Task Force 

was supported by the Department of the Interior, Minerals 

Management Service, through cooperative agreement with 

the State of Oregon, Department of Geology and Mineral 

Industries. Cash and in-kind contributions for the 1990 

Placer Minerals Cruise were provided by the Minerals 

Management Service; the U.S. Bureau of Mines; the 

Marine Minerals Technology Center, University of Mississippi; the Oregon Departments of Environmental Quality, 

Geology and Mineral Industries, Fish and Wildlife, and 

Land Conservation and Development; the Oregon Division 

of State Lands; the Oregon Sea Grant College Program; and 

Portland State University. 

BACKGROUND 

The 1990 Placer Mineral Research Cruise represented 

reconnaissance-level efforts related to both the resource and 

the environment; the objectives of the September 1990 

cruise were to: 

• Identify the concentration, quality, and distribution of 

placer minerals with depth and 

• Collect information on living resources to help design 

environmental impact studies should the potential for 

mineral extraction be high. 

As a general strategy, the cruise focused on two 

areas, one off Cape Blanco and the other off Gold Beach 

(fig. 1), that had been identified in previous studies as 

having potential for placer mineral concentrations. The goal 

was to collect a minimum of four to six cores or bulk 

samples through the upper 6 m of shelf sediment in each 

target area. The location of these sample sites was to be 

established on the basis of magnetic and high-resolution 

acoustical profiling data collected in the initial phases of the 

cruise. Mineralogical samples collected from the target sites 

received preliminary examination onboard the vessel to 

assist with the field interpretation of the nature of the 

deposit and the selection of additional sampling sites. The 

bulk of the samples were taken to shore-based laboratories 

for detailed analysis following the cruise. 

NAVIGATION 

The navigational system used on the MN Aloha 

cruise was an 80386 DOS-based system using inputs from a 

DECCA 540 Del Norte transponder ranging system and an 

Ashtech Model XII GPS receiver. Del Norte was used for 

the majority of the cruise because of its greater positioning 

accuracy. The Global Positioning System (GPS) was used 

only when the ship was out of range of the land-based 

transponder stations or in areas of poor station geometry 

Geological and Biological Investigations of Oregon's Nearshore Placer Deposits 77 
125' 124' 43',..--------------,---.,...------___,43' 

c: 

ca 

CD 

(.) 

0 

(.) 

.... 

.... 

SURVEY 

AREA 

B Location map 

Figure 1. Areas of offshore research activity. 

(along baseline between stations). The positioning accuracy 

of the Del Norte system is about 5 m when three or more 

stations are used for the ranging calculations. GPS accuracy 

for this cruise was calculated by comparing 40,696 pairs of 

good Del Norte fixes with GPS fixes. The mean difference 

was about 21 m, with a standard deviation of 17 m. Loran-C 

was also used selectively. 

Seven different Del Norte shore transponder locations 

were used during the cruise. Three of them were located 

directly on bench marks; two were within 33 m of a 

benchmark and were located by tape measurement and 

theodolite and then crosschecked by azimuth to a distant 

benchmark or feature; another was located by resection with 

five other features; and the last, a temporary station used 

only briefly, was measured from a topographic quadrangle 

map. 

The DOS computer system gave a realtime numerical 

and graphical display that was used by the helmsman for 

line following and station reoccupation. Most station keeping was done by maneuvering the vessel about a temporary, 

bottom-anchored buoy. Del Norte positions were calculated 

by the computer program from the known locations of the 

shore transponders and the ranges. GPS positions were 

calculated by the Ashtech receiver and used by the computer program without modification. 

78 Proceedings, 1991 EEZ Symposium on Mapping and Research 

DATA COLLECTION AND SAMPLING 

Geophysics 

Geophysical data were gathered via magnetometry, 

high-resolution seismic profiling, and sidescan sonar systems. Six magnetic surveys were conducted in the Cape 

Blanco area, and two were run in the Gold Beach area, 

resulting in a total of 384 km of trackline (fig. 2). Seismic 

tracklines totaling 198 km were conducted in the study 

areas; in addition, two longer transects were conducted 

outside the study areas using loran-e navigation (fig. 3). 

These transects were from Cape Arago (69.9 km). Sidescan sonar tracklines totaling 188 km were conducted in the 

Cape Blanco West and Cape Blanco South areas. 

Geology 

Sediment samples for geological analyses were collected both by benthic grab and vibracore-vibralift. Surficial 

sediment samples were subsampled from all 68 0.1 m2 

Smith-Mcintyre grab samples with 10-cm2 by 1.5-cm-thick 

petri dishes. Grab sample locations are shown in figures 4 

and 5. Due to technical problems, only limited sampling 

was accomplished with the vibracore-vibralift. 

Biology 

Benthic infauna were sampled with the 0.1-m2 SmithMcintyre grab. Fish and benthic epifauna were sampled 

with a 3-m beam trawl and a 7 .3-m otter trawl. Sixteen tows 

totaling 24 km were conducted. In addition, adult Dungeness crabs were sampled with crab pots. Seabird and marine 

mammal observations were made over 351 km of trackline. 

Locations of biology sampling stations are shown in figures 

4 and 5. 

ENVIRONMENTAL AND BIOLOGICAL 

INVESTIGATIONS 

Biological surveys of nearshore sand areas off southem Oregon were designed to provide three primary types of 

information. Biologists attempted to (1) estimate species 

composition, diversity, and relative abundance of animals 

in the study area; (2) compare species diversity and relative 

abundance of fish and invertebrates living in areas containing deposits of heavy minerals with similar areas containing 

no deposits of heavy minerals; and (3) collect and analyze 

samples in a manner that will help determine appropriate 

statistical sampling designs should further studies be conducted. 

The biological sampling program demonstrated the 

existence of a complex array of productive and diverse 

habitats within the study area. Sand and gravel substrates 

sampled exhibited similar species composition, diversity, 
... 

~ 

0 

~ 

C\1 

.... I 

MERCATOR PROJECTION 

STANDARD PARALLEL= 42.6167° 

~ 

t'~~ 1: ~ 

1...:1 

42° 18' 

0 

0 

oMagnetic 

base 

station 

\ 

20 km 

10 nm 

Figure 2. Magnetometer lines, southern Oregon. 

0 

C\1 

0 

~ 

C\1 

.... I 

i:o 

'I:T 

~ C\1 

.... I 

. MERCATOR PROJECTION 

STANDARD PARALLEL= 42.1800° 

o._.c==~~===---25km 

o._ ____ c=====~-----15nm 

Figure 3. Seismic lines, Gold Beach to Coos Bay. 

N 

0 -

~ 

N 

-. 

Geological and Biological Investigations of Oregon's Nearshore Placer Deposits 79 
Trawls 7, 8, 12, 

13, 14, 15 

Trawls 9, 10, 

11, 16, 17 

Cape Blanco 

Port Orford 

• Benthic Infauna Sampling Station 

I Crab Pot String I Fish Trawl 

Ill Kelp 

Figure 4. Benthic infauna stations, crab pot locations, and fish trawls; northern portion of the study area. 

80 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Trawls 1, 2, 

3, 4, 5 

r...J 

35 1D 

) \· 

Cape Sebastian 

• Benthic Infauna Sampling Station 

I Crab Pot String 

r Fish Trawl 

Ill Kelp 

Figure 5. Benthic infauna stations, crab pot locations, and fish trawls; southern portion of the study area. 

Geological and Biological Investigations of Oregon's Nearshore Placer Deposits 81 
and relative abundance to other Oregon nearshore areas. 

Benthic grab samples showed that the sand substrates were 

characterized by an infaunal assemblage of worms, mollusks, and crustaceans. Trawls caught species of commercial interest including Dungeness crab, English sole, butter 

sole, sandsole and Pacific tom cod, as well as many forage 

species. The complex of different habitats within a small 

geographic area may be unique on the Oregon coast. Bird 

observations made during the cruise showed the highest 

densities inside Orford Reef. 

The substrate types encountered in the study area 

included sand, gravel, rock, and rock with kelp. Each type 

of substrate harbors different types of fish and invertebrates 

and requires different sampling techniques. Logistical constraints allowed us to sample only sand and gravel substrates. Rock, kelp, and water column habitats should also 

be sampled in the future to adequately characterize the biota 

of study area. Sidescan sonar should be used to map the 

distribution of sand, gravel, and rock habitats. 

Additional work is needed to more clearly describe 

the character and importance of the gravel and kelp habitats 

in the study area and their relation with sand habitats. The 

catch of adult cabezon with stomachs full of flatfish and 

crabs over sand substrates indicates that some fish may take 

refuge in rocky areas and forage on the sand substrates. 

Food habit studies would be appropriate to evaluate interactions between species in the complex array of habitats 

present in the study area. The water column habitat should 

also be studied, as particulate matter from a mining operation would impact animals in the water column. 

Since large concentrations of heavy minerals were not 

positively identified, we could not compare target and 

control stations. The species observed, along with evidence 

of dynamic physical environment, suggest that it may be 

difficult to identify differences in biota between areas 

containing heavy minerals and nearby sand areas without 

minerals. Future work should be designed to examine 

relations between species distribution and metal concentrations. We also recommended studies of suspended metal 

uptake by organisms. If a target location is selected in future 

work, a more direct comparison between targets and controls should be made. If mining occurs, an area within the 

concentration of heavy minerals should be set aside as a 

control site to compare biological changes within a control 

to biological changes in the mined area. 

Data are presented in the report to help design future 

studies that are statistically valid. Based on our results and 

those of past studies, we recommended that future benthic 

infauna sampling be stratified by both depth and geographic 

separation. Suggested depth strata are 0-15 m, 15-35 m, 

and 35-50 m. The Blanco area should be a separate stratum 

from the Rogue Reef/Cape Sebastian area. An additional 

stratum should be located off the mouth of the Rogue River 

to adequately describe this river mouth area. Station locations should be chosen at random within the strata. Control 

82 Proceedings, 1991 EEZ Symposium on Mapping and Research 

stations should be in a similar stratum as the target stations 

but distant enough to ensure they are not disturbed. 

We recommended that a 0.5-mm sieve be used in the 

study area for impact analysis. Future projects should also 

weigh the biota so that biomass can be estimated. To 

describe the recovery of an impacted area, it would also be 

desirable to obtain life-history information pertaining to 

recruitment, growth, and reproduction for the most abundant species. 

Crab pots should be used if the purpose of a sampling 

project is to estimate the carapace width of commercialsized crabs in an area. Conversely, trawls should be used if 

the purpose is to estimate the numbers of all size classes of 

crabs in the study area. Trawling for crabs should occur at 

night to adequately sample young of the year. 

Fish data collected from trawls indicate that an 

intensive trawl sampling program may be needed to accurately characterize changes in fish density or standing crop 

that would be attributable to an environmental disturbance 

such as mining. Future researchers may need to accept a 

large probable error or conclude that both number per 

hectare and weight per hectare are poor indicators of 

environmental disturbance in the study area. Ctenophores, 

crangonid shrimp, mysid shrimp, and amphipods were 

caught in large numbers. This study concentrated on juvenile fish. Future work to evaluate environmental impacts 

should also include studies of adult fish. 

The results of the bird surveys indicate that nine 

transects averaging over 4 km in length are sufficient to 

describe more than 90 percent of the species observed in 

each region. Any future attempts to document changes in 

bird populations in the study area should account for 

variations in the number of birds observed due to wind 

conditions. 

A survey of mammal rookeries also is needed to 

estimate the number of pinnipeds in the study region. 

GEOPHYSICAL INVESTIGATIONS 

Geophysical surveys were conducted west and south 

of Gold Beach (mouth of the Rogue River) and west and 

south of Cape Blanco. Magnetic anomalies in the Gold 

Beach area appeared related to bedrock structures rather 

than concentrations of placer minerals. None of the magnetic anomalies in the two target areas exhibited the 

shore-parallel shape and orientation of the anticipated 

drowned beach strand placer deposits. High-resolution seismic surveys were also conducted in the four areas, delineating unconsolidated sediment thicknesses of between 0 

and 50 m, but showing little internal structure within the 

sand section with which to aid interpretation. Limited 

sidescan sonar coverage demonstrated the presence of 

extensive surficial gravel patches in the vicinity south of 

Cape Blanco, indicating that modem sediment in this area is 

probably a thin veneer over older sediments. 
GEOLOGICAL SAMPLING AND RESULTS 

Geological sampling to depth in the sand section with 

the vibralift-vibracore drill was frustrated by the prevailing 

oceanographic conditions and equipment breakdowns. Four 

vibralift stations were sampled to a depth of 6 m south of 

Gold Beach, and one shallow sample ( < 1 m) was recovered 

west of Cape Blanco. No vibracores were obtained. However, additional geological sediment subsamples were 

obtained from each of the 68 surficial grab samples taken 

for the biology program. 

Nine different target sites were identified in the 

Rogue River area on the basis of anomalous concentrations 

of heavy minerals in the surficial sediment and (or) magnetic anomalies. Of these nine, five sites were thought to 

represent possible paleoshoreline deposits. Two other sites 

were thought to result possibly from concentration on the 

south side of a paleoheadland, and the remaining two sites 

were thought to owe any economic potential to their 

proximity to the Rogue River mouth. 

In every case, the sand beneath the sea floor texturally and mineralogically resembles sand at the present 

surface (table 1). All this sediment was very likely deposited under conditions similar to those of the present time on 

the modem-day Oregon shelf. Magnetic anomalies in the 

Rogue River shelf area, which were previously attributed to 

concentrations of heavy minerals in the surficial sediments, 

are assigned on the basis of the current study to near-surface 

masses of bedrock. There is no geological or geophysical 

evidence for fossil-beach deposits in the Holocene section 

on this part of the shelf. The likely contact with underlying 

Pleistocene sediment was encountered 6 m below the sea 

floor in Vibralift 03 A, and it lies at least 5-6 m below the 

sea floor at the locations of the other vibralift samples. The 

character and heavy mineral content of the Pleistocene 

sediment remains unknown. 

Potential heavy mineral concentrations lie at the floor 

of the paleochannels of the Rogue River that were identified 

on the shelf west of the present river mouth. The amount of 

overburden (25-50 m) that covers any such deposits makes 

any recovery difficult and costly. 

Target sites in the Cape Blanco area were identified 

on the basis of prior studies and were thought to include 

paleoshoreline deposits, paleo headland deposits, and 

deposits that formed at river mouths when sea level stood at 

a lower position. Inability to collect samples at depth in the 

Cape Blanco area limits the geological interpretation of the 

nature and mineralogy of substrate on this part of the shelf. 

Magnetometer data and available sample information suggest that surficial concentrations of heavy minerals 

observed off Cape Blanco do not overlie fossil buried 

beaches. Such beaches, if enriched in heavy minerals such 

as magnetite, would be expected to produce linear magnetic 

anomalies trending more or less parallel to the present 

shoreline. The magnetic survey shows no linear trends in 

this area, and most of the anomalies appear to be the small, 

sharply delineated type that reflects the magnetic susceptibility of the near-surface bedrock below the sea floor. 

Small box cores taken from the Smith-Mcintyre grab 

samples contain concentrations of heavy minerals in the 

upper 7 em that are somewhat mixed by subsequent faunal 

burrowing and winnowing by fairly recent storms. The 

samples that show these concentrations are distributed over 

a broad area west of Cape Blanco in water depths that range 

from 17 to 48 m. Data suggest that modem-day storms 

concentrate heavy minerals over a broad area west of Cape 

Blanco. It is likely that concentrations of heavy minerals 

previously detected in the surface sediment in this area 

result from storm winnowing of modem shelf sediment 

rather than from reworking of underlying fossil beach 

material. 

If heavy mineral concentrations on this part of the 

shelf are produced by present-day storms, it is questionable 

whether the concentration will increase with depth. The 

most realistic geological model for these deposits, based on 

our limited data, is of a probable areally extensive concentration of heavy minerals at a grade similar to that at the sea 

floor. The thickness of the concentration is unknown. 

Elsewhere on the southern Oregon shelf, the thickness of 

the modem shelf sand depends on the neotectonic setting. In 

areas of downwarp, such as near Cape Sebastian, the 

Holocene sediment may be more than 6 m thick. Cape 

Blanco, however, lies along a line of apparent uplift, near 

the axis of an anticline in the onshore Pleistocene deposits. 

The Holocene sediment in this setting may be little more 

than a veneer over underlying Pleistocene material (as it 

seems to be in the Cape Blanco south area). Accordingly, 

the heavy-mineral-rich sand may be very thin in this area. 

On the other hand, much of this part of the shelf is covered 

by more than 10 m of unconsolidated sediment above the 

bedrock surface; it is possible that a significant amount of 

this material formed on Pleistocene shelves under conditions similar to those of the present day. If so, the 

placer-bearing section could be 6-9 m or more thick. 

Detailed magnetic modeling or a successful deep coring 

program would seem the only ways to resolve the question. 

In summary, the surficial samples collected exhibited 

some enrichment of heavy minerals in the Cape Blanco area 

but not the Gold Beach area. Samples taken to depth 

offshore Gold Beach did not increase in heavy mineral 

concentration with depth in the sand section; the subsurface 

sand was texturally and mineralogically similar to samples 

at the surface. 

Extensive mineralogical and elemental analyses were 

conducted on depth fractions of all the vibrant samples. 

Only trace amounts of gold, zirconium, and platinum group 

metals were found. Titanium and chromium minerals were 

found in all samples, but only the titanium-bearing ilmenite 

in the Cape Blanco sample was in sufficient concentration 

( ~3 percent Ti) to rival existing onland sources. 

Geological and Biological Investigations of Oregon's Nearshore Placer Deposits 83 
Table 1. Chemical analysis of Oregon placer samples 

[Assays forTi and Zr by inductively coupled plasma-atomic emission spectroscopy; assays for Cr and Fe by atomic absorbtion spectrophotometry; pet, 

percent] 

Station 1: Cape Blanco 

ID Depth, Analysis, pet Calculated analysis, pet 

number ft Ti Cr Zr Fe Ti02 Cr2 0 3 Zr02 Fe20 3 

ME-2321 2 3.32 0.83 0.038 8.09 5.54 1.21 0.05 11.57 

Station 2: Gold Beach 

ID Depth, Analysis, pet Calculated analysis, pet 

number ft Ti Cr Zr Fe Ti02 Cr2 0 3 Zr02 Fe2 0 3 

ME-2331 3 0.49 0.15 0.011 5.6 0.82 0.22 0.01 8.01 

ME-2332 6 .42 .12 <.008 4.58 .71 .18 <.01 6.55 

ME-2333 9 .47 .15 <.008 4.99 .78 .22 <.01 7.14 

ME-2334 12 .41 .15 <.008 4.67 .69 .22 <.01 6.68 

ME-2335 15 .34 .08 <.008 4.06 .57 .12 <.01 5.81 

ME-2336 16 .33 .08 <.011 3.87 .56 .12 .01 5.53 

Station 3 Rogue River 

ID Depth, Analysis, pet Calculated analysis, pet 

number ft Ti Cr Zr Fe Ti02 Cr20 3 Zr02 Fe20 3 

ME-2338 5 0.42 0.14 0.008 4.09 0.69 0.20 0.01 5.85 

ME-2339 10 .46 .19 <.008 5.16 .77 .28 <.01 7.38 

ME-2340 15 .50 .22 .008 5.39 .84 .32 .01 7.71 

ME-2341 20 .51 .19 .008 5.57 .85 .28 .01 7.97 

Station 4: Cape Sebastian 

ID Depth, Analysis, pet Calculated analysis, pet 

number ft Ti Cr Zr Fe Ti02 Cr20 3 Zr02 Fe20 3 

ME-2343 3 0.44 0.19 <0.008 4.63 0.73 0.28 <0.01 6.62 

ME-2344 6 .38 .12 .01 3.96 .63 .18 .01 5.66 

ME-2345 9 .50 .16 <.008 4.97 .83 .23 <.01 7.11 

ME-2346 12 .45 .12 <.008 4.49 .75 .18 <.01 6.42 

ME-2347 15 .38 .12 <.008 4.19 .64 .18 <.01 5.99 

ME-2348 17 .63 .17 <.008 6.16 1.06 .25 <.01 8.81 

ME-2349 20 .64 .17 .01 5.78 1.07 .25 .01 8.27 

Station 5: North Cape Sebastian 

ID Depth, Analysis, pet Calculated analysis, pet 

number ft Ti Cr Zr Fe Ti02 Cr2 0 3 Zr02 Fe20 3 

ME-2350 3 0.34 0.1 <0.008 3.83 0.57 0.15 <0.01 5.48 

ME-2351 6 .35 .11 .017 3.87 .59 .16 .02 5.53 

ME-2352 9 .48 .25 .009 4.8 .79 .37 .01 6.86 

ME-2353 12 .46 .11 .009 4.86 .77 .16 .01 6.95 

ME-2354 15 .60 .17 .008 5.79 1.01 .25 .01 8.28 

ME-2355 20 .55 .15 .011 5.61 .93 .22 .01 8.02 

84 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Beneficiation testing conducted on vibralift subsamples demonstrated that the Cape Blanco heavy mineral 

product could be improved by standard beneficiation techniques. The lack of core samples to depth offshore Cape 

Blanco leaves the heavy mineral potential there unknown. 

However, the geological resource reconnaissance results, as 

a whole, fail to show the presence of an appreciable heavy 

mineral resource in either target area. 

REFERENCES CITED 

Clifton, H.E., and others, 1991, Cruise report, 1990 Oregon 

placer mineral research cruise (A1 90WO), September 21-

October 3, 1990: U.S. Geological Survey Open-File Report 

91-279, 81 p. 

Joint State-Federal Oregon Placer Marine Minerals Technical Task 

Force, 1991, Preliminary resource and environmental 

data-Oregon marine place minerals: State of Oregon 

Department of Geology and Mineral Industries Open-File 

Report 0-91--02. 

Joint State-Federal Oregon Placer Minerals Task Force, 1990, 

Preliminary Feasibility Study: Oregon placer minerals: State 

of Oregon Department of Geology and Mineral Industries 

Open-File Report 0-89-12. 

Geological and liological Investigations of Orqon's Nearshore Placer Deposits 85 
Offshore Geology of the Gulf of the Farallones Region 

Project-A Model for Environmental Research 

on Continental Margins off Major Urban Areas and 

in National Marine Sanctuaries 

Herman A. Karl 

U.S. Geological Survey 

Abstract 

The U.S. Geological Survey began a major geologic 

and oceanographic study offshore of the San Francisco 

Bay in 1989 in an area that included a large part of the Gulf 

of the Farallones National Marine Sanctuary. This investigation, the first of several now being conducted adjacent 

to major population centers, was designed to establish a 

scientific data base on a segment of continental shelf that 

can be used to evaluate and monitor the impact of human 

activities on the marine environment. In 1990, this project 

expanded in scope when the U.S. Geological Survey 

conducted a multidisciplinary investigation sponsored by 

the U.S. Geological Survey, the U.S. Environmental Protection Agency, the U.S. Army Corps of Engineers, the 

U.S. Navy, and the National Oceanic and Atmospheric 

Administration to survey and sample the continental slope 

west of the Farallon Islands. The Federal Agency cooperative study was designed to provide information on the 

location and distribution of 47,800 containers of low-level 

radioactive waste and data on areas being considered as 

sites for the disposal of dredge material. 

INTRODUCTION 

The marine environment is now facing important 

issues of universal concern such as pollution, resource 

availability and management, hazards, and global and 

climatic change. The oceans will be used increasingly as a 

source of food and mineral and petroleum resources, as a 

place for recreation, and as a repository for waste products. 

To assure that these human demands are met responsibly, 

the public and the public's representatives must have the 

best scientific data available to guide them in making 

choices about uses of the marine environment. 

The U.S. Geological Survey (USGS) is conducting 

systematic environmentally focused geologic investigations 

called geologic inventory projects on the continental shelf 

86 Proceedings, 1991 EEZ Symposium on Mapping and Research 

and slope within the U.S. Exclusive Economic Zone (EEZ). 

Areas that are offshore major population centers have been 

and will continue to be most affected by human activities, 

and, therefore, the initial study sites are adjacent to large 

urban complexes. Eighteen areas in the coastal ocean (8 

designated and 10 proposed) have been set aside as national 

marine sanctuaries. These pristine, unusual, rich, and 

diverse ecosystems, particularly those adjacent to major 

urban areas, are also impacted and threatened by societal 

use of the oceans. The first of the geologic inventory 

projects, the Offshore Geology of the Farallones Region, 

was begun offshore the San Francisco Bay in 1989 where a 

national marine sanctuary is situated adjacent to a dense 

population center (fig. 1). 

PHILOSOPHY AND STRUCTURE OF THE 

FARALLON REGION PROJECT 

Each geologic inventory project is designed and 

conducted as a multidisciplinary research study. The basic 

research must be relevant to one or more specific social 

issues and must also provide baseline information that can 

be used to design other environmental studies. Most importantly, the data derived from the project must be communicated in a timely way that is clearly understandable not 

only to professional scientists but also to the public and 

those charged with management decisions concerning multiple use of the offshore areas. 

The continental margin offshore the San Francisco 

Bay area was chosen as the site of the first geologic 

inventory project for six reasons: 

(1) The Gulf of the Farallones National Marine Sanctuarya unique marine ecosystem -encompasses a large part 

of the Gulf of the Farallones. The geology and oceanography of this area are poorly understood. 
IS' 

Figure 1. Continental shelf and slope study areas in the 

Gulf of the Farallones. Inset shows sonograph mosaic of 

intricate linear scour depressions on the continental shelf. 

Sidescan sonar coverage was obtained over the entire 

(2) The Gulf of the Farallones and adjacent waters are an 

important commercial and recreational fisheries area; 

fish products from the Gulf of the Farallones are 

exported worldwide. 

(3) Selected areas of the ocean floor have been used and are 

being considered as disposal sites for material dredged 

from San Francisco Bay. There is a great need to gather 

information about the geologic and oceanographic processes on the continental margin to understand the 

effects of these disposal sites on the environment. 

Kilometers 

Gulr of the Farallones National 

Marine Sanctuary boundary 

Preliminary study area 

USGS Farallon shelf segmenl sludy 

Area that may contain radioactive waste 

Radioactive waste dumpsite 

Area covered by sidescan sonar mosaic 

10 

Nautical miles 

pre liminary study area. The shaded part around the middepth (900 m) radioactive waste dumpsite is the sanagraphic mosaic shown in figure 9; the entire 1-km swath 

mosaic of th is area is shown in figure 8. 

(4) More than 47,800 55-gal drums and other containers of 

low-level radioactive waste were dumped on the continental margin between 1946 and 1970. These drums 

now litter a large area (1 ,200 km2

) of the sea floor 

within the marine sanctuary . The exact location of the 

drums and the potential hazard the drums pose to the 

environment are unknown . 

(5) Many faults have been mapped in the Gulf of the 

Farallones; for example, the San Andreas fault crosses 

the gulf near the Golden Gate. These faults are a 

Offshore Geology of the Gulf of the Farallones Region Project 87 
potential seismic risk for the cities of the San Francisco 

Bay area. 

(6) Study of the ocean environment complements ongoing 

USGS investigations of San Francisco Bay and provides an opportunity to study an estuarine-shelf-slope 

system. 

A wide variety of surveying and sampling techniques 

and technologies is required to sample and measure the 

many physical products and processes that characterize the 

continental shelf and slope environments. The Farallones 

Region project is multidisciplinary and consists of four 

basic elements: 

( 1) Framework geophysics and geology to investigate deep 

structure to assess seismic risk. 

(2) High-resolution geophysics to investigate near-surface 

structure and stratigraphy, sediment body geometries, 

and surface morphologies. These studies will help 

evaluate seismic and slope stability hazards and areas of 

excessive sediment erosion and deposition. 

(3) Characterization of the sea floor with sidescan sonar, 

bottom photography, high-resolution sub bottom profiling systems, acoustic profiling systems, and core samples. Sediment samples and cores are used for textural, 

geotechnical, mineralogical, geochemical, and paleontological studies. The primary objectives of these activities are to construct a sonographic mosaic of the sea 

floor and a high resolution bathymetric map as survey 

bases and to use the natural sediments as tracers for 

identifying pathways of sediment and pollutant transport. 

( 4) Quantitative investigation of sediment transport and 

ocean currents especially near the seabed to measure 

and predict rates of sediment and pollutant transport. 

The USGS began this multidisciplinary project in 

1989 by mapping and sampling the continental shelf east of 

the Farallon Islands (fig. 1). In 1990, the project expanded 

in scope when the USGS conducted an investigation sponsored by the U.S. Geological Survey, U.S. Environmental 

Protection Agency (EPA), U.S. Army Corps of Engineers 

(USACE), U.S. Navy (USN), and the National Oceanic and 

Atmospheric Administration (NOAA) to survey and sample 

the continental slope west of the Farallon Islands (fig. 1). 

This cooperative study by these Federal agencies was 

designed to provide information on the location and distribution of the drums of low-level radioactive waste and 

geologic data on areas being considered as sites for disposal 

of dredge material from San Francisco Bay (Karl and 

others, 1990). 

DATA COLLECTION TECHNIQUES AND 

RESULTS 

Many surveying and sample techniques were used 

during both the shelf and slope investigation~. Owing to the 

brevity of this article, only the results obtained using 

88 Proceedings, 1991 EEZ Symposium on Mapping and Research 

sidescan sonar surveying (shelf and slope study), sediment 

sampling (shelf study), and bottom photography (slope 

study) techniques are described and illustrated in the following sections. Sediment sampling and bottom photography are common and easily understood techniques. Sidescan sonar techniques are not as straightforward, and a brief 

explanation is provided in the following paragraph. 

Sidescan sonar is an especially valuable tool that 

allows scientists to characterize the morphology of the sea 

floor by swath mapping. Sidescan sonar provides an acoustic image or sonograph of the sea floor that is similar to a 

satellite image of the Earth's land surface. As the sidescan 

sonar instrument is towed behind a ship along previously 

determined tracklines, the sonar continuously emits pulses 

of sound that ensonify strips or swaths of sea floor. The 

width of the swaths depends upon the type of sidescan sonar 

system. Swaths ranged from 200 m to 5 km in the 

Farallones study. When constructing a mosaic, tracklines 

are spaced so that adjacent swaths overlap by 10 to 20 

percent. Sidescan data are processed by computers, and a 

digital mosaic of a chosen area of sea floor is progressively 

built by overlapping and joining adjacent swaths. Shades of 

gray that range from black to white define features of the 

sea floor and represent varying energy levels of sound 

returned from the sea floor, hence, the acoustic image. 

Differences in the energy of the backscattered sound are 

related to sediment grain size, surface roughness, hardness, 

and slope of the sea floor. These sea floor characteristics 

reflect the host of geologic processes that have produced the 

sea-floor environment. The sonographs are used to define 

the geologic and morphologic setting of the study area, to 

interpret geologic processes operating on the continental 

margin, and to provide information relevant to environmental issues. When information on large areas is required and 

limited survey time is available, a reconnaissance method is 

used instead of detailed swath mapping. Data are collected 

along widely spaced tracklines to obtain a general overview 

of the area. 

Navigation is a critical component of any offshore 

survey so that identical features on adjacent swaths overlap 

and other data sets can be registered to the sonographic 

mosaic. Four systems were used to navigate the ship during 

the Farallones study: (1) Global Positioning System (GPS); 

(2) LORAN-C, either hyperbolic or rho-rho; (3) shorebased, line-of-sight transponder net; and (4) long baseline 

bottom transponder net. The primary system used for 

realtime positioning was chosen either manually by the 

navigator or automatically by the computer. Steering of the 

ship was aided by a trackline-following program displayed 

on a monitor both at the helm and at the navigation station. 

Positional accuracy of navigation tracks varied between a 

few meters when in range of the shore-based transponders 

or long baseline system to as much a 100 m of the pre plotted 

tracks when using loran-C and GPS. The long baseline 
Figure 2. Location map showing reconnaissance tracklines on the shelf and analog mosaic area (shaded rectangle). 

system was used to navigate only during a small part of the 

5-km swath survey on the slope. 

CONTINENTAL SHELF SURVEY 

Three cruises were conducted in 1989 on the continental shelf between Cordell Bank and Half Moon Bay east 

of the Farallon Islands (fig. 1). Reconnaissance surveys 

were conducted in January by using high-resolution sidescan sonar systems (Chin and others, 1989). These systems 

are capable of resolving features as small as ripples that 

have wavelengths of tens of centimeters and heights of a 

few centimeters. Approximately 2,500 line km of sidescan 

imagery were collected during these surveys (fig. 2). 

Regional reconnaissance tracks were spaced nominally 

4 km apart in a rectilinear pattern with the systems set at a 

200-m swath. Although the high-resolution systems are 

capable of resolving very small objects, only small areas 

can be surveyed in a given period of time. In addition to the 

reconnaissance tracks, a small (300-km2

) area was surveyed 

at a trackline spacing of 100 m so that adjacent swaths 

could overlap, permitting the construction of a mosaic of the 

entire area (fig. 2). High-resolution seismic-reflection and 

Offshore Geology of the Gulf of the Farallones Region Project 89 
Sample Locations 

kilomolenl 

10 21l 

38° 

37"45' 

'@. •G74 

37°30' 

'\ •oes 'G11 'G84 

'003 

Gl2 

GIIO • •GU 

II 017 

122°15' 122°10' 

Figure 3. Station locations of sediment samples showing regional grid of 97 stations and high-density grid of 171 stations. 

bathymetric profiles were also collected along many of the 

reconnaissance tracks to provide data on sediment thickness, stratigraphy, and morphology. Ninety-seven samples 

of surficial sediment were collected at the intersections of 

the reconnaissance tracks spaced nominally 4 km apart (fig. 

3). A denser grid of 171 samples spaced nominally 1 km 

apart was collected within the small area at the 100 m 

sidescan trackline spacing (fig. 3). 

Data from the January surveys were used to select a 

site to mosaic with a wide swath (500-1 ,000 m) highresolution sidescan system in July 1989. The chosen area 

was an 800-km2 area on the central shelf east of the Farallon 

Islands between Pt. Reyes and the Golden Gate and a 200-

km2 area of the upper slope west of the Farallon Islands 

(fig. 4). The sidescan data were collected as analog data, and 

these data were then digitized using onboard computers. 

The sidescan data were computer processed in pseudorealtime, and an enhanced, geographically correct mosaic 

constructed onboard ship (Danforth and others, 1991). 

90 Proceedings, 1991 EEZ Symposium on Mapping and Research 

CONTINENTAL SLOPE SURVEYS 

An investigation of the continental slope of the 

Farallon Escarpment was conducted in July 1990 to provide 

scientific data vital to the programmatic interests of EPA, 

USACE, USN, NOAA, and USGS. The investigation was 

planned to fulfill four objectives: 

(1) EPA and USACE required data to begin the Environmental Impact Statement (EIS) process for the determination of deep-ocean sites for the disposal of material 

dredged from San Francisco Bay. 

(2) While the EIS process proceeded for the selection of 

permanent disposal sites, the USN proposed the use of 

an existing chemical munitions dumpsite as an interim 

disposal site for dredge spoils. The USN needed data 

from that dumpsite area to submit to EPA. 

(3) The Gulf of the Farallones National Marine Sanctuary 

(GFNMS) administered by NOAA requested that 

USGS survey areas within the marine sanctuary in order 
Figure 4. Trackline map of AMS-120 sidescan sonar survey. Tracks are spaced about 500 m apart. Digital sonographic 

mosaic of the rectangular area (800 km2

) on the continental shelf is reproduced in figure 1. 

to detect drums that contain low-level radioactive 

waste. 

(4) USGS had begun mapping the continental shelf as 

described in the previous section. The programmatic 

interests of the other Federal agencies provided USGS 

with an opportunity to expand the geologic inventory 

shelf surveys to the continental slope. 

Sidescan sonar data , high-resolution seismicreflection data, bathymetric data, optical images of the 

seabed, and gravity cores were collected during two cruises 

in summer 1990. Four sidescan mosaics of different resolution were constructed from data collected with a midrange 

deep-towed sidescan system (fig. 1). The sidescan data 

were computer processed in pseudo-realtime, and mosaics 

constructed onboard ship (Danforth and others, 1991). A 

regional 5-km swath survey of 3,300 krn2 from the shelf 

break at about 200-,m water depth to the basin floor at about 

3,200 m was done for the EPA and USACE. A survey (200 

krn2

) with the system set at the 2-km swath setting was done 

for the USN. Two surveys, one at the 1-km swath setting 

(120 km2

) on the slope and another at the 500-m swath 

setting (70 krn2

) on the shelf, were done for NOAA. The 

surveys completed for NOAA were designed to detect 

barrels of low-level radioactive waste and will be described 

in more detail in the following section. Camera transects 

verified the interpretation of these surveys. 

Offshore Geology of the Gulf of the Farallones Region Project 91 
SURFACE SEDIMENT TEXTURE 

Kilometers 

10 20 

37•so· 

37°20' ~~~~:;_j_~_L____\.,=-._~=-=---.....c.:::::L~_L __ _Jj____!_ ____ ....:::==-----L-'---

-123"30' -123°10' -122"50' -122"30' 

Figure 5. Sediment texture plot based on regional grid of 97 samples. 

SELECTED RESULTS 

Continental Shelf 

The distribution of surficial sediment textures based 

on the regional grid of 97 stations suggests that depositional 

processes in the Gulf of the Farallones are complex (Maher 

and others, 1991). A 20-km wide corridor of sand extends 

westerly from the Golden Gate to the Farallon Islands (fig. 

5). Silty sand and sandy silt bound the corridor to the 

northwest and southeast, and a tongue of silt from the north 

extends around Pt. Reyes (fig. 5). More detailed analysis of 

the sediment texture reveals a slightly more complex 

regional distribution as shown, for example, by a plot of 

mean grain size (fig. 6). The increased complexity is well 

illustrated by examining the cross-shelf corridor of sand 

defined in figure 5. Plotting the mean grain size at 1-phi 

intervals shows that patches of medium and coarse sand 

exist within a field of fine sand and that sediment texture 

92 Proceedings, 1991 EEZ Symposium on Mapping and Research 

becomes coarser closer to the Farallon Islands (fig. 6). 

Increased sampling density reveals an even more intricate 

pattern of sediment texture. Note the area of dense stations 

(171 stations spaced 1 km apart) on figure 3. Sediment in 

this area, based solely on analysis of samples from the 

regional grid of 97 stations, is uniformly fine sand (fig. 6). 

Data from the grid of 171 stations (also plotted at a 1-phi 

interval) demonstrate that the area actually consists of a 

pattern of mean grain sizes that range from fine to very 

coarse sand (fig. 7). This level of sampling density provides 

data important to interpretation of the depositional processes operating in the Gulf of the Farallones. However, it is 

impractical to sample the entire shelf at this level of density. 

Moreover, even with such a dense sampling grid, it is still 

necessary to interpolate boundaries between textural fields. 

Sidescan sonar, on the other hand, provides continuous 

information about elements of the sea floor. The most 

intricate textural patterns are clearly revealed when adjacent 

sidescan swaths are joined into a mosaic of a large area of 
MEAN GRAIN SIZE 

Kilometers 

10 20 

37°50' 

37°40' D-1 phi Coarse sand . 

. 1-2phi Medium sand 

D2-3phi Anesand 

37"30' ~;~34phi 

~4-5phi Coarse siH 

-123°10' -122"50' -122"30' -122°10' 

Figure 6. Areal distribution of mean grain size based on regional grid of 97 samples. phi; a measure of grain size. 

the sea floor and the images verified with samples of 

sediment collected at selected sites. 

The reconnaissance sidescan sonar survey of the shelf 

revealed at least three fields of bedforms (ripples, dunes, 

and scour lineations generated by ocean currents) between 

Pt. Reyes and Half Moon Bay. Owing to the widely spaced 

and nonoverlapping sonographs, it was impossible to establish the absolute boundaries and geometric relations of the 

bedform fields. Of particular interest were a series of broad 

(as wide as 2 km), shallow (1-3 m deep) depressions 

floored by coarse sand and large wave-generated ripples. In 

order to define the pattern and limits of the field of 

depressions, an 800-km2 (about 235-nmi2

) area was surveyed with overlapping swaths, and a computer-processed 

mosaic was constructed on board ship (fig. 1). This study is 

the first to map and define the field boundaries and thereby 

establish the geometry and spatial relations to other shelf 

features of depressions such as these. The origin of these 

depressions is controversial. The intricate pattern of depressions and ripples manifests a dynamic and complex sediment transport system that varies with time and space. 

Information from the mosaic has several practical applications. For example, the evidence of strong currents, as 

indicated by large ripples in coarse grained sand, suggests 

that dredge material and pollutants disposed of at sites on 

the shelf could be redistributed over large areas. Also, 

commercial fisherman can use the mosaic to locate substrate 

preferred by bottom fishes and crabs. 

Continental Slope 

The 500-m and 1-km swath mosaics were used to 

detect and map the distribution of barrels and other containers of low-level radioactive waste. Because only 150 barrels 

were reported to be dumped at the shelf site, we focus on 

the interpretation of the 1-km mosaic in an area where 3,500 

barrels were reported to have been dumped on the slope. 

Small objects are difficult to detect on the rugged continenOffshore Geology of the Gulf of the Farallones Region Project 93 
37"53' 

MEAN GRAIN SIZE 

0 2 

~ -1-0 phi .. 

Gill 0-1 phi 

37"51' 

[I 1-2 phi 

~ - 2-3 phi 

37"49' II 3-4 phi 

Figure 7. Areal distribution of mean grain size based on detailed grid of 171 samples. phi; a measure of grain size. 

tal slope . Ambient levels of backscattered acoustic energy 

are relatively high, and sound paths are complex owing to 

the intricate morphology and steep slopes. Unless a strong 

signal is received from an object, it may not make a visible 

record on the sonar image. Even under these nonoptimum 

conditions, numerous small targets were detected on the 

sonographs (fig . 8). Many of these are interpreted as 55-gal 

drums. This interpretation, however, has been verified at 

only one location (fig . 9). This location, a small canyon just 

to the south of the 900-m dumpsite , was chosen for three 

reasons: (1) numerous small objects occur over the area, (2) 

some of the objects are arranged in a linear pattern, and (3) 

the sea floor relief is sufficiently subdued so that risk to the 

underwater camera system is minimal. Five 55-gal drums 

were observed with the underwater video-camera system 

(fig. 9). The drums are in various states of deterioration. 

One of the drums observed on the video tape has imploded 

in the center. Four of the drums are clustered within a very 

94 Proceedings, 1991 EEZ Symposium on Mapping and Research 

short distance (100-200 m) of each other. The video system 

images an area of about 4 m2

. The fact that the camera 

randomly captured 5 drums in so small a field of view 

suggests that many more drums were grouped in the area. In 

fact, a cluster of 28 drums was found in a 30 X60 m area 

during the 1974 survey sponsored by EPA (Noshkin and 

others, 1978). Because we could not view the images in 

realtime , we could not do a detailed search in the vicinity of 

the five drums. The characteristics of the drums observed 

on the video tape and 35 mm film are consistent with the 

descriptions of the drums containing radioactive waste 

Figure 8. Preliminary interpretation of 1-km digital ~ 

mosaic of radioactive waste dumpsite area on upper 

continental slope. Numerals and letters identify locations of nongeologic targets interpreted as barrels. 

Dashed white lines (lower 1/4 of the image) trace examples of ridge crests, and the black arrow indicates an 

example of a canyon . 
Offshore Geology of the Gulf of the Farallones Region Project 95 
~ \ 

96 Proceedings, 1991 EEZ Symposium on Mapping and Research 
reported in the literature (for example, see Columbo and 

Kendig, 1990) and prove that they are part of the consignment of 47,800 containers of low-level radioactive waste. 

Maps of barrel distribution derived from the sonographs are 

being used to design sampling schemes to evaluate the risk 

that the levels of radioactivity may have on the biota and the 

environment. 

CONCLUSIONS 

Geologic inventory projects, such as the Offshore 

Geology of the Farallones Region, are particularly important in ocean areas offshore from major urban centers and 

protected marine sanctuaries where human activities have 

the most impact on the environment and where complex 

multiple-use decisions are necessary. The data collected 

during such projects aid in the resolution of geologic and 

oceanographic questions and critical social problems, such 

as hazardous waste management and pollution control. 

Many scientific surveying and sampling techniques are 

available to help solve environmental problems, but only a 

few could be discussed owing to the brevity of this article. 

Cooperative agency investigations, such as the Farallones 

Region project, are cost and time efficient. Where feasible, such partnerships should be used to address these 

important societal and scientific issues. 

ACKNOWLEDGMENTS 

The Farallones project is the result of close cooperation between many scientists and technicians at the USGS. 

William C. Schwab leads and coordinates the East Coast 

<1111111 Figure 9. Part of sidescan sonar mosaic obtained on the 

continental slope adjacent to the radioactive waste 

dumpsite. Small dots within the circled area are 55-gal 

drums. The black line from the photograph points to a 

particularly prominent cluster of barrels. The barrel 

illustrated is one of the barrels within the circled area, 

but it is not possible to attribute the photograph to a 

specific target (barrel) on the sonograph. 

team. The efficiency of the officers and crew of the R/V 

F arnella contributed significantly to the success of the 

project. 

REFERENCES CITED 

Chin, J.L., Rubin, D.M., Karl, H.A., Schwab, W.C., and 

Twichell, D.C., 1989, Cruise report for the Gulf of the 

Farallones cruise, F1-89-NC, F2-89-NC off the San Francisco Bay area, January 6 through 28, 1989: U.S. Geological 

Survey Open-file Report 89-317, 4 p. 

Colombo, P., and Kendig, M.W., 1990, Analysis and evaluation 

of a radioactive waste package retrieved from the Farallon 

Islands 900-meter disposal site: EPA Report 520/1-90-014, 

65 p. 

Danforth, W.C., O'Brien, T.F., and Schwab, W.C., 1991, 

Near-realtime mosaics from high-resolution side-scan sonar: 

Sea Technology, v. 32, no. 1, p. 54-59. 

Karl, H.A., Drake, D.E., and Schwab, W.C., 1990, Preliminary 

cruise report for Federal Agency cooperative cruises 

F?-90-NC and F8-90-NC, Farallon Escarpment, 19 July to 

3 August and 5 to 17 August, 1990: U.S. Geological Survey 

Administrative report, 8 p. 

Maher, N.M., Karl, H.A., Chin, J.L., and Schwab, W.C., 1991, 

Station locations and grain-size analysis of surficial sediment 

samples collected on the continental shelf, Gulf of the 

Farallones during cruise F2-89-NC, January 1989: U.S. 

Geological Survey Open-file Report 91-375A, 4 p. 

Noshkin, V.E., Wong, K.M., Jokela, T.A., Eagle, R.J., and 

Brunk, J.L., 1978, Radionuclides in the marine environment 

near the Farallon Islands: Lawrence Livermore Laboratory, 

University of California Report no. UCRL-52381, 17 p. 

Offshore Geology of the Gulf of the Farallones Region Project 97 
The Minerals Management Service's Implementation of 

the North American Datum of 1983 in the EEZ 

Alice R. Drew and Paul H. Rogers 

Minerals Management Service 

Abstract 

In December 1988, the United States officially 

adopted the North American Datum of 1983 as the new 

civilian horizontal datum for U.S. surveying and mapping 

activities. The Minerals Management Service is the Federal 

Agency responsible for developing and managing mineral 

resources on the Outer Continental Shelf from the State 

Seaward Boundary to the limit of the Exclusive Economic 

Zone. The Minerals Management Service began implementing the change to the new datum in 1991. The 

Agency's primary goals for its phased implementation are 

to develop a uniform cadastre throughout the Outer 

Continental Shelf and to remain conversant with its constituencies. 

WHAT IS NAD 83? 

Within the continental United States, horizontal positioning data (latitude, longitude, and plane coordinate 

systems) have been successively based on a series of 

different datums. The National Academy of Sciences concluded in 1971 that an adjustment of the North American 

Datum of 1927 (NAD 27) was needed to rectify inherent 

problems and provide scientific benefits. Three years later, 

the United States, Canada, Mexico, and Denmark (for 

Greenland) agreed to readjust the North American control 

survey network. Through a Federal Register (FR) Notice, 

the Department of Commerce published official notification 

of the establishment of a new datum on June 29, 1979 (44 

FR 37969). Creation of the North American Datum of 1983 

(NAD 83) was completed for the United States in 1986. 

NAD 27 is based on the Clark 1866 ellipsoid and a 

point of origin at Meades Ranch, Kans. In 1982, the United 

States and Canada decided to base all computations for 

NAD 83 on a geocentric reference ellipsoid. A reference 

ellipsoid is a geometric approximation of the Earth with 

specified dimensions and is associated with a geodetic 

reference system (GRS) or a geodetic datum. GRS 80 is the 

reference ellipsoid recommended by the International Association of Geodesists as the reference ellipsoid best defining 

98 Proceedings, 1991 EEZ Symposium on Mapping and Research 

the shape of the Earth for NAD 83. It was adopted by the 

International Union of Geodesy and Geophysics in 1979. 

NAD 83 does not have an initial point but is based on 600 

satellite Doppler stations. 

Remember that for both NAD 27 and NAD 83: (1) the 

same physical Earth surface is being referenced; (2) the 

physical points on the Earth's surface do not move when 

transformations are performed; and (3) the coordinate 

values do change when datum transformations are performed. It is the geographic referencing system that 

changes. 

WHY IS THE MINERALS MANAGEMENT 

SERVICE IMPLEMENTING NAD 83? 

Minerals Management Service (MMS) is the Federal 

Agency responsible for administering the development and 

management of mineral resources on the Outer Continental 

Shelf (OCS) in Federal waters. Federal jurisdiction extends 

from the State Seaward Boundary (SSB) to the limit of the 

Exclusive Economic Zone (EEZ). In general, the SSB is a 

mathematically computed boundary lying 3 nmi seaward of 

a baseline (usually the mean lower low-water coastline). 

Texas and the Gulf of Mexico coast of Florida are exceptions; they have historic SSB's out to 3 marine leagues. 

MMS also has responsibility for developing, depicting, and 

maintaining the OCS cadastre and its official coordinates 

and areal measurements. 

On December 6, 1988, the Federal Geodetic Control 

Committee (FGCC, is now a subcommittee of the Federal 

Geographic Data Committee) affirmed that NAD 83 was the 

official civilian horizontal datum for U.S. surveying and 

mapping activities performed or financed by the Federal 

Government. Further, Federal civilian agencies engaged in 

surveying and mapping activities were directed to convert 

from the contemporary datums being used (typically NAD 

27) to NAD 83 to the extent practical, legally allowable, 

and feasible (54 FR 25318, June 14, 1989). 

This directive is the primary reason that MMS converted to NAD 83. However, there are other considerations 
that have influenced MMS 's decision to convert. Almost all 

of the geographic source data used by MMS to define the 

baseline and compute (project) offshore boundaries are 

derived from nautical charts published by the National 

Ocean Service. When applicable, topographic maps published by the U.S. Geological Survey also are used. These 

agencies have developed or implemented NAD 27 to NAD 

83 conversion plans for their surveying and mapping 

products. These conversion plans schedule the surveyrelated data used by MMS to be converted to NAD 83 by 

approximately the year 2000. Because these products will 

be on NAD 83, MMS products also should reference that 

datum. 

From the inception of the offshore program until 

recently, one could confidently assume that datumdependent OCS cadastre coordinates and areal measurements referenced NAD 27. One also might expect to make 

the same assumption about datum-dependent information 

provided to the agency by industry. However, after 1960 a 

variety of navigation and positioning systems came into use 

on the OCS, some referencing other datums. Unless the 

datum is specifically identified, especially on post -1960 

datum-dependent coordinates and areal measurements, 

datum referencing could be to NAD 27, NAD 83, one of 

three World Geodetic Systems (WGS 60, WGS 72, or WGS 

84), or a local datum. Total conversion to one datum 

ensures compatibility and greatly reduces the need to 

transform data before it is exchanged among geographic 

data users in MMS, other Federal Agencies, States, and 

industry. 

MMS holds large quantities of engineering, geological, geophysical, oceanographic, and other scientific data 

that physically describe the water column, bottom, and 

sub bottom of the OCS. Data that are referenced to more 

than one datum will result in misinterpretations. Mixing of 

positioning data that are referenced to different datums must 

be avoided when exchanging or releasing engineering or 

scientific data so as not to corrupt other data bases. 

IMPLEMENTATION METHODS 

If switching from NAD 27 to NAD 83 were as easy as 

converting English measurements to metric or converting 

latitude and longitude to State Plane Coordinates, the 

conversion process for MMS would be relatively simple. 

Unfortunately, an exact transformation between NAD 27 

and NAD 83 does not exist. They differ systematically 

because of a change in the reference ellipsoid and randomly 

because of errors in computations, known distortions in 

NAD 27, and the inclusion of many new observations in the 

calculation of NAD 83. Also, almost all of the new 

observations were made with newer, more accurate instruments. 

There are two aspects to the MMS implementation of 

NAD 83: (1) the creation of a cadastre based on NAD 83 

and (2) the transformation of most of MMS' s existing data 

and boundaries from NAD 27 to NAD 83. 

The OCS cadastre has two main and independently 

developed parts-the projected offshore boundaries and the 

grid. Using a series of precise calculations, various offshore 

boundaries (SSB, EEZ, and so forth) are projected seaward 

from the baseline. 

The existing OCS cadastre, originally developed by 

the Bureau of Land Management, is based on NAD 27. It is 

not a single, consistent cadastre but represents the end 

product of an evolutionary process that resulted in five 

separate and distinct offshore cadastres. Three are based on 

State Plane Coordinate systems (California, Louisiana, and 

Texas), one on a variation of the Universal Transverse 

Mercator (UTM) grid system, and one on adherence to the 

parameters of the UTM grid. 

The NAD 83 cadastre of the offshore continental 

United States will be uniform and will strictly adhere to the 

definitive parameters of the UTM grid system. It will use 

the Geodetic Reference System of 1980 (GRS 80) as the 

reference ellipsoid. Where they are currently used, the 

English systems of measurement (feet and acres) will be 

replaced by the metric UTM grid system (meters and 

hectares). This will correct distortions and errors associated 

with some NAD 27 cadastres. 

The NAD 83 cadastre will not supersede the NAD 27 

cadastre. When a specific geographic area is converted to 

NAD 83, maintenance of the NAD 27 cadastre(s) for that 

area will cease. That is, when a geographic area is converted to NAD 83, a new cadastre based on NAD 83 will be 

created. Thereafter, the new cadastre will be maintained as 

needed. The old NAD 27 cadastre, which still will be 

needed for certain purposes, will be frozen in place and no 

longer maintained. 

As approved by the FGCC in December 1989 and 

published in 55 FR 32681, August 10, 1990, the Federal 

Government recognizes three procedures for obtaining 

NAD 83 coordinates for NAD 27 positions. In descending 

order of accuracy, these three methods are: 

• Resurvey the NAD 27 positions on NAD 83. 

• Recompute positions on NAD 83 using the original 

survey observations. 

• Transform NAD 27 coordinate values using the computer 

software package known as "N ADCON." 

For most purposes, MMS will use the third option to 

transform coordinates/positions between NAD 27 and NAD 

83. Through 55 FR 3493, February 1, 1990, MMS advised 

the public that the agency would use National Geodetic 

Survey (NGS)-developed software for this purpose. In 56 

FR 20020, May 1, 1991, MMS specifically advised the 

public that MMS would use the federally endorsed datum 

transformation computer software, NADCON, to convert 

existing NAD 27-based cadastre coordinates into NAD 83 

equivalents. 

The Minerals Management Service's Implementation of the North American Datum of 1983 in the EEZ 99 
NADCOM is a software package developed by 

NOAA's National Geodetic Survey for the transformation 

of coordinates between the NAD 27 and NAD 83 datums. 

NGS developed NADCON by using land-based geodetic 

data from its data base. Thus, the transformation package 

extrapolates the unknown offshore datum shifts from known 

onshore shifts. NADCOM is simple, cost effective, and 

rapid to use. NOAA Technical Memorandum NOS 

NGS-50, by Warren Dewhurst, may be consulted for 

technical information. It may be ordered from the National 

Geodetic Information Center (see page 101). 

The first version of NADCON to meet MMS's OCS 

needs offshore of Alaska and the conterminous United 

States is NADCON v2.00. The NGS officially released 

NADCON v2.00 in July 1991, and it has been adopted as 

the standard datum transformation software for MMS. 

MMS has affirmed that an OCS lessee's rights issued 

under a NAD 27legallease descriptions will continue to be 

protected as warranted under that description (55 FR 3493, 

February 1, 1990). This means that leases issued on a NAD 

27 cadastre will remain on that cadastre. The lease, however, must be portrayed on the NAD 83 cadastre to enable 

MMS to lease adjacent areas without overlap. The procedure for portraying NAD 27 leases on the NAD 83 cadastre 

and developing NAD 83 boundary equivalents and areal 

measurements for the leases can be complex: 

• "There is no rigorous mathematical method for transformation between such systems as NAD 27 and NAD 

83. . . . The most that we can achieve. . .is to make 

sure that the fixed coordinates in the new system remain 

the same as published and that the shapes of geometric 

figures within the network are preserved as much as 

possible. Beyond that all efforts are fruitless." (Vincenty, 

1988.) 

• "[NAD 27 and NAD 83] differ systematically because of 

a change in the reference ellipsoid and randomly because 

of imperfections in either system, known distortions in 

NAD 27, and the inclusion of many new measurements 

in the NAD 83 adjustment." (Graff, 1988.) 

• Both straight lines and arcs in NAD 27 become nonmathematically definable curves when transformed and portrayed in NAD 83. 

• The original NAD 27 radius between projected boundary 

intersections and the baseline is not maintained during 

the transformation process. (For example, a NAD 27 

radius of 5,556 m (3 nmi) will be 5,556 m plus or minus 

a small variable amount.) 

GOALS FOR MMS'S TRANSITION TO NAD 83 

MMS has two major concerns in portraying NAD 27 

leases on the NAD 83 cadastre: (1) The procedure to 

transform NAD 27 areal data to NAD 83 should be 

straightforward and simple to use, requiring neither special 

1 00 Proceedings, 1991 EEZ Symposium on Mapping and Research 

knowledge nor a significant amount of training for understanding and use. (2) Industry, coastal States, and other 

Federal Agencies must be able to replicate MMS computations without specialized software and (or) equipment. 

The best transformation of a line or arc is achieved by 

breaking the line or arc into small segments. The smaller the 

segments, the better the resulting line or arc definition after 

transformation. Three questions arise, however: (1) Into 

how many segments should a line or arc be broken? (2) 

What distance interval should be used for the line and arc 

segments? (3) What radius should be used for arcs? 

To simplify the transformation process for NAD 27 

leaseholds and to ensure that industry, coastal States, and 

others can replicate MMS computations, MMS will consider: 

• Straight lines on NAD 27leaseholds and boundaries to be 

straight lines on NAD 83. 

• Rhumb lines on NAD 27leaseholds and boundaries to be 

rhumb lines on NAD 83. 

• Geodesic lines on NAD 27 leaseholds and boundaries to 

be geodesic lines on NAD 83. 

• Arcs on NAD 27 leaseholds and boundaries to be arcs of 

the same radius on NAD 83. 

Slight discrepancies in the second or third decimal place 

may be found by not using some type of complex curve 

definition. 

IMPLEMENTATION TIMEFRAME 

MMS began implementation of NAD 83 in 1991. 

Conversion may require more than 10 yr to complete. On 

August 1, 1989, MMS published 54 FR 31737 stating that 

(1) the Agency will develop a NAD 83 implementation 

plan, (2) current offshore cadastre coordinates are referenced to NAD 27, and (3) future MMS cadastre-related 

documents will include a datum reference. The draft N AD 

83 implementation plan was published in 55 FR 48929, 

November 23, 1990. After a public comment period, the 

official plan, approved by the Director, MMS, was published in 56 FR 20020, May 1, 1991. 

The MMS implementation of NAD 83 is expected to 

be a long-term, dynamic process, requiring periodic 

updates. The implementation plan is a three-phase effort 

designed to minimize transition difficulties. 

Phase I provides time for each MMS regional office 

to identify, to the extent practical, the survey datum of 

existing data. Newly submitted data must be provided to 

MMS in the datum of observation and that datum identified. 

During Phase I, N AD 83 becomes the datum of preference 

to ensure compatibility with preexisting data. Non-NAD 

83-based information will be permitted, however, if the 

datum is explicitly identified. Leasing will be conducted on 

the NAD 27 cadastre. Phase I ends in 1993 with establishment of a full constellation of Global Positioning System 

(GPS) satellites. We expect that, at that time, GPS will be 
the dominant navigation and pos1t10ning system on the 

OCS, and it will be referenced to NAD 83. 

Phase II will solidify use of NAD 83 as the primary 

datum for MMS. Beginning with Phase II, MMS will 

require all data submitted by industry to be referenced to 

NAD 83. Leasing will continue to use the NAD 27 cadastre. 

Phase III will bring MMS into full compliance with 

NAD 83 usage and includes the establishment of the NAD 

83-based offshore cadastre. All leasing on the OCS will be 

conducted on NAD 27 until a regional office implements 

Phase III of the plan for a specific geographic area. 

Conversion of the first area to NAD 83 began in 

1991. Each regional office will determine when it has 

completed each phase and is ready to implement NAD 83 

for one or more specific geographic areas. Thus, NAD 83 

implementation varies within MMS. 

SHOULD THE OFFSHORE COMMUNITY 

IMPLEMENT NAD 83? 

The reasons that the offshore community should 

implement NAD 83 are similar to those that MMS faced. 

Use of N AD 83 will be greatly facilitated with satellite 

navigation and positioning systems such as GPS. Positions 

will be obtained directly on NAD 83. Thus, errors involved 

in transforming data will be eliminated. 

Conversion of existing geographic data ensures consistency. The decision also enhances efficiency because 

survey-related data from MMS and other Federal Agencies 

are currently in or are scheduled to be converted to NAD 83 

around the end of this century. Of the 22 States bordering 

the OCS, 16 have enacted legislation enabling NAD 83, 

two have legislation pending, three have corresponded with 

NGS recommending conversion, and one has not addressed 

the issue. 

It is critical that geographic data users be consistent in 

their data handling. If positional data referenced to one 

datum are plotted with respect to another, misplotting of 

points will occur with resultant misinterpretations of data 

and degradation of data-base confidence. Errors in plotting 

data points will be small in some areas, but larger in others. 

For example, wells could be plotted as drilled off an 

authorized lease, contours of subbottom structures could 

mistie, or paleontological data could be misplotted resulting 

in incorrect geological age determinations. Mixing of positioning data referenced to different datums also must be 

avoided when exchanging or releasing engineering or scientific data so as not to corrupt other data bases. 

Further, total conversion eliminates most of the need 

to transform data before the data are exchanged among 

MMS, other Federal Agencies, States, and industry. 

SUMMARY 

Within the United States, horizontal positioning data 

(latitude, longitude, and plane coordinate systems) have 

been successively based on a series of different datums. On 

December 6, 1988, the United States formally adopted 

NAD 83 as its official civilian horizontal datum. Conversion to NAD 83 will not affect existing leases; that is, the 

official descriptions will remain in NAD 27, and the areal 

extent of the leasehold will not be changed. Because these 

NAD 27 leases must be portrayed on the new NAD 83 

cadastre, lease coordinates, boundaries, and areas must be 

transformed. There are three official U.S. methods of 

transforming NAD 27 coordinates to NAD 83. Of these, 

MMS has chosen to use NADCON. Lease boundaries will 

be transformed by using simplifying assumptions. This will 

be done so that the procedure will be simple, straightforward, and not require special knowledge. 

It will take years for government agencies to provide 

all new geodetic data sheets, maps, and charts based on 

NAD 83. During this time of transition the highest potential 

exists for inadvertent mixing of NAD 27 and NAD 83 

position information and data. It is important to note that 

this time period has already started. The implementation 

plan developed by MMS attempts to make the conversion 

as smooth as possible. Datum conversion is a dynamic 

process, especially offshore; MMS is still learning about 

and assessing the ramifications associated with adopting 

NAD 83. 

FOR MORE INFORMATION 

Requests for the NADCON software should be 

directed to: 

National Geodetic Information Center 

N/CG 174, Rockwall Building, Room 24 

National Geodetic Survey, NOAA 

Rockville, MD 20852 

Telephone: 1-301-443-8631 

Questions and requests for information related to MMS 's 

implementation of NAD 83 should be directed to: 

Department of the Interior 

Minerals Management Service 

Mapping & Survey Group 

P.O. Box 25165, MS 4421 

Denver, CO 80225 

A TIN: Leland F. Thormahlen 

Telephone: 1-303-236-7050 

REFERENCES CITED 

Graff, D.R., 1988, Coordinate conversion from NAD 27 to NAD 

83: Journal of Surveying Engineering, v. 114, no. 3, p. 

125-130. 

Vincenty, T. , 1988, A note on approximate transformation of 

coordinates, surveying, and mapping: v. 48, no. 3, p. 

207-211. 

The Minerals Management Service's Implementation of the North American Datum of 1983 in the EEZ 1 01 
Dissemination of NOAA-NOS EEZ Multibeam 

Bathymetric Data 

Paul]. Grim 

National Oceanic and Atmospheric Administration 

Abstract 

A large amount of multibeam bathymetric sounding 

data has been and will continue to be collected by the 

National Oceanic and Atmospheric Administration in the 

U.S. Exclusive Economic Zone. The data collected include 

full resolution data (all the soundings) and derivatives of 

these data. Two types of gridded data (both available on 

disks for use on a personal computer) are being produced. One of the grids, with a grid point spacing of 250 

m, is used to make preliminary and published maps at a 

scale of 1:100,000 with a contour interval of 20 m. The 

standard map limits are 1° in longitude by 0.5° in latitude. 

Large three-dimensional plots (fishnet plots), combining 

the 250-m grids of six standard maps, are also being made. 

The grids and full resolution data (both in a digital format) 

and the maps are available to the public from several 

sources within NOAA. 

INTRODUCTION 

This paper complements the presentation given by 

Mills and Perry (this volume); they report and update the 

National Oceanic and Atmospheric Administration 

(NOAA) results and plans of its program to map the U.S. 

Exclusive Economic Zone (EEZ). The emphasis at this 

symposium is on the Pacific EEZ. This paper describes the 

nature of the data resulting from this program, as well as 

formats, products, and availability of both maps and digital 

data. 

Numerous publications give technical details on the 

multibeam systems used by NOAA (for example, see Farr, 

1980; Renard and Allenou, 1979). A description of how 

NOAA manages and processes the data, as well as details of 

how soundings are used to produce maps, is given by 

Herlihy and others ( 1988). A bibliography concerning the 

policy and science of EEZ mapping has been prepared by 

NOAA (1989). This bibliography includes numerous references to the complementary GLORIA sidescan data collected by the U.S. Geological Survey in the EEZ. 

1 02 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Because of the wealth of bathymetric detail revealed 

by NOAA's EEZ multibeam program, the dissemination of 

data was stringently controlled by the U.S. Navy prior to 

the spring of 1989. At that time, the Navy removed all 

restrictions on data dissemination with the exception of two 

areas: (1) The EEZ in the Pacific north of 46° N. (essentially 

the entire EEZ off the coast of the State of Washington) and 

(2) the Atlantic EEZ extending from Cape Romain, S.C., to 

Ft. Pierce, Fla. The data collected in these two areas from 

NOAA's EEZ multibeam program (but not from university 

multibeam research cruises) remain classified. 

Thus, it has been only slightly more than 2 yr that 

these data have been advertised and disseminated to the 

general public. Because of this short time period, the nature 

and availability of these multi beam data remain unknown to 

many potential users. 

One measure of the usefulness of the data is shown by 

scientific publications that use the data to interpret geologic 

features on the sea floor (for example, see Greene and 

others, 1989; Jackson and others, 1990; Bryant and others, 

1991). 

Much interest has been expressed at this symposium 

in NOAA's full resolution multi beam data, which is 

described as follows: A multibeam ship collects data in a 

swath along the sea floor. This swath is directly beneath the 

ship and normal to the ship's heading (fig. 1). Typically, 15 

or 16 soundings are obtained from the swath. For each 

sounding, a depth and a position are determined. A second 

swath of data is collected from the sea floor several seconds 

later (5 or 6 seconds is typical; the actual time between 

swaths depends mainly on water depth). This second swath 

produces a similar group of soundings that are offset from 

the soundings of the first swath, in a direction along the 

trackline of the ship. All soundings collected in this 

manner, for a complete bathymetric survey, make up a full 

resolution data set. The maps and gridded data, described in 

this paper, are based on only a small subset (selected 

soundings) of these full resolution data. 
SEABEAM OPERATION 

\ 

HIGH RESOLUTION 

FORMED BEAMS 

RECEIVED BEAMS 

TRANSMITTED BEAMS 

Figure 1. Sixteen soundings being collected from a single 

beam, on the sea floor, normal to the ship's heading. 

GENERAL CHARACTERISTICS OF EEZ 

SOUNDINGS 

NOAA has multibeam systems for obtaining soundings in both deep and shallow water. Two types of shallow 

water systems have been used. The first, no longer used, is 

the Bathymetric Swath Survey System (BSSS), which 

measured depths to 600 m. The currently used shallowwater system is HYDROCHART II, which is used in depths 

from 150 m to 1 ,000 m, although depths as shallow as 15 m 

have been measured. Both systems operate at 36 kHz and 

generate a swath on the sea floor with a nominal length of 

about 2.5 times the water depth. 

The SeaBeam system is the only deep-water system 

currently used by NOAA. It is used from the deepest parts 

of the U.S. EEZ to 1,000 m or 600 m, depending on which 

system is used in adjacent shallow water. SeaBeam operates 

at 12KHz and generates a swath measuring about 0. 7 times 

the water depth. 

At the present time, the only shallow water system 

used by NOAA in the Pacific has been the BSSS, and the 

only system used in the Atlantic and the Gulf of Mexico has 

been the HYDROCHART II, although it is anticipated that 

the latter system will be used in the Pacific in the future. 

Generally, no multibeam sounding data are collected 

in water depths less than about 150m. In order to complete 

a map containing such shallow water, older NOAA hydrographic survey data, of varying quality, are used. This is 

discussed by Matula (this volume). 

Most EEZ map areas measure 1 o in longitude by 0. 5° 

in latitude. In Alaskan waters, the east-west dimension is 

1.5° of longitude. However, there are exceptions to these 

standard map limits. These may occur when a map area is 

close to land, and it is judged that certain land features 

should be included in the map (the map limits would be 

expanded to include these features). It is also possible that 

in the future maps that are close to, or include the EEZ 

boundary, may not have these standard map limits. In some 

cases, a sea-floor feature, judged to be especially important 

environmentally or geologically, extends outside the U.S. 

EEZ boundary into international waters. In such cases, 

NOAA will enlarge its survey area to include the feature. 

This has been done in the Gulf of Mexico where NOAA has 

surveyed parts of the Sigsbee Escarpment extending seaward of the EEZ limit (Grim, 1990). 

The coverage of the sea floor using multibeam 

systems is 100 percent. The prevalent trend of the topography is known before a survey starts, and ship tracklines 

(mainscheme lines) are generally run parallel or subparallel 

to this trend. Swaths from adjacent, parallel mainscheme 

lines overlap by 10 percent or more. Crosslines, which 

generate about 5 percent of the total data collected, are run 

normal to the mainscheme lines and are used to verify 

soundings collected on the mainscheme lines. 

Sound velocity tables are developed from conductivity, temperature, and depth (CTD) data collected prior to 

surveying. Velocity corrections are applied to the raw 

sounding data. Daily expandable bathy thermograph (XBT) 

data are used to see if significant changes have occurred in 

the temperature of the water column. If this is the case, new 

CTD data are collected and used to derive a new sou~d 

velocity profile that is applied to the sounding data. 

Positions have been determined by satellite systems 

(STARFIX of John Chance, Inc., and differential Global 

Positioning System (GPS)) and shore-based systems such as 

ARGO and RA YDIST. Loran-C positioning is not used 

because of its limited accuracy (about 0.25 nmi or 463 m). 

All surveys are based on the 1983 North American Datum 

(NAD 83). 

The accuracy of depths and positions are judged to be 

well within the International Hydrographic Organization 

(IHO) standards of (1) 1 percent of actual depth (we believe 

that in most cases our depths are better than 0. 5 percent of 

true depth), and (2) within 50 m (based on the scale of our 

1: 100,000 scale maps) of true position. 

Dissemination of NOAA-NOS EEZ Multibeam Bathymetric Data 1 03 
PRELIMINARY AND PUBLISHED MAPS 

NOAA disseminates both preliminary and printed 

(published) maps. Both show identical bathymetric contour 

data except for shallow areas (less than 150 m depth) for 

some maps (see Matula, this volume). 

The purpose of disseminating preliminary maps is to 

make data available to the public before the map is 

published. The time between the availability of the preliminary map and the published map can be up to 1 yr or more 

depending on mapmaking priorities and other factors. Once 

a map is published, the preliminary map is no longer used. 

The 250-m grids and resulting contours for both types 

of maps are made from Contour Package System-1 

(CPS-1) (Radian Corporation) using a microVax III minicomputer. CPS-1 is also used to create the physiographic 

plots described below. 

Both types of maps have the following characteristics: (1) the scale is 1:100,000, (2) contours are in "corrected" meters, (3) the contour interval is 20 m, (4) the 

projection is Universal Transverse Mercator (UTM), and 

(5) loran-e lines (rates) are shown. 

Published maps differ from the preliminary maps as 

follows: 

(1) The preliminary maps generally do not show contours 

in water depths less than 150 m (it is possible that the 

published maps may also omit contours in shallow 

depths if the hydrographic data, from which these 

shallow contours are derived, are judged inadequate). 

(2) The published maps show, where available, lease block 

outlines provided by the Minerals Management Service. 

(3) The published maps are multicolored with tints of blue 

showing depth ranges. 

( 4) The published maps include at least one relatively small 

three-dimensional view of the whole map area (this 

three-dimensional view is derived from the same 250-m 

grid-described in the following test-used to generate 

map contours). 

(5) The published maps label both established names of 

sea-floor features and in many cases new names proposed by the National Ocean Service (NOS) or others 

for relatively large and distinctive features (features 

newly discovered or precisely defined for the first time 

as a result of the EEZ multibeam surveying. All names 

shown on the published maps have been approved by 

the U.S. Board on Geographic Names). 

PHYSIOGRAPHIC MAPS 

A new product we are now producing is a multicolored physiographic map consisting of a three-dimensional 

fishnet plot overlain by a generalized contour map with 

major sea-floor features labeled. This kind of map will 

1 04 Proceedings, 1991 EEZ Symposium on Mapping and Research 

commonly be made by combining the 250-m grids of six 

adjacent maps (two across and three down giving dimensions of 2° of longitude by 1.5° of latitude) into one large 

grid. To date, we have published two of these physiographic maps: one in the Gulf of Mexico and one off central 

California. A third, off northern Oregon, is in preparation. 

GRIDDED DATA 

Gridded data for a map area are produced from a 

small subset of the full resolution data. Typically, the 

number of full resolution soundings for a map area is about 

5 million to 10 million, the actual number being determined 

mainly by water depth. The subset used for gridding 

purposes is generally about 350,000 soundings to 400,000 

soundings with each sounding having an associated latitude 

and longitude with it. The subset (generally referenced as 

selected soundings) are randomly or almost randomly distributed over the map area. These are used to produce a 

250-m grid generally having about 80,000 grid points to 

100,000 grid points. A typical grid might have 400 columns 

and 230 rows. This grid is linked to the UTM map 

projection with coordinates of all x and y UTM grid points 

being evenly divisible by 250. 

This 250-m UTM grid is used to produce the contours 

shown on the preliminary and published maps (exceptions 

may exist for depths less than 150 m as discussed by 

Matula, this volume). 

This grid is also used to produce a geographic grid 

with a grid spacing of 15" in both latitude and longitude 

directions. This geographic grid consists of 241 columns 

and 121 rows for the standard map area. It is more 

conveniently manipulated by microcomputers since the 

number of grid points (29,161) is about one-third the 

number of points in the 250-m grid. For example, we are 

able to fit an entire geographic grid into SURFER software 

(Golden Software, Inc.), but the 250-m grid for a complete 

map is too large for SURFER. 

Figure 2 graphically shows how the 15" grid is 

derived from the 250-m grid. This geographic grid can be 

used to make small page-sized contour and threedimensional plots. An example, reduced in size to meet the 

requirements of this publication, is given as figure 3. Such 

a plot, made on a laser printer, does not provide all the 

detail of larger plots made with the 250-m grid, but it 

depicts the major features. 

Gridded data are disseminated for a single map area 

on a high-density diskette (3.5 in, 1.44 MB) or disk (5.25 

in, 1. 2 MB) for use on a personal computer (PC). Each 

disk/diskette contains both the 250-m grid and the geographic grid and a parameter file for each. The parameter 

files give information needed to interpret the grid files. In 

addition, a README file is included. All five files are 

written in ASCII. No software is provided. 
~ 15 SECONDS ~ 

• 

• 90" 11.000' 90" 10. 750' 

E: 

c 90" 11.125' 90" 10.875' 90" 10.625' 1/) 

• (\J 

• i • ... 

~ • • • 0 0 -.a 

... • • • ... 

• ... • . r412m--o0 . • 0 

• .. -463m ... • 

. 1 • 

• 

• ~ 0 

• • 

• • .. .. • 

FILE: GRIDFIG3 11/90 

Figure 2. This figure shows how a geographic grid, based 

on latitude and longitude coordinates, is derived from a 

Universal Transverse Mercator (UTM) grid, based on 

meters as coordinates. The UTM grid points, separated by 

250 m, are shown by small crosses. The relatively large 

open circles are the locations of the geographic grid 

points. Using a microcomputer (PC), the depth values of 

the geographic grid points are determined within each 

15" geographic square by taking the average of all UTM 

grid point depths that fall within the square. This is 

illustrated by the depth values in the heavily outlined 

square in the northeastern part of the figure. Here the 

Three pages of documentation, including text and 

graphics, are included with the gridded data. Two of these 

show the row and column arrangements of the two grids 

(the grids have different arrangements of rows and columns). A third page, created from the geographic file on the 

disk/diskette, shows the user how the contours should 

generally appear when the user produces a contour plot (fig. 

3). 

I 

'+ 

• 

T 

• 

I ... 31~ 3210 

• 

0 03200 ... 3220 • • 3190 

• ... ... 

0 0 

• • • 

• 

0 0~ 

• • 

I 

.. 

• 

l---

• 

• 

26" 45.625' ~ 

.. Ul 

0 

z 

0 

26" 45.500' ~ 

... 26" 45.375' 

26" 45.250' 

15 SECOND 

GRID POINT 

NORTH 

Ul 

lO 

..... 

250 METER GRID POINT (UTM) i 

1/4 MINUTE = 15 SECONDS 

depth of the geographic grid point centered in this 

square is 3,200 m. This is the average of the four UTM 

depth values in the same square. The number of UTM 

depths that go into determining the depth for a geographic grid point, in this example, varies from 1 to 4. In 

this figure the amount of skew between the two grids has 

been exaggerated to illustrate better how the geographic 

grid point depths are determined. The east-west separation of the geographic grid points varies with latitude. 

The example used (412 m) is for a latitude of about 27° N. 

The north-south separation (463) remains almost constant 

for all latitudes. 

FULL RESOLUTION DATA 

The full resolution data for a single map area typically 

totals about 5 to 10 millions soundings. The actual number 

is determined mainly by water depth but also by latitude of 

the map, average speed of the ship, and several other 

factors. 

Dissemination of NOAA-NOS EEZ Multibeam Bathymetric Data 105 
MITCHELL DOME MAP GULF OF MEXICO 

-89.0 -88.5 -88.0 

29.0 ~------~----~~--~--~~--~--~~~~~----~~=---?-~~~~~.-~~--~TT~~~ 29.0 

28.5 

-89.0 -88.5 

NOAA/NOS BATHYMETRY DEPTHS IN METERS 

RESULTS FROM MULTIBEAM MAPPING OF EXCLUSIVE ECONOMIC ZONE 

EST ABLJSHED NAMES 

NE'J NOAA/NOS NAMES A GULFPORT VALLEY B BRETON SPUR C REDFISH VALLEY 

D PASCAGOULA DOME E DORSEY CANYON F SOUNDER CANYON G HORN DOME 

H PETIT BOIS DOME I 'JHITING DOME J FARNELLA DOME K MITCHELL D[J.lE 

L BILOXI DOME M GLORIA DOME N MOBILE DOME 0 DAUPHIN DOME 

P HERONS MOUND Q BON SECOUR MOUND 

KILOMETERS 

0 10 20 

Figure 3. This is a "page-size" contour map derived from 

the 15" geographic grid using SURFER software on a 

personal computer with output to a laser printer. This type 

of plot is sent to data requestors, along with the corresponding grids on a floppy disk, to show how the data 

These data are important because they contain seafloor details, especially in relatively shallow water, that 

may not be contained in the 250-m grid used for making our 

maps (as already mentioned, the 250-m grid is derived from 

only a fraction of the full resolution data). Full resolution 

data can be used as input to processing and display 

techniques differing from those used by NOAA. 

Full resolution data, as defined here, include sounding data judged to meet the IHO standards for depth and 

position. This means that some of the collected data have 

been rejected because they are artifacts of the data collection process (de Moustier, 1986) or are data collected when 

the ship makes tight turns. Typically, these rejected data 

amount to 1 percent to 2 percent or less of the total data 

collected and are saved in a cull file. A number of 

1 06 Proceedings, 1991 EEZ Symposium on Mapping and Research 

30 40 50 

should appear when plotted. In this example, a salt 

canopy with circular to lobate salt features is readily 

apparent in the eastern half of the plot (see Jackson and 

others, 1990). 

corrections have been applied to the full resolution data in 

order to make the data as accurate as possible. Several of 

these are corrections for the velocity of sound in seawater 

(including refraction of nonvertical beams), depth of the 

transducer (draft correction), tidal corrections (for the 

shallow water multibeam systems only), and a correction 

for the offset of the transducers from the positioning 

antenna. All corrections applied are listed in a separate 

ASCII header file. 

The format of the full resolution data (NOAA refers 

to this format as the SBO format) is the same as the 

University of Rhode Island (URI) format. Data are written 

in a binary format on a micro Vax III minicomputer running 

under virtual memory system. The data are not in an ASCII 

format. 
~ ~ . ,._ 

~· l]@)l(~}!.if - - ~ ~ ~ 

'"":i'"' ... ~ ~ ' 

;_§!Lqs (;L~Jut®]} m& 

l ~~~i~t c -

k.. • - ·- • • • -- -. -· --- .. -

The four main data components of the SBO-URI data 

are illustrated in figure 4 for soundings generated from a 

single SeaBeam swath. In this figure, there are 15 soundings: 1 center beam sounding and 7 starboard and 7 portside 

soundings. The SBO-URI format contains four required 

types of data: ( 1) the values of the soundings in metersshown in the figure; (2) the crosstrack distances (the 

distance in meters of each sounding from the center sounding)-not shown in the figure; (3) the heading of the ship; 

and (4) the latitude and longitude of the center-beam 

sounding. Thus, 14 of the soundings do not have positions 

explicitly given in the full resolution data set. These 

soundings must be determined by user-supplied software. In 

~Figure 4. This shows graphically the content of the 

SBO-URI full resolution data. The numbers are soundings in meters. Each has a crosstrack distance (not 

shown) measured horizontally from the center beam 

sounding. See text and figure 5 . 

. SBO or .SBM DATA FORMAT 

(from program EXAMMERG Listing - Binary Format) 

GMT Longitude *Pitch Gyrocompass 

(HH:MM:SS) (DD::MM::SS) Heading 

Julian Latitude Ship ***CBTime 

D~ay ~(DD::MM::SS) S~peed *~*pll ~ Year .,,. ,, .,, ,, J 

l19a9lo7siLo9:3o:2sl 2611.1777ll-o91 o.9412l o.o o.o o 1816.3 o.oo 

0 0 238 7 0 2393 2396 2403 2404 2414,2424 1427 2434 2448 2449 2454 2453 0 0 0 

0 0 -802 0 -564 -449 -336 -223 -111 f 112 226 342 458 578 699 0 0 0 l 

Vertical Crosstrack 

Beam Distances 

(m) 

-=port; 

* = Pitch is always zero for SeaBeam which is beam steered. 

** = Port/stbd flag used for Hydrochart ll to indicate which of 19 slots holds the vertical beam 

and to indicate whether a ping is from the port or starboard array. 

***=Echo processor time-of-ping in seconds relative to the beginning of the Julian Day. 

Figure 5. SBO/URI format for full resolution data. See figure 4. 

Dissemination of NOAA-NOS EEZ Multibeam Bathymetric Data 107 
FULL RESOLUTION DATA 

DISSEMINATED BY SURVEYS 

RELATIVELY DEEP WATER 

Figure 6. Complete standard map composed of three 

surveys. All full resolution data sets are associated with a 

single survey. Thus, to look at all the soundings in area A, 

one would need to obtain only the full resolution data set 

corresponding to survey 800196 in this example. 

addition, several other parameters for the full resolution 

data, such as times and dates, are included in a full 

resolution data set. The format (the SBO or URI format) of 

the full-resolution soundings is shown in figure 5. 

Unlike the maps and gridded data described previously, the full resolution data sets are linked to individual 

surveys that are combined to produce a complete map. This 

is illustrated in figure 6 where a typical survey pattern for a 

single map, in waters greater than about 1,500 m depth, is 

shown. The full resolution data in this figure would be 

contained in three separate data sets, each associated with 

one of the three surveys shown. 

DATA DISSEMINATION 

Figure 7 shows the current method of disseminating 

EEZ multibeam data from NOAA. The data are sent to the 

public from NOS in the Washington D.C., area or from the 

National Geophysical Data Center (NGDC) in Boulder, 

Colo. 

Preliminary maps and gridded data sets along with 

general information (including index maps showing the 

status and availability of all maps and grids plus the 

addresses and phone numbers to contact) are available from 

the NOS Ocean Mapping Section in Rockville, Md. The 

cost of a map is $10, and the cost of a disk/diskette is $20. 

Printed (published) maps are available from the NOS 

distribution center in Riverdale, Md. As with the preliminary maps, the cost is $10 per map. All maps (preliminary 

and published) are sent in a mailing tube. Folded maps are 

not available. 

1 08 Proceedings, 1991 EEZ Symposium on Mapping and Research 

DISSEMINATION 

EEZ MULTIBEAM 

MAGNETIC TAPE 

MAP GRIDS 

INFORMATION 

PRELIMINARY MAPS 

ROCKVILLE, MD 

!PUBLISHED MAPsiTUBE. 

RIVERDALE, MD 

OF 

DATA 

FILE EEZDISEM 

Figure 7. Data flow of NOM's multibeam EEZ data and 

data products. The gridded data will be disseminated from 

NGDC in the future instead of from NOS as indicated in 

this diagram. 

Full resolution data will be sent from NOS to NGDC, 

where they will be made available to the public. This 

process is just starting (nine HYDROCHART II surveys 

from the Gulf of Mexico have recently been sent to NGDC). 

NGDC will advertise the availability of these data in the 

near future. 

ADDITIONAL INFORMATION 

Additional information on NOAA's program to map 

the U.S. EEZ can be obtained from: 

Ocean Mapping Section, Code N/CG224 

NOAA/NOS Rockville, MD 20852 

Phone 301 443-8251 

REFERENCES CITED 

Bryant, W.R., Simmons, G.R., and Grim, P.J., 1991, The 

morphology and evolution of basins on the continental slope 

northwest Gulf of Mexico, Transactions: Gulf Coast Association of Geological Societies, v. XL. 

de Moustier, C., and Kleinrock, M.C., 1986, Bathymetric artifacts in SeaBeam data-How to recognize them and what 

causes them: Journal of Geophysical Research, v. 91, no. B3, 

p. 3407-3424. 

Farr, H.K., 1980, Multibeam bathymetric Sonar-SEABEAM 

and HYDRO CHART: Marine Geodesy, v. 4, no. 2. 

Greene, H.G., Stubblefield, W.L., and Theberge, A.E., Jr., 

1989, Geology of the Monterey Submarine Canyon system 
and adjacent areas, offshore Central California, U.S. Geological Survey Open-File Report 89-221, 33p. 

Grim, P.J., 1990, Results of multibeam swath surveying by 

NOAA in the Gulf of Mexico Exclusive Economic Zone, 

Transactions: Gulf Coast Association of Geological Societies, v. XL. 

Herlihy, D.R., Matula, S.P., and Andreasen, C., 1988, Swath 

mapping data management within the National Oceanic and 

Atmospheric Administration: International Hydrographic 

Review, v. LXV. no. 2. 

Jackson, M.P.A., Cornelius, R.R., Craig, C.H., Gansser, A., 

Stocklin, J., and Talbot, C.J., 1990, Salt diapirs ofthe Great 

Kavir, Central Iran: Geological Society of America, Memoir 

177. 

NOAA, 1989, Policy and science of Exclusive Economic Zone 

mapping: bibliography, U.S. Dept. Commerce, NOAA, 

NESDIS, National Oceanographic Data Center, Washington 

D.C. 

Renard, V., and Allenou, J.P., 1979, SeaBeam-Multi-beam 

echo-sounding, in Jean Charcot, Description, evaluation and 

first results: International Hydrographic Review. v. LVI, 

no. 1. 

Dissemination of NOAA-NOS EEZ Multibeam Bathymetric Data 109 
Application of Drainage Extraction to NOAA Gridded 

Bathymetry of the U.S. Continental Margin 

Lincoln F. Pratson and William B.F. Ryan 

Lamont-Doherty Geological Observatory, of Columbia University 

ABSTRACT 

Drainage-extraction algorithms are applied to gridded bathymetry of the U.S. continental margin. The algorithms are shown to be extremely useful in mapping 

submarine canyons, deep-sea channels, and the areas of 

the sea floor these systems drain. Subjective parameters 

limit the accuracy of the information the algorithms derive 

from gridded bathymetry. However, as long as these 

limitations are known, there are a number of potential 

ways drainage extraction can be used to analyze gridded 

bathymetry. 

INTRODUCTION 

The Federal Government's endeavor to map the U.S. 

Exclusive Economic Zone (EEZ) promises to yield important scientific results for years to come. Because of this 

undertaking, 100 percent bathymetric coverage of hundreds 

of thousands of square kilometers of the U.S. continental 

margin, extending from coastlines to the 200-mi limit, is 

revealing sea-floor terrains never before seen. A direct 

benefit is that the morphology of economically important 

but geologically poorly understood regions, such as the salt 

province in the Gulf of Mexico, can now be studied in 

detail. 

Likewise, the digital nature of the data being collected greatly improves the ability of scientists to analyze 

quantitatively the morphology of the U.S. continental 

margin. Measurements derived from these analyses can lead 

to better understanding of the processes by which the 

margin is shaped. 

One such analysis is the study of submarine drainage 

systems. Submarine drainage systems are defined here as 

the networks of submarine canyons and channels through 

which sediments are transported to the deep sea. These 

systems have many morphologic similarities with drainage 

systems on land (Hesse, 1989; Schlee and Robb, 1991) but 

are the consequence of erosion by subaqueous sediment 

flows rather than running water. The comprehensive 

11 0 Proceedings, 1991 EEZ Symposium on Mapping and Research 

bathymetry of the U.S. continental margin being compiled 

by the National Oceanic and Atmospheric Administration 

(NOAA) now makes it possible to completely map whole 

submarine drainage systems. 

Recently, a sequence of algorithms has been developed to extract channel networks and drainage areas from 

digital elevation models (Moore and others, 1991). Up to 

now, these algorithms have principally been used in the 

hydrologic and geomorphic study of drainage systems on 

land. However, the algorithms are data independent, and 

they can be applied to any rectangular gridded data set. 

The purpose of this paper is to present the potential 

for using drainage-extraction algorithms to analyze gridded 

bathymetry. The algorithms used in this study were derived 

from O'Callaghan and Mark (1984) and Jenson and Dominique (1988). To illustrate how the algorithms work, the 

routines are applied to gridded NOAA bathymetry of the 

continental margin offshore Monterey, Calif. This analysis 

also serves to highlight some of the algorithms' limitations. 

With these limitations in mind, several examples are presented as to how drainage-extraction algorithms can be used 

for both applied and academic analyses of sea-floor morphology. 

EXAMPLE BATHYMETRY 

Bathymetry off California was collected by NOAA as 

part of the Federal Government's initiative to map the EEZ. 

Under this initiative, NOAA has begun the job of providing 

complete bathymetric coverage of the EEZ. Several large 

surveys have now been completed, and selected map areas 

of these surveys are available to the public. 

One such region is the California margin offshore 

Monterey (fig. 1A). In this region, six contiguous map areas 

1 o of longitude by 0.5° of latitude have been gridded. Each 

grid is based on roughly 300,000 soundings selected from a 

total of 5-10 million raw soundings (Grim, 1991). The grid 

projections are in Universal Transverse Mercator coordinates, and have a grid-node spacing of 250 m. Since the 
grids share a common central longitude and adjacent grids 

overlap by 1 km to 2 km, a composite grid can be 

constructed by mosaicking the individual grids together. 

The composite grid of the California data set is shown in 

figure lB. 

Extraction Technique 

To extract channel networks and drainage areas from 

gridded bathymetry four general steps are followed: (1) 

determine flow directions, (2) compute flow accumulations, (3) extract drainage networks, and (4) delineate 

drainage areas. 

The first step is to assign each cell in the grid a flow 

direction. A cell's flow direction is determined by selecting 

one of the eight neighboring cells that has the greatest 

distance-weighted drop in elevation. Theoretically, flow 

direction is the direction fluid would flow out of a grid cell 

and thus should point downslope. However, since flow 

direction is restricted to being toward one of the eight 

neighbors, a cell's flow direction is an approximation of the 

downslope direction. Flow directions determined for the 

portion of the California data set surrounding Monterey 

Canyon are shown in the upper right of figure 2. 

By following the flow directions, it is possible to sum 

the number of "upslope" cells that end up directing flow to 

each cell in the grid. This sum is a cell's flow accumulation 

value and is somewhat analogous to the amount of discharge that can enter a cell. Flow accumulations derived 

from flow directions are shown in the lower right of figure 

2. In this figure, cells with increasing flow accumulation 

change shade from black (zero flow accumulation) to white 

(maximum flow accumulation). 

Flow accumulations can be used to extract drainage 

networks. This is done by specifying a flow accumulation 

threshold. All cells that have flow accumulations that 

exceed the threshold constitute part of the drainage network. Cells with flow accumulations equal to or less than 

the threshold are considered part of the interfluves that 

separate individual channels of which the network is composed. If the threshold is raised, the intricacy of the 

drainage network decreases. If the threshold is lowered, the 

intricacy of the drainage network increases. A drainage 

network extracted from the flow accumulations using a 

threshold of 100 cells is shown in the lower left of figure 2. 

The final step is drainage area delineation and is 

again accomplished by following the grid's flow directions. 

Drainage areas are delineated by simply grouping all the 

cells that direct flow to the designated drainage area starter 

cells. Those cells that do not direct flow to a starter cell are 

considered to be outside the starter cell's drainage area. 

Criteria for selecting starter cells can be tailored to the 

user's interest. For instance, if the drainage area of depressions within a data set is desired, starter cells would be 

those cells lower than their eight surrounding neighbors. 

Because these cells, or pits, lack a downslope flow direction, they can be automatically flagged with a unique 

number, which in turn can be used to group all the 

upslope cells to which the pit cells are linked by flow 

directions. 

Subjective Limitations 

Although drainage extraction can provide a significant amount of information on submarine drainage systems, 

not all information may be accurate. Such inaccuracies are 

often the consequence of subjectivities inherent in the 

algorithms. 

For instance, the complexity of the drainage network 

extracted from a bathymetric grid is determined by the flow 

accumulation threshold used to extract the network. This 

means that not all the channels mapped in the network are 

necessarily eroded channels, nor are all the eroded channels 

mapped. Figure 3 shows drainage extracted from the 

California bathymetry around Big Sur Canyon using flow 

accumulation thresholds of 50 cells (fig. 3, upper right) and 

500 cells (fig. 3, lower right). The network extracted using 

a threshold of 50 cells has several perfectly straight tributaries. These tributaries are probably not true erosional 

channels. More likely, they are uneroded slopes that lead 

into the canyon. In the network extracted using a threshold 

of 500 cells, these "artificial" tributaries are not mapped, 

but real tributaries are not mapped either. 

Ideally, where the true drainage network is being 

sought, the flow accumulation threshold should be adjusted 

to extract as many channels as can be resolved by the data. 

However, accurately mapping drainage systems has been a 

problem confronting geomorphologists for centuries. This 

same problem now confronts users of drainage extraction 

algorithms who like geomorphologists using contour maps 

must make a judgment call as to how intricate the drainage 

network they are mapping really is. 

Another step that introduces subjectivity into drainage extraction is dealing with bathymetric depressions. 

Normally gridded data is preconditioned to infill all depressions before applying the algorithms. If depressions are not 

infilled, then the drainage network extracted is segmented. 

This segmentation occurs because flow directions of cells 

surrounding a depression are directed into the depression. 

Thus, depressions in a canyon or channel break the continuous link of flow directions that mark its thalweg. Segmentation is particularly acute in areas where variations in local 

relief, either real or gridding artifacts, exceed changes in 

regional relief (abyssal plains). 

The justification for infilling grid depressions is that 

fluid flow, upon encountering a depression, will infill the 

depression up to the lowest elevation along the depression's 

rim and then exit. This assumption is fine for areas such as 

the California margin, where materials documented at the 

distal end of the Monterey Fan indicate sediment flows have 

Application of Drainage Extraction to NOAA Gridded Bathymetry of the U.S. Continental Margin 111 
surmounted any channel-thalweg depressions. However, 

where large sea-floor depressions occur, infilling of depressions results in the extraction of an artificial drainage 

network. 

An example is the interslope basins in the salt 

province of the Gulf of Mexico, several of which are shown 

in the upper left of figure 3. Some of the basins in this 

province exceed 500 m in depth. Many are presently 

isolated from sediment input from the margin, as well as 

from one another. Normal preconditioning in which all 

depressions are infilled results in the extraction of a false 

drainage network that leads from one depression to another 

(center left, fig. 3). 

To correct for this inadequacy, an option has been 

added to the preconditioning phase allowing the user to 

specify a relief threshold. Relief in this instance is defined 

as the difference in elevation between the bottom of the 

depression and the lowest point along the depression's rim. 

Depressions with relief less than or equal to the threshold 

are filled in, while those with relief greater than the 

threshold are left alone. In the case of the Gulf of Mexico 

data set, a relief threshold of 10m results in the extraction 

of internal drainage (lower left, fig. 4), which more 

accurately reflects the present isolation of the interslope 

basins. 

Like the flow accumulation threshold used to extract 

drainage networks, the relief threshold is a subjective 

choice made by the user. Ideally, the threshold should be 

chosen so that only those depressions created by the 

gridding process, or shallow enough to be breached by 

sediment flows, are infilled. 

Potential Applications 

Keeping the limitations of drainage extraction in 

mind, there are a number of ways these algorithms can be 

used to analyze gridded bathymetry for both applied and 

academic interests in sea-floor morphology. In terms of 

applied research, one of the benefits of drainage extraction 

is that, in addition to mapping drainage networks, you can 

also map drainage divides. By setting the flow accumulation threshold equal to zero, it is possible to isolate all grid 

cells that do not receive input from other cells (upper left, 

fig. 4). In other words, these cells are relative topographic 

highs. Such a map could be particularly useful in charting 

locations that minimize risks to offshore communication 

cables, hazardous waste disposal sites, or piping from 

marine oil production platforms. 

The drainage extracted from gridded bathymetry can 

also be used to help interpret sidescan sonar imagery from 

the same region (upper right, fig. 4). If drainage extracted 

from the bathymetry is overlain onto the sidescan sonar 

imagery, it is possible to map sediment pathways hard to 

detect in the sidescan imagery alone. 

112 Proceedings, 1991 EEZ Symposium on Mapping and Research 

A 

Figure 1A. Location map of the gridded NOM bathymetry off California used in this paper. 

By merging gridded bathymetry with gridded topography, drainage extraction algorithms can be used to map 

drainage areas and sediment pathways from land to sea 

(lower right, fig. 4). With such information, source areas of 

deep-sea depocenters, such as submarine fans, can be 

quantified. Additionally, if deep-sea sedimentation rates 

and denudation rates on land are known, it should be 

possible to come up with an estimate as to how erosion of 

a continental margin balances against the development of a 

submarine fan. 

A study presently underway is a geomorphic analysis 

of submarine drainage systems. Geomorphic measurements 

of submarine drainage systems extracted from gridded 

bathymetry are presently being compared with measurements of drainage systems on land. The hope is that, through 

this comparison, factors known to influence the development drainage on land will lead to an understanding of the 

factors that influence drainage development beneath the 

sea. 

For example, observations have repeatedly verified 

that drainage basins on land obey a series of morphometric 

relations, referred to as Horton's Laws (Ritter, 1986). 

To test whether or not submarine drainage systems obey 

these same relations, channel networks need to be ordered 
B 

Figure 1 B. Composite of the California continental margin bathymetry offshore Monterey. False 

illumination is from the west. Depths range from 1 m in Monterey Bay to - 4,000 m at the 

seawardmost edge of the grid . 

according to the Harton-Strahler ordering scheme (Strahler, 

1952), and the areas of the sea floor they drain need to be 

defined. 

Several fourth-order basins were defined according to 

these criteria in the NOAA bathymetry of the California 

continental margin . The number, lengths, and slopes of the 

channels within each basin were tallied to determine how 

closely the basins followed several of the relations derived 

by Horton (1945). 

One such measurement is the bifurcation ratio, which 

is expressed as the number of channels of a given order 

divided by the number of channels of the next higher order. 

If the number of channels of each order is plotted on a 

semilog plot, the points should follow a relatively straight 

line-the slope of which is the logarithm of the bifurcation 

ratio. Such a plot provides a graphic measure of how well 

the bifurcation ratio holds for the range of ordered channels 

within a basin. In the case of the submarine drainage basins 

off California, a representative example of which is shown 

in the lower left of figure 4, this relation is consistent over 

all orders. This consistency implies that, within each drainage basin, the processes of nature have adhered to a 

relatively conformable set of guidelines for drainage development. 

Application of Drainage Extraction to NOAA Gridded Bathymetry of the U.S. Continental Margin 113 
Figure 2. Upper left, Blow up of the bathymetry surrounding Monterey Canyon. Upper right, Flow directions for the 

bathymetry. Eight shades of gray represent the eight 

possible directions of flow, beginning with black, which 

points toward the northeast, and proceeding clockwise 

to white, which points toward the north. Lower right, 

Flow accumulations for the bathymetry. Cells with increasing flow accumulations change color from black (lowest) 

to white (highest). Lower left, Drainage network extracted 

using a flow accumulation threshold of 100 cells. 

Figure 3. Upper left, NOM bathymetry of the salt province in the Gulf of Mexico showing several interslope basins ~ 

(dark gray). False illumination is from the west. Center left, Drainage network extracted when the basins are 

completely infilled. Lower left, Drainage network extracted when only depressions less than or equal to 10m deep are 

infilled. Upper right, Drainage extracted from bathymetry surrounding Big Sur Canyon off California using a flow 

accumulation threshold of SO cells. Note straight, "artificial" channels. Lower right, Drainage extracted using a 

threshold of 500 cells. Note that while the "artificial" channels have been removed, more sinuous channels have also 

been removed. 

114 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Application of Drainage Extraction to NOAA Gridded Bathymetry of the U.S. Continental Margin 115 
BIFURCATION RATIO 

Fourth-Order Submarine Drainage Basin 

NOAA Bathymetry Offshore Monterey, CA 

Drainage Extraction Threshold = 500 cells 

-

Vl 

..::1 

~ 

z Correlation Coefficient = 0.984 

z 

< 

u = .... 1 

Q 

~ 

~ 

=:I 

~ ;:;J 

z 

'-" 

Q 

ell 0 1 2 3 4 5 

- CHANNEL ORDER 

Figure 4. Upper left, Drainage extracted from bathymetry 

surrounding the head of Monterey Canyon using a flow 

accumulation threshold of 0 cells. Gray areas are topographic highs or ridges. Upper right, Drainage extracted 

for bathymetry surrounding the Shepard Meander Loop 

on the Monterey Fan (white cells) overlain on 30-kHz 

sidescan sonar from the same area . Lower right, NOAA 

bathymetry merged with USGS 30" gridded topography of 

Aside from illustrating the similarity of submarine 

drainage basins to land drainage basins, such measurements 

provide geologic information as well. In the case of the 

measurement above , on land, a bifurcation ratio in excess of 

116 Proceedings, 1991 EEZ Symposium on Mapping and Research 

California. False illumination is from the west. Deep 

incisions in the lower left of the figure are the submarine 

canyons off Monterey California. The highs in the upper 

right of the figure are the Coastal Mountain Ranges. Lower 

left, Graph showing the bifurcation ratio of ordered channels within a fourth-order drainage basin extracted from 

the NOAA bathymetry off California. 

10 indicates pronounced structural control of the drainage 

system, encouraging development of long, narrow drainage 

basins (Chorley and others, 1984). Bifurcation ratios of 

between 3 to 5 are characteristic of dendritic drainage 
networks formed in homogeneous rocks. The bifurcation 

ratio of the drainage areas on the Monterey Fan are about 2, 

narrowing the best land analogs for these systems to 

drainage networks developed in alluvium. 

SUMMARY 

A sequence of algorithms has been written to map 

submarine channel networks and drainage areas in gridded 

bathymetry. These algorithms are collectively referred to as 

drainage extraction and are based on the approach developed by investigators using digital elevation models to 

study drainage systems on land. The algorithms are shown 

to be not perfect. Algorithm parameters introduce an 

inherent subjectivity to the drainage information extracted 

from gridded bathymetry. However, drainage extraction 

remains a powerful tool for analyzing submarine morphology, particularly continental margin morphology, which is 

characterized by networks of submarine canyons and deepsea channels. The potential of drainage extraction is illustrated by several possible applications of algorithms for use 

in both applied and academic analysis of gridded bathymetry. 

ACKNOWLEDGMENTS 

This project was made possible by help from the 

USGS-NOAA Joint Office for Mapping and Research, with 

special thanks owed to Millington Lockwood and Paul 

Grim. Support provided by the Office of Naval Research 

(Contract N00014-87-K0204-Scope BMS) and the 

National Science Foundation (Grant OCE-89-12241). 

REFERENCES CITED 

Chorley, R.J., Schumm, S.A., and Sugden, D.E., 1984, Geomorphology: Methuen and Co., Ltd., New York, N.Y. 

Grim, P.J., 1991, Disseminating NOAA/NOS EEZ multibeam 

bathymetric data, in Working Together in the Pacific EEZ: 

NOAA/USGS workshop, Nov. 5-7, 1991, Portland, Oreg., 

program abstract. 

Hesse, R., 1989, Drainage systems associated with mid-ocean 

changes and submarine hazards-Alternative to submarine 

fan depositional systems: Geology, v. 17, p. 1148-1151. 

Horton, R.E., 1945, Erosional development of streams and their 

drainage basins-Hydrophysical approach to quantitative 

morphology: Geological Society of America Bulletin, v. 56, 

p. 275. 

Jenson, S.K., and Dominique, J.O., 1988, Extracting topographic 

structure from digital elevation data for geographic information system analysis: Photogrammetric Engineering and 

Remote Sensing, v. 54, no. 11, p. 1593-1600. 

Moore, I.D., Grayson, R.B., and Ladson, A.R., 1991, Digital 

terrain modelling; a review of hydrologic, geomorphological 

and biological applications: Hydrological Processes, v. 5, 

p. 3-30. 

O'Callaghan, J.F., and Mark, D.M., 1984, The extraction of 

drainage networks from digital elevation data: Computer 

Vision, Graphics and Image Processing, v. 28, p. 323-344. 

Ritter, D.F., 1986, Process geomorphology (2d ed.): Dubuque, 

Iowa, Wm.C. Brown Pub., 579 p. 

Schlee, J.S., and Robb, J.M., 1991, Submarine processes of the 

middle Atlantic continental rise based on GLORIA imagery: 

GSA Bulletin, v. 103, p. 1090-1103 

Strahler, A.N., 1952, Hypsometric (area-altitude) analysis of 

erosional topography: Geological Society of America Bulletin, v. 63, p. 1117-42. 

Application of Drainage Extraction to NOAA Gridded Bathymetry of the U.S. Continental Margin 117 
Bridging the Gap-Creating Nearshore Bathymetric Maps 

from Multibeam Swath Sonar Systems and Conventional 

Hydrographic Data 

Stephen P. Matu Ia 

National Oceanic and Atmospheric Administration 

Abstract 

The main focus of the National Ocean Service Ocean 

Mapping Program has been to collect highly accurate and 

precisely navigated digital bathymetric data in depths 

deeper than 150 m. Depths of these magnitudes may only 

partially cover continental shelf regions, which are of 

particular interest to the mapping and other scientific 

communities. Thus, whenever possible, additional inshore data sources are incorporated to supplement the 

multibeam survey data and to provide a complete map 

depiction. This paper discusses the current techniques 

used in integrating modern digital multibeam swath sonar 

data with additional inshore sources, conversion of supplemental digital and nondigital hydrographic data, methods of incorporating cartographically interpreted contour 

lines derived from hand digitization, raster scanning or 

vectorization, and outputs in both digital and analog 

forms. 

INTRODUCTION 

In the past 7 yr, National Oceanic and Atmospheric 

Administration vessels have collected 106,000 nmi2 of 

digital multibeam swath bathymetric data in waters primarily deeper than 150 m. These data have resulted in the 

production of 24 high quality, deep-water bathymetric maps 

that have been compiled exclusively from multibeam data. 

Although modem multibeam surveys continue to 

collect data and expand knowledge along the relatively 

unexplored continental slope areas, other parts of the 

continental margins are also becoming of increasing interest. In fact, requests for information in the nearshore 

regions by scientists in State and local government, academic institutions, and commerce enterprises have grown 

for the past several years. One of the conclusions in a report 

issued by the National Research Council, Commission on 

Engineering and Technical Systems, Marine Board (October 1991 , p. 24), was that ". . . the primary interest 

118 Proceedings, 1991 EEZ Symposium on Mapping and Research 

expressed by states and industries are in the shallow 

nearshore regions." As a result, in order to attempt to 

address these needs, continued efforts will be made to 

assemble inshore bathymetric maps which must be constructed of both offshore multibeam data and inshore 

hydrographic information. 

MULTIBEAM DATA PROCESSING 

Over the course of the past several years, methods 

have been developed to process multibeam data efficiently 

and to produce a usable product. The schematic in figure 1 

gives a brief end-to-end overview of the current structure 

employed in creating bathymetric maps. Two procedures 

are used in the selection and culling process (B of fig. 1). 

The first is a generalized filtering program to remove 

anomalous data. During this prefiltering process, rare erroneous data values are placed in a separate file that prevents 

their influence during additional future examinations. The 

remaining data are passed to a culling program that has been 

designed to ( 1) statistically validate all data within selected 

areas, usually 250 m2 , (2) choose representative sounding 

values data within the selected areas, (3) and produce a 

reduced data set consisting of a maximum (deepest) depth, 

a minimum (shallowest) depth, and a depth value that is 

closest to the average for that particular selected area. 

Current processing retains between 2 and 25 percent of the 

original data during the combined selection and culling 

process, depending on water depth. The selected sounding 

values are transferred to a commercial software package, 

Radian Corporation's Contour Plotting System 1 (CPS-1). 

CPS-1 is used to derive the 250-m gridded coordinate 

values on a Universal Transverse Mercator (UTM) projection with the horizontal North American Datum of 1983 

(NAD 83) (D of fig. 1), and also employed to develop and 

plot the resulting contour data (G of fig. 1). 

If all the digital data along the coast were of the 

quality and quantity as the multibeam data and used highly 
,.. ,.. ,. --- ~ - -,. ,. ,. ~ 

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Figure 1. Multibeam processing flow. 

A 

B 

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F 

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UlliC'I' I CU1L DATA 

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Bridging the Gap-Creating Nearshore Bathymetric Maps from Multibeam Swath Sonar Systems and Conventional Hydrographic Data 119 
OFF SHORE COLU!CilON SYS'll!MS 

RANGE: 

ISOTO 

10,000 

MI!TERS 

MULTIBBAM 

IN SHORE DATA COLU!CilON SYSTI!MS 

RANGE: !FOOT 

150 FA1110MS ~ 

RANGE: 

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4000 FATHOMS 

RANGE: NEAR SHORE 1 LEAD WEIGHT 

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20 TO 60 DEGRI!ES 

FREQUENCY: 

I KHZ TO 21 KHZ 

U!ADUNE 

CALIBRATED 

ROFF/ CABI.l! 

RESENT 

1984 MULTIBEAM DATA COLU!CilON BI!GINS 

RESENT 

1980 DUAL BEAM SYSTEMS DEVELOPED 

1970 NARROW BEAM SYS'l1!MS 

!96S SURVEYS BI!G1N DIGITAL DATA COLU!CTION 

1940 MID-RANGE 808 FA1110MI!l'ER 

1939 Atll'OMATIC RECORDING PATHOMETER 

HUOHEs VI!SIJ!KARI 

19ll HIGH-PREaSION DORSEY Ill PA1HOMETER 

1925 312 PA1HOMETER DEVELOPED 

1920 ECHO SOUNDING DEVICB INTRODUCBD 

1837 FIRST HYDROGRAPHIC SURVEY 

Figure 2. Depth sounding technology and evolution. 

accurate navigation, bathymetric map composition would 

be greatly simplified. However, due to some of the nuances 

of inshore information, the resulting inshore bathymetric 

maps can be a bit more involved. 

HYDROGRAPHIC COLLECTION AND SYSTEM 

HISTORY 

Through an Act of Congress, hydrographic surveys 

have been used to chart the nearshore U.S. coastal waters, 

since 1807. These surveys have normally investigated 

particular features or navigational channels using sitespecific collection methods. Reconnaissance surveys also 

have been conducted to better approximate regions previously little understood and are sometimes used in advance 

of more detailed surveying. 

Technologies and methods of data collection have 

evolved over the years (fig. 2). Initial surveys were collected nearshore with leadline systems deployed vertically 

overboard to derive depths, which provided relatively good 

quality sounding values. As leadline technology matured, 

confidence increased in conducting offshore investigations. 

Yet, problems persisted in these deep-water areas, such as 

difficulty in obtaining nonvertical depth samples due to 

120 Proceedings, 1991 EEZ Symposium on Mapping and Research 

vessel movement; leadline migration because of unseen 

subcurrents; misreading depth values on the leadline; calling out and recording incorrect depth values aboard the 

vessel (in early surveys, values were actually called out by 

a leadsman and transcribed by a recorder). Because of these 

and other difficulties, there was a need for improved less 

time-consuming systems to gather offshore information. 

Starting in the early 1920's the first echo-sounding 

device, the sonic depth finder, was introduced to sample the 

ocean floor. In this system, depth values were determined 

by having an operator send a signal at a predetermined time 

and listening on headphones for the returning echo. 

The operator would then examine a variable-control 

mechanism to judge the depth. Much skill was required to 

determine results, but it was a marked advance in depth 

determination. 

In 1925, the first fathometer, known as the "312 

fathometer," was developed by the Submarine Signal Company of Boston, Mass. This system allowed an operator to 

determine depth values by correlating the echo heard in his 

headset while noting the reading on a continuous-rotating 

flashing white-light circular depth scale. This system was 

more accurate and, unlike the previous system, could be 

operated while the vessel was underway. 

The first precision instrument deemed accurate 

enough for hydrographic work was the Dorsey fathometer 

#1, developed in 1933 and deployed on the Lydonia in 

1934. This was truly a revolutionary system for its time as 

it incorporated the transmitter and receiver into one 

seawater-tolerant hull mounted unit called a transceiver, 

used supersonic operating frequency of 17 kHz, incorporated a mechanism for vibration dampening, had an operating range of from 3 to 900 ft, and had the ability to record 

depths automatically, which was a breakthrough introduced 

in 1939 by Hughes Veslekari's graph-recording instrument. 

This was a 16-kHz system that employed a 30°-wide-beam 

angle with an operating range of from 42 to 6,000 ft. 

A workhorse for shallow to intermediate surveying 

was the 808 fathometer. Introduced in 1940, permanently 

attached and portable variations of the device were used in 

offshore and nearshore work. The 808 would be the primary 

echo sounding mechanism in these water depths for the next 

25 yr. 

The mid-1960's saw the first revolution in digital 

collection of hydrographic data. This was a high-water 

mark that would result in computerized data acquisition for 

subsequent systems. During this period, several systems 

were deployed with most of the instruments in the lowfrequency and relatively wide-beamwidth (45°-60°) category. These systems were able to sample larger ocean-floor 

areas but did not always provide the best identification of 

some small-scale features. 

Narrow-beam reflector systems having beamwidths 

on the order of 6°-8°, coupled with higher frequencies, 

were designed in the mid-1970's to define more sharply the 
bottom's character. These systems were able to achieve 

better feature fidelity in areas of sloping and rough terrain. 

However, because of the narrow sampling nature of the 

instrument, this compromised the amount of area covered. 

To address the limitations and innovations gained 

from previous single-beam experience, dual frequency systems were employed in the 1980's. These systems, composed of a narrow high-frequency beam for precise depth 

measurements, and a wider low-frequency beam to sample 

the surrounding area, were employed to improve the confidence in depths resolved in shallow waters. These modem 

systems are now collecting the highest quality data for 

inshore surveys. 

CONSIDERATIONS 

In addition to the properties of the echo sounding 

devices, other elements are also critical in obtaining correct 

depth determinations. There are many factors in the water 

column that contribute to depth resolution, such as salinity, 

temperature, and pressure of the water; bubbles entrained 

through natural events or vessel movement; organic materials and suspended sediments; and vessel attitude and 

associated turbulence. 

The ocean floor's characteristics, such as substrate 

composition, orientation, and sea-floor roughness, all contribute to resolving vertical depth values. Perhaps the 

greatest factor in depth determination is the association of 

geographical positions to depth values. Latitude and longitude coordinates, or geographical positions, are attained 

through knowledge of fixed standard locations from which 

navigational processes can derive new positions. Navigation, which comes from the Latin derivative navigare, 

means "to direct ship." This ship direction takes the form of 

making a determination of the present location, recording 

its location, planning the course to the next position, 

attempting to regulate or control the vessel to the ensuing 

position, and again making a determination of the new 

location. 

Navigational techniques, like the methods used to 

calculate depth values, have also progressed over time. The 

initial historic nearshore surveys used visual means and 

sextants to resolve hydrographic positions. These early 

surveys' positions were derived from fixed, known land 

features that could be used as standards. Offshore positions 

were collected by using dead-reckoning skills that required 

sailing from original known positions and making estimates 

along the course. 

In the late 1920's, a method of navigation control 

beyond visibility of shore signals was developed. It was 

called Radio Acoustic Ranging (RAR). In RAR, a charge of 

TNT was detonated close to the vessel conducting the 

survey. The explosion caused acoustic waves to be radiated 

through the water. Hydrophone listening devices were 

placed at known locations near shore radio stations. Once 

the detonation was received at the shore stations, the time 

was recorded and then transmitted by the radio shore station 

to the collection vessel at sea. Thus, through a sequence of 

timing events of sound propagation through water, it was 

then possible to provide more accurate positions for vessels 

beyond the sight of land (Adams, 1942; Jeffers, 1960). 

At the end of World War II, a special type of radar 

system call Shoran was developed to improve navigational 

accuracies. With this system, vessel position was obtained 

by precisely measuring the elapsed time between a transmitted pulse and a return signal from two fixed shore 

stations. 

Improved long- and medium-range hyperbolic navigation systems were developed in the 1950's and 60's. The 

offshore systems included Hi-Fix, Sea-Fix, Raydist, loran 

and others. These systems measured phase shifts of two 

continuous-wave signals to determine position. This was 

accomplished by emanating signals from a vessel conducting the survey and two or more shore stations radiating the 

same signal. These systems also had the capability of 

operating in a range-range mode, where the distance could 

be determined from radio signals emanating from two or 

more precisely positioned shore stations. 

The newest satellite navigation systems, such as the 

differential mode of the Global Positioning System (GPS) 

have a much higher probability of accuracy and repeatability for position locations. 

Position approximations are generally made because 

of the relative uncertainty of the original position, because 

equipment is incapable of attaining sufficient precision, and 

because of incorrect instrument readings, random error 

sources from noise sources, and errors from systematic 

system biases. Most mislocated positions are usually a 

result of one or more of these errors. 

... navigation is not an exact science. A number of 

approximations that would be unacceptable in careful 

scientific work are used by the navigator, because 

greater accuracy may not be consistent with the 

requirements or time available, or because there is no 

alternative. (Bowditch, 1975.) 

COMBINING MULTIBEAM AND 

HYDROGRAPHIC DATA 

When completing inshore bathymetric map areas, the 

current goal is to produce sufficient coverage to create a 

uniform modeled (gridded) surface while preserving as 

much integrity as possible from individual surveys. 

Although multibeam systems are used to attain patterns of 

consistent coverage below the 150-m depth curve, shoaler 

areas must be augmented with hydrographic data. 

Thus far, the primary purposes of hydrographic 

survey data have been to support nautical charting activities 

such as deriving contour lines or providing spot soundings 

Bridging the Gap-Creating Nearshore Bathymetric Maps from Multibeam Swath Sonar Systems and Conventional Hydrographic Data 121 
Figure 3. Suggested line spacing (dashed lines) for area to 

be surveyed. 

as needed on the given manuscript. Rather than a systematic 

sweeping of the ocean floor, which has been technologically impossible until recently, data have been primarily 

collected to check for the depths that would be considered 

hazards to navigation (fig. 3). Thus, shallow areas have 

received more dense (closer line spacing) and more frequent 

(on periodic basis) coverage. Substantial efforts to review, 

select, and apply these values on the nautical charts have 

been, for the most part, through manual rather than automated methods. 

To date, approximately 10,000 surveys have been 

conducted by the National Ocean Service (NOS) in coastal 

waters (fig. 4). Approximately 10 percent of the surveys 

have been collected and processed digitally, from roughly 

1965 to the present; another 30 percent of the surveys have 

been converted from analog to digital form, covering the 

period from 1930 to 1965; and the vast majority of surveys 

prior to 1930, some 60 percent, are in a nondigital manu122 Proceedings, 1991 EEZ Symposium on Mapping and Research 

1992 

10 °/o DIGITAL 

1965 

30 °/o DIGITIZED 

1930 

60 o/o NON DIGITAL 

......... ~-------......... ~ 1837 

Figure 4. National Ocean Service hydrographic data10,000 surveys. 

script form. Some of the rna jor coastal areas of the 

continental U.S. , such as the areas illustrated in figure 5, 

have not been surveyed since the late 1920's. The surveys, 

once collected, act as historical records reflecting the 

current technology and processing for that particular era. 

When including hydrographic data, the preparations 

are somewhat like the multibeam methodologies with the 

following exceptions: 

(1) If data required in a map area are not in a digital form, 

decisions must be made in order to incorporate the 

information. Presently, two alternatives can be exercised. First, the original manuscripts can be retrieved 

from the archives, and a digitization process can be 

undertaken. This can often be a long and laborious 

process that requires a great deal of quality control to 

ensure the digital representation creates an authentic 

reproduction. Second, an experienced cartographer can 

review the information, manually draw sufficient contour levels that satisfy the orientation of the survey, and 

transpose the contours through a digitization or scanning process. In addition, software exists that can 

convert the contoured lines into a gridded model. 

However, depending on the data input and personal 

interpretation, results can vary. As a result, the first 

method is preferable not only to preserve the data for 

perpetuity but also to allow future interpretations and 

manipulations. 

(2) Digital data must be converted to a common form in 

terms of depth units and reference locations for alignment with multibeam data. Original depth values may 

have been collected in fathoms, ft, quarter-ft, or several 

other units of measurement and must be converted to 

meters. One must be aware that, due to improving 

technologies, the precision of measurement has generally increased over time. For instance, a newer system 

(fig. 6) may have the ability to discern finer units of 

resolution that in tum may yield slightly different 

results. In addition, if not already adjusted, each 
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--

PRE-1940'S 

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Figure 5. Survey distribution-San Francisco to Cape Flattery. 

Bridging the Gap-Creating Nearshore Bathymetric Maps from Multibeam Swath Sonar Systems and Conventional Hydrographic Data 123 
+ 1 METER 

UNITS 

COLLECTED 

IN 

WHOLE O 

METERS 

-1 METER 

NEW 

+ 1.8288036 METERS 

- 1.8288036 METERS 

Figure 6. System precision. 

1 FATHOM 

UNITS 

COLLECTED 

IN 

WHOLE 

FATHOMS 

-1 FATHOM 

OLD 

position must be converted to a common set of coordinates on the North American Datum of 1983 (NAD 83) 

for proper reference. 

(3) Data must be examined for density, orientation, and 

valid values. Data density can vary quite widely 

between historic hydrographic and multibeam data. In 

figure 7, the upper left portion of the map contains the 

outer edges of a hydrographic reconnaissance survey, 

while the center of the map represents a portion of a 

multi beam survey with only selected soundings. Thus, 

the data examination is accomplished by creating depthposition plots for each separate survey, selecting 

parameters for grid and contour generation based on 

coverage and orientation, removing definite erroneous 

data points, and revisiting the entire process once 

acceptable data have been obtained. 

( 4) Survey overlap and influence must be determined to 

establish data coverage and resolve conflicts in all 

surveys in the region. The decision process can be 

further complicated with multiple overlapping irregular 

survey junctions (fig. 8). Additional data selection is 

generally predicated on a progression of the most 

current and most dense hydrographic data ranging down 

to the most historic and most sparse. In a theoretical 

representation in figure 9, a section of multi beam data 

(lower left) is directly merged with a historical hydrographic data (upper right). The result is a compromised 

area that will most likely yield undesirable results when 

contoured. The solution for this example is to remove 

the intruding interior lines of data along with most of 

the historic data at the boundary to produce a reasonable 

solution. Although data elimination is an acceptable 

conclusion for most multibeam-to-hydrographic data 

interfaces, other hydrographic-to-hydrographic data 

124 Proceedings, 1991 EEZ Symposium on Mapping and Research 

+ + + 

Figure 7. Data density: Top, Conventional data; Middle, 

Contour data; Bottom, Multibeam data. 

areas may require further attention. In figure 10, two 

relatively sparse surveys are required for inclusion. 

Investigations and examinations have shown each data 

set to be consistent, significant, and necessary to derive 

an optimal depiction. As a result, the intruding data 

cannot be automatically eliminated, nor can the boundary data be reduced. 

(5) Surveys are gridded on an individual basis to retain 

feature integrity and reduce potential bias from adjacent 

data. Surveys also can be grouped together and processed if they have used the same type of instrumentation, navigation, and line spacing and have good 

agreement among them as the net result will be the 

same. 

(6) Once all grids have been resolved for the individual 

surveys and the junction areas, they are then mosaicked 

to form a complete surface model. Under normal 

conditions, multibeam data are always given the highest 

precedence due to their increased density, higher 
\ 

\ 

\ 

\ ~~' / 

\ y_/ 

"~ 

800092 

800093 

Figure 8. National Ocean Service survey index. 

~~~~ LINE INTRUSION 

HISTORIC HYDROGRAPHIC DATA 

3 

~ OVERLAP AREA 

~ 

3 

Figure 9. Possible multibeam-to-historic-hydrographic 

data interface. 

...... , 

', I I 

'-.....l I 8oo121 1 ~ 800039 

r--t---

1 I 

I I 

I I 

I I 

I 

D Intruding depth 

sounding values 

Figure 10. Possible hydrographic-to-hydrographic interface. 

Bridging the Gap-Creating Nearshore Bathymetric Maps from Multibeam Swath Sonar Systems and Conventional Hydrographic Data 125 
quality, and contemporary nature. This modeled surface is 

used to create the final map representation. 

CONCLUSION 

Throughout the history of the NOS, hydrographic 

surveys have evolved and improved due to advances in 

echo-sounding technologies, better navigation systems, 

incorporation of progressive technologies, and applications 

of advanced methods to process the information. This 

evolution has led to better support of the traditional mission 

of discovering and reporting hazards to navigation for 

nautical charting activities. Another direct result of the 

progression in surveys is the development of higher quality 

data products. 

Most hydrographic surveys were not specifically 

designed for computer operations, particularly from the 

time period prior to 1965, yet trends indicate that computerassisted methods will predominate in the future. As a result, 

one of the biggest obstacles in creating nearshore, 

computer-generated bathymetric maps and associated digital products may be the conversion of hydrographic data to 

a digital form that can be readily incorporated with the 

offshore multibeam digital data. 

For inshore areas the hydrographic challenges are to 

provide adequate digital data coverage, to attempt to retain 

individual survey characteristics and integrity, to resolve 

survey differences and eliminate spurious data, and to 

provide gradual progression between differing survey collection techniques and technologies. The desired result is to 

produce an aesthetically pleasing bathymetric product that 

can be used by a wide range of scientists, oceanographers, 

engineers, environmental planners, educators, and the general public in a printed cost-effective paper map form and 

computer-ready digital data set. 

126 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Currently, inshore hydrographic data are fit to the 

same 250-m grid model that has been used in the offshore 

regions. Although this methodology may be satisfactory for 

some applications by providing a continuous homogenous 

surface from the shallow to deep waters, it should be noted 

that small microtopographic features may be attenuated 

during the selection, gridding, and contouring processes. 

Through planning, examination, review, and consolidation, it is possible to produce nearshore bathymetric 

maps by blending both offshore multibeam data with 

inshore hydrographic data. However, the precision and 

accuracy of the combined bathymetric map are a direct 

result of the quality of the individual surveys from which it 

is compiled. 

SELECTED REFERENCES 

Adams, K.T., 1942, Hydrographic manual: U.S. Coast and 

Geodetic Survey, U.S. Government Printing Office, Washington, D.C., Special Publication Number 143. 

Bowditch, N. , 197 5, American Practical Navigator: Defense 

Mapping Agency Hydrographic Center, v. II, no. 9, p. 429. 

Jeffers, K.B., 1960, Hydrographic manual: Coast and Geodetic 

Survey, U.S. Government Printing Office, Washington, 

D.C., Publication no. 20-2. 

Matula, S.P., 1986, Using Exclusive Economic Zone digital 

swath data to select effective bathymetry, in Oceans '86 

Conference, Washington, D.C., 1986, Proceedings: v. 1, p. 

136-140. 

National Research Council, Commission on Engineering and 

Technical Systems, Marine Board, 1991, Interim Report of 

the Committee on Exclusive Economic Zone Information 

Needs-Seabed information needs of offshore industries: 

Washington, D.C., National Academy Press, 47 p. 
Processing EEZ Data in a Marine Geographic Information 

System 

Gail Lang ran and Donna J. Kall 

lntergraph Corporation 

Hydrographic and bathymetric data users are natural 

beneficiaries of a geographic information system (GIS). A 

GIS permits data of different type, format, content, resolution, and source to be combined into a whole that is greater 

than the sum of its parts. A GIS also can automate rote 

processing that normally would inflict boredom or eyestrain 

on a human. Analysis within a GIS can reveal subtleties in 

a data set that may go unnoticed with visual processing 

alone. 

Intergraph has developed a variety of commercial 

tools, including a marine GIS, for hydrographic and bathymetric data analysis. The proving grounds for these tools 

have been a series of U.S. Government programs designed 

to automate portions of nautical charting within the National 

Ocean Service and the Defense Mapping Agency. Figure 1 

provides an overview of Intergraph's hydrographic developments and the functional areas they span. 

Mariner, Intergraph's marine GIS, is of particular 

interest to users of data in the Exclusive Economic Zone 

(EEZ). Mariner provides the following capabilities: 

• Integration of raster and vector data from various 

sources; 

• Rule-based filtering of soundings to create a small 

representative dataset from a large one; 

• Statistical analysis of sounding data; 

• Detection of anomalies in sounding data; and 

• Data visualization utilities. 

The next sections describe each of these capabilities 

in tum and suggest a workflow for their use in analyzing 

data from the EEZ. 

DATA INTEGRATION 

Because undersea data are sensed but seldom seen, 

ground truthing is usually impossible. Thus, corroborating 

information assumes a greater role in undersea data analysis 

than in situations where the data gathered can be checked in 

more traditional ways. The goal is to use information from 

various sources to ensure that all evidence supports the 

assumptions derived analytically. 

Table 1 lists data sources that are useful in exploring 

the EEZ. The most obvious sources are multibeam surveys 

to describe bathymetry, and sidescan sonar for information 

on landforms and geology. Less obvious data sources are 

multispectral imagery (for example, SPOT or Landsat) that 

provides an overview of surface landforms and shallow 

water features; thermal imagery to interpret currents; radar 

( Hydrographic programs at lntergraph J ~----~-------r·--------T-----~--~·----~.~ 8 !S :=!::.::===u=:=~uti=Natlo::!ca=l na=C~=~=rtl=ng=n Syste=Servl==:!::::==:::!:~c:~~~) U.S. Department of Defense future ! : 

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I I 

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process process apply, disseminate, genereta genereta generate support 

unadjusted adjusted and track Incremental dlgHal finished bathymetric electronic 

hydro hydro updstes to Intelligent products charts maps charts 

surveys surveys databasa 

Figure 1. Overview of lntergraph's hydrographic development efforts. The captions at the bottom outline the 

spectrum of functions needed to process hydrographic 

data for nautical purposes. The labeled bars indicate 

which of these functions is performed within the various 

development efforts. 

Table 1. Corroborating data sources for EEZ exploration 

Data Sources Format Content 

Multibeam survey x,y, z Bathymetry. 

Sidescan sonar Raster Subsurface landforms, 

geology. 

Multispectral Raster Subsurface and near-surface. 

Landforms, geology. 

Thermal Raster Currents, mesoscale features. 

Radar altimetry X, y, Z Surface bulges. 

Thematic data Grid Magnetic, acoustic, and so 

forth. 

Nautical charts Raster/ Surface features, summary 

vector. of known data. 

Survey notes Vectors Tracklines of survey data. 

Processing EEZ Data in a Marine Geographic Information System 127 
altimetry to measure surface bulges that may reflect subsea 

landforms; nautical charts that describe surface features and 

the results of existing surveys; thematic data (for example, 

magnetic, acoustic, geologic, sedimentary, and so forth) 

that may explain anomalies in data values; and diagrams of 

surveys or survey notes. Each data type offers unique 

knowledge and must be treated slightly differently. 

A GIS provides a unified software module for working with multiple data types. At a minimum, data can be 

viewed and mapped in concert so they are presented more 

conveniently to a human analyst. But GIS algorithms also 

exist for automated analysis of multiple data types. For 

example, using thematic gridded data and by creating a 

gridded bottom model from soundings, the system can 

respond to such queries as "find all locations with sandy 

bottom and slope less than 10 percent" or "find all rocky 

areas whose aspect faces east (which is toward a faultline)." 

As new and successful modes of analysis are discovered, 

many can be automated and incorporated within an integrated information system. 

RULE-BASED SOUNDING SELECTION 

Multibeam survey data are voluminous because surveys are planned to detect all significant bathymetric 

variation. Dense data collection is critical so no gaps exist; 

however, once the surface is fully described, the description 

can be abbreviated by filtering soundings that represent 

redundant information. 

Mariner provides data filtering functions that permit a 

user to model a surface by selecting a subset of the 

soundings collected in a survey. The filtering functions 

permit a user to express the characteristics of the desired 

model by defining rules for sounding selection. The user 

can direct the algorithms to select soundings differently in 

the nearshore area than in deeper water; to base sounding 

density on vertical and horizontal differences between 

neighbors; to choose only local highs, or both "highs" and 

"deeps;" and, to associate different "rule tables" to different 

areas of the data set. 

An overview of the commands that govern Mariner 

sounding selection rules follows. 

• Define vertical tolerances between neighboring soundings by difference upward, difference downward, and 

absolute or percent change. 

• Define horizontal tolerance in terms of minimum and 

maximum spacing between soundings. 

• Define depth ranges in which different sets of horizontal 

or vertical tolerances will be used. 

• Define depth contour values. 

• Select or do not select local lows. 

Rule-based filtering of soundings allows different 

users to model the bottom for different purposes. For 

example, to model the bottom for hydrographic purposes, 

128 Proceedings, 1991 EEZ Symposium on Mapping and Research 

the user could direct the algorithm to select shoaler soundings for a bias toward safe navigation. Smaller variations in 

the bottom could be mapped nearshore by setting smaller 

vertical tolerances in shallower depths. A denser sounding 

selection could be performed in the . nearshore area by 

setting a smaller horizontal tolerance in shallower depths. 

Conversely, to model the bottom for bathymetric purposes, 

the user could direct the algorithm to select both highs and 

deeps, set consistent vertical tolerances based on the 

amount of variation that is significant to the user, and set a 

consistent horizontal tolerance so soundings are selected 

consistently across the model. 

A key element of Mariner's filtering procedure is the 

use throughout of actual sounding data. No interpolation 

occurs, as it does when a surface is modeled by a grid. 

Rather, the soundings are joined into a bottom model via a 

triangulated irregular network (TIN). The TIN, which is 

comprised of triangles whose vertices have elevations, 

becomes a surface represented by triangular facets. The 

advantage of TIN modeling is that no interpolation (and 

subsequent degradation of data) occurs and that the original 

and the selected data sets can be compared by comparing 

the two surfaces described by the original and derived 

TIN's. 

STATISTICAL ANALYSIS OF SOUNDING DATA 

Mariner provides a variety of descriptive statistics to 

help in validating soundings from a given source. It is 

possible to compute the minimum, maximum, mean, and 

standard deviation of soundings in a specified source. 

Comparing these values for different surveys in the same 

area gives an indication of how well the different sources 

agree. Likewise, to compare a filtered model of the bottom 

to the original model, Mariner provides a summary of 

soundings considered, selected, number of local highs 

selected, number of local lows selected, those selected 

interactively by the analyst, and background or support 

soundings that fill in the model but do not necessarily 

provide significant new information. Mariner also will 

compute the root mean square error between the full and 

selected soundings data sets. 

DETECTION OF ANOMALIES 

Data anomalies, or spikes, are of interest for two 

reasons: they may be errors, or they may be areas with 

interesting geological formations. Mariner provides a timesaving means of analyst assistance in evaluating data 

anomalies. The user enters the horizontal and vertical 

difference that would be considered a spike, and the system 

locates all instances of such differences and presents them, 

one by one, to the user. The presentation of each spike 

includes cross-section views along the x and y axis of the 
spike. Based on the situation, the user can choose to have 

the sounding deleted, remain in the data set but not be 

selected for the filtered model, or otherwise. If the original 

parameters locate too many or too few spikes, they can be 

fine-tuned during processing. 

VISUALIZATION UTILITIES 

Many different graphic depictions of surfaces are 

possible in Mariner. Mariner can color-code soundings, 

triangle edges, contours, or areas by depth. Mariner also 

can construct a three-dimensional perspective view of the 

bottom by using these different colorations. When comparing two different bottom models in the same region, 

Mariner can color-code the differences between the models 

(where they overlap) for closer scrutiny by the analyst. 

USING MARINER IN EEZ DATA ANALYSIS 

Many users prefer to begin their analysis of multibeam sounding data with a walkthrough in three dimensions of the complete data set. Such a walkthrough can 

involve as many as 50 million soundings, densely spaced. 

Computer graphics technology permits the user to visualize 

the undersea terrain and decide what areas are of interest for 

in-depth analysis. 

A possible workflow for data analysis of this type 

would be to conduct a walkthrough of the complete data set 

and flag areas that would be exported for processing in 

Mariner. Intergraph has developed a "Spaceball" product 

that, when used with Intergraph' s "Model view," permits 

the user to steer him or herself through the model using 

pressure on the surface of a spherical mouse. By adding a 

utility (which does not currently exist) to flag an area, a 

postprocess could be performed to extract x, y, z data from 

the flagged area into a new data subset for input to Mariner. 

A variation on this workflow (in cases where an entire 

multibeam survey was to be filtered) would be to perform 

the walkthrough, then systematically segment the complete 

data set into units of a smaller size manageable by Mariner. 

CONCLUSIONS 

GIS technology can assist marine users by integrating 

data from various sources. It can also analyze bathymetric 

data with the use of corroborating information provided by 

other types of marine surveys. Mariner, lntergraph' s marine 

GIS, adds customized hydrographic and bathymetric data 

analysis capabilities to traditional land-based GIS functions. 

Mariner can be combined with Intergraph' s visualization 

products, Modelview and Spaceball, to create a production 

workflow that combines the intuitive power of walkthrough 

data viewing with the analytic power of a GIS. 

Processing EEZ Data in a Marine Geographic Information System 129 
Defense Mapping Agency's Defense Hydrographic Initiative and the DOD Bathymetric Digital Data Library and 

Hydrographic Source Assessment System 

james Patrick Moran 

Defense Mapping Agency 

Abstract 

The Defense Mapping Agency's Defense Hydrographic Initiative is a research and development program 

for the modernization of collection, evaluation, and processing of bathymetric data. The Department of Defense 

Bathymetric Digital Data Library concept is that of a 

centralized distributed library network amongst the 

Defense Mapping Agency, Navy, and the National Oceanic and Atmospheric Administration. The controlling 

mechanism for this library system is the Hydrographic 

Source Assessment System. The Hydrographic Source 

Assessment System will provide meta data and area of 

130 Proceedings, 1991 EEZ Symposium on Mapping and Research 

coverage about each bathymetric source and provide 

instructions to the library management system for processing and servicing. The Hydrographic Source Assessment System is expected to monitor collection activities 

and to perform active tasking functions in the future. The 

schedule plan of action and milestones is in concert with 

the Defense Mapping Agency's Digital Production System 

effectivity milestones. The ultimate goal from this development is the cooperative effort amongst library network 

nodes for a shoreline-to-shoreline bathymetric digital data 

library. 
COAP-A New Approach to Ocean Data Distribution 

William G. Schramm 

National Oceanic and Atmospheric Administration 

Abstract 

The National Oceanic and Atmospheric Administration Center for Ocean Analysis and Prediction (COAP) in 

Monterey California has implemented a new Relational 

Data Base Management System (RDBMS) for oceanographic data. The system, called NEONS, was developed 

by the Navy and is designed to manage images, gridded 

data, and observational data. In addition, COAP is implementing two new systems to provide access to the 

RDBMS. The first system, called NODDS, can be used with 

PC's and MAC's and uses telephone lines for communications. The second system is intended for use with more 

powerful computers and INTERNET. 

COAP-A New Approach to Ocean Data Distribution 131 
Geology and Hydrothermal Deposits at Escanaba Trough, 

Southern Gorda Ridge 

Randolph A. Koski, janet L. Morton, Stephanie L. Ross, and Robert A. Zierenberg 

U.S. Geological Survey 

INTRODUCTION 

Southern Gorda Ridge is a slow-spreading ocean 

ridge (2.4 cm/yr total opening rate) that is located 200-300 

km offshore of northern California and southern Oregon 

(fig. 1A). Escanaba Trough, the southernmost part of the 

Gorda Ridge spreading axis, is characterized by a 5- to 

15-km-wide, relatively flat valley floor at a water depth of 

3,300 m; flanking ridges rise 800-1,200 m above the valley 

floor. Turbidites and hemipelagic sediment filling the 

southern two-thirds of the trough are as thick as 700 m. 

Recent igneous activity in the trough is confined to discrete 

volcanic edifices where sills intrude the sediment layers; 

basalt flows are locally extruded at the sea floor. Steepsided sediment hills, about 1 km in diameter and 50-100m 

in height, probably formed by uplift due to intrusion of 

basaltic sills near the sediment-basement interface. Massive 

sulfide deposits with lateral and vertical dimensions measured in hundreds and tens of meters, respectively, formed 

on the flanks of these hills (Morton and others, 1987; 1990; 

Koski and others, 1988). 

SESCA AND NESCA SITES 

Two volcanic edifices have been studied in detail: the 

SESCA (Southern Escanaba) and NESCA (Northern Escanaba) sites (fig. lB; Zierenberg and others, in press; Morton 

and Fox, in press). The sea floor is topographically rougher 

at these sites than in the surrounding axial valley; the most 

notable features are several small ( < 1 km diameter), 

steep-sided hills (figs. 2, 3). Based on 3.5-kHz subbottom 

profiling and single-channel water gun reflection profiling, 

the undisturbed sedimentary fill appears to have a uniform 

seismic character and thin, highly reflective layers from 2 to 

10m apart (fig. 3). The layers probably correspond to sand 

or coarse silt beds. A seismically transparent zone at about 

85 to 130 m below the sea floor is observed on most of the 

profiles adjacent to the sediment hills (fig. 3). This interval 

is interpreted as a homogeneous, thick, sand-rich layer 

similar to those that occur in cores from Deep Sea Drilling 

132 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Project Site 35 southeast of SESCA (fig. lB). Near the 

sediment hills, there is an abrupt transition from the 

well-layered, relatively undisturbed sediment to faulted and 

tilted beds. The disrupted strata at the periphery of the 

North Hill at SESCA indicates that the hill is fault bounded 

(fig. 3). Strong reflectors subjacent to the North Hill may 

represent one or more sills. The hill itself, however, appears 

to be composed of uplifted sediment. 

HYDROTHERMAL DEPOSITS 

The mineral deposits in the Escanaba Trough have 

been sampled by dredge, gravity core, and submersible and 

include large pyrrhotite-rich mounds, polymetallic (Zn-FePb-Cu-As-Sb-Ag) sulfide structures, and barite chimneys 

and crusts (Koski and others, 1988; Koski and others, in 

press). Sulfate (barite + anhydrite) sinters are forming 

around active vents with maximum measured temperatures 

of about 220 oc. Compared to massive sulfide deposits 

formed at sediment-starved ocean ridges, sulfide samples 

from the Escanaba Trough are enriched in copper (to 20.6 

percent), arsenic (to 2.8 percent), lead (to 14 percent), 

silver (to 680 parts per million (ppm)), bismuth (to 820 ppm), 

antimony (to 8,700 ppm), and tin (to (1,500 ppm). Gold 

contents are as high as 10. 1 ppm in copper-rich mound 

samples. Pyrrhotite is the predominant mineral in massive 

sulfide samples, but isocubanite, chalcopyrite, sphalerite, 

marcasite, arsenopyrite, and galena are abundant in some 

samples. Minor phases include barite, lOllingite, stannite, 

boulangerite, jordanite, tetrahedrite, native bismuth, alabandite, and covellite. The abundant barite and enrichment 

of metals such as lead, arsenic, antimony, and bismuth in 

the sulfide deposits indicate significant interaction between 

hydrothermal fluids and the sediment. The widespread 

distribution and large size of hydrothermal deposits in 

Escanaba Trough are the result of long-lived, sedimenthosted hydrothermal convection cells driven by heat sources 

located at depth within the volcanic edifices. 
48" 

44° 

Explorer Ridge, 

Juan 

de 

Fuca 

Ridge 

Gorda Ridge 

40° 

136" 132" 

A 128° 124° 

Figure 1. A, Location of Escanaba Trough, southern Gorda 

Ridge, and other spreading axes in the northeast Pacific 

Ocean . The dotted line indicates the limit of the U.S. 

Exclusive Economic Zone. 8, Generalized map of Escanaba 

SEDIMENT ALTERATION 

Sediment samples recovered in gravity cores are 

characterized by magnesium metasomatism and the formation of smectite and chlorite (Zierenberg and Shanks, in 

press). The alteration of fine-grained sediment to nearly 

monomineralic aggregates of clinochlore (Fe/Fe+ Mg=21) 

was accompanied by an increase in magnesium from 4 to 25 

weight percent, the nearly complete removal of sodium, 

potassium, rubidium, calcium, and strontium, and a 

decrease of 8 180 in the bulk sediment. Oxygen isotope 

fractionation temperatures calculated for smectite ( 181-235 0

C) and chlorite (203-223 oq are consistent with measured 

temperatures of vent fluids (Zierenberg and Shanks, in 

press). The alteration of surficial sediment at temperatures 

near 200 °C has occurred during the mixing of upwelling 

hydrothermal fluid with seawater circulating at shallow 

depth. 

1111 

• 

(2] 

41°30' 

BASALT 

VOLCANIC 

EDIFICE 

SEDIMENT 

FILL 

• TERRACE 

t FAULT 

41°00' 

B 

Trough showing the location of the NESCA and SESCA 

study areas, the location of volcanic edifices, the approximate extent of sediment fill , and the location of Deep Sea 

Drilling Project Site 35. 

HILL FORMATION AND CIRCULATION 

MODEL 

The preferred model for the formation of sediment 

hills at SESCA and NESCA sites is uplift above laccoliths 

emplaced near the base of the sedimentary section (fig. 4). 

During emplacement, these basaltic intrusions inflate at the 

sediment-basement interface and uplift the overlying sedimentary section to form hills (Denlinger and Holmes, in 

press). Fault zones created by the uplift provide cross-stratal 

permeability and serve as major pathways for hydrothermal 

fluids. Thus, two main factors control the location of sulfide 

mineralization at the SESCA and NESCA sites (Morton and 

Fox, in press): (1) faults that formed as the hills were 

uplifted provide the primary conduits for ascending hydrothermal fluids and localized deposition of sulfide along the 

perimeter of the hills and (2) sand layers that allow 

horizontal migration of hydrothermal fluids away from the 

Geology and Hydrothermal Deposits at Escanaba Trough, Southern Gorda Ridge 133 
SESCA 12MI' 

1000 1000 10,000 12,000 ,.,000 tt,OOO 

Figure 2. SESCA area showing the uplifted sediment hills, regions of disturbed and undisturbed sediment, and the 

inferred extent of volcanic flows at or near the sea floor. 

fault zones, and thus movement results in subsurface sulfide 

deposition. 

IMPORTANCE OF STUDIES IN THE ESCANABA 

TROUGH 

The Escanaba Trough is a natural laboratory within 

the U.S. Exclusive Economic Zone for the investigation of 

active hydrothermal systems and their deposits in a 

sediment-covered rift environment. The deposits discovered 

in Escanaba Trough contain significant quantities of copper, 

zinc, silver, gold, and other metals and are among the 

134 Proceedings, 1991 EEZ Symposium on Mapping and Research 

largest yet observed on the ocean floor. Furthermore, 

deposits in the Escanaba Trough are formed in a lithological 

and chemical environment analogous to economically 

important sediment-hosted deposits on land. Additional 

studies at Escanaba Trough will benefit our understanding 

of the genesis and structural control of sediment-hosted 

sulfide deposits, the interaction of hydrothermal fluid and 

sediment, and the source rocks for ore metals. Future 

studies will be heavily dependent on additional mapping by 

use of midrange sidescan sonar systems, observations in 

the third dimension by use of high-resolution subbottom 

profiling, and sampling from drilling platforms and sub-
(/) 

0 

z 

0 

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w 

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~ 

w 

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w 

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Figure 3. Single-channel water gun profile 10 over the 

North Hill at SESCA. "T" marks an acoustically transparent 

zone about 85 to 130m below the sea floor. V.E., vertical 

exaggeration. 

mersibles. The U .S. Geological Survey plans to conduct 

sidescan and reflection profiling geophysical surveys in 

Escanaba Trough in 1992. 

REFERENCES CITED 

Denlinger, R.P., and Holmes, M.L. , in press, A thermal and 

mechanical model for sediment hills and associated sulfide 

deposits along the Escanaba Trough, in Morton, J.L., Zierenberg, R.A. , and Reiss, C. A., eds., Geologic, hydrothermal, 

and biologic studies at Escanaba Trough, Gorda Ridge, 

offshore northern California: U.S. Geological Survey Bulletin 2022 , chap. 4. 

Holmes, M.L. , and Zierenberg, R.A., 1990, Submersible observations in Escanaba Trough, southern Gorda Ridge , in 

McMurray, G.R. , ed., Gorda Ridge, a sea-floor spreading 

center in the United States' Exclusive Economic Zone: New 

York, Springer-Verlag, p. 93-115. 

Koski, R.A., Benninger, L.M., Zierenberg, R.A., and Jonasson, 

I.R., in press, Composition and growth history of hydrothermal deposits in Escanaba Trough, southern Gorda Ridge, in 

Morton, J.L., Zierenberg, R.A., and Reiss, C.A., eds., 

Geologic, hydrothermal, and biologic studies at Escanaba 

Trough, Gorda Ridge , offshore northern California: U.S. 

Geological Survey Bulletin 2022, chap. 16. 

Koski , R.A., Shanks, W.C. , III, Bohrson, W.A., and Oscarson, 

R.L., 1988, The composition of massive sulfide deposits 

from the sediment-covered floor of Escanaba Trough, Gorda 

CIRCULATION MODEL 

Figure 4. Schematic diagram summarizing the basic features controlling the uplift of sediment hills, flow of 

hydrothermal fluids, and formation of sulfide deposits on 

and below the sea floor. 

Ridge: Implications for depositional processes: Canadian 

Mineralogist, v. 26, p. 655-673. 

Morton, J.L. , and Fox, C.G. , in press, Structural setting and 

interaction of volcanism and sedimentation at Escanaba 

Trough: Geophysical results, in Morton, J.L., Zierenberg, 

R.A., and Reiss, C. A. , eds., Geologic , hydrothermal, and 

biologic studies at Escanaba Trough, Gorda Ridge, offshore 

northern California: U.S. Geological Survey Bulletin 2022, 

chap. 2. 

Morton, J.L., Holmes, M.L. , and Koski, R.A., 1987, Volcanism 

and massive sulfide formation at a sedimented spreading 

center, Escanaba Trough, Gorda Ridge, northeast Pacific 

Ocean: Geophysical Research Letters, v. 14, p. 769-772. 

Morton, J.L., Koski, R.A., Normark, W.R., and Ross, S.L., 

1990, Distribution and composition of massive sulfide deposits at Escanaba Trough, southern Gorda Ridge, in McMurray, 

G.R., ed., Gorda Ridge , a sea-floor spreading center in the 

United States' Exclusive Economic Zone: New York, 

Springer-Verlag, p. 77-92. 

Zierenberg, R.A., Morton, J.L., Koski, R.A. , Ross, S.L. , and 

Holmes, M.L., in press, Geologic setting of massive sulfide 

mineralization in the Escanaba Trough, in Morton, J .L., 

Zierenberg, R.A., and Reiss, C.A., eds., Geologic , hydrothermal, and biologic studies at Escanaba Trough, Gorda 

Ridge, offshore northern California: U.S. Geological Survey 

Bulletin 2022, chap. 10 . 

Zierenberg, R.A. , and Shanks, W.C., III, in press, Sediment 

alteration associated with massive sulfide formation in the 

Escanaba Trough, Gorda Ridge: The importance of sea water 

mixing and magnesium metasomatism, in Morton, J.L. , 

Zierenberg, R.A., and Reiss, C.A., eds., Geologic , hydrothermal, and biologic studies at Escanaba Trough, Gorda 

Ridge, offshore northern California: U.S. Geological Survey 

Bulletin 2022, chap. 14. 

Geology and Hydrothermal Deposits at Escanaba Trough, Southern Gorda Ridge 135 
West Coast GLORIA on CD-ROM 

Joseph M. Coddington 

U.S. Geological Survey 

The U.S. Geological Survey (USGS) began its 

sidescan-sonar survey of the Exclusive Economic Zone 

(EEZ) in the summer of 1984 off the coasts of Washington, 

Oregon, and California. In 100 days, the EEZ was mapped 

from the Canadian to the Mexican border, extending from 

the continental shelf edge (approximately 200 m water 

depth) to the seaward 200 nmi boundary. Results of this 

survey were published by the USGS (EEZ-SCAN 84 

Scientific Staff, 1986). 

This first EEZ atlas was distributed as a paper 

publication. Because the computer programs to digitally 

mosaic the Geologic LOng-Range Inclined Asdic 

(GLORIA) imagery were unavailable, it was necessary to 

use the manual cut and paste method to mosaic GLORIA 

image data. The paper medium, however, is not as flexible 

as the digital form of manipulating and displaying image 

data. Therefore, after the programs became available, it was 

decided that the West Coast GLORIA imagery would be 

digitally mosaicked and then distributed on Compact Disc 

Read Only Memory (CD-ROM). 

The projection chosen for the mosaicking process was 

Transverse Mercator. The data were digitally mosaicked 

into 2°X2° quadrangles. This procedure required taking 

individual straight-line segments of image data and removing the header information at the beginning of each scanline record. The data were stretched to ensure homogeneity 

with adjacent line segments and run through the transformation and geometric programs to locate the line segment's 

position and orient it within the image space (quadrangle). 

Each line segment was then digitally pasted together with 

other line segments into the quadrangle. Finally, because 

there was intentional overlap of data between line segments, 

the overlapping data of lesser quality were cut and discarded 

using a process called stenciling. This process was repeated 

multiple times for each quadrangle depending on the number of line segments lying within each quadrangle's coordinates. 

136 Proceedings, 1991 EEZ Symposium on Mapping and Research 

The corresponding bathymetry on the disc is comprised of data from multiple sources and displayed as 

contours at intervals of 100 m. Most of the contours were 

scanned from preexisting maps ranging in scale from 

1:250,000 to 1:1,000,000. 

Special display software has been included on 

CD-ROM to increase the speed of the compressed image 

presentation to the computer screen as well as to permit 

bathymetry and tracklines to be superimposed on images. 

Files containing all lines and samples for each quadrangle 

permit display of the data at full resolution. 

The GLORIA imagery included on this CD-ROM 

extends from 40° to 49° N. latitude, while the bathymetry 

extends from 30° to 49° N. latitude. There are plans for a 

future CD-ROM containing all quadrangles for the West 

Coast EEZ, as well as associated bathymetry and tracklines. 

EEZ GLORIA data for the U.S. East Coast and the 

Gulf of Mexico are also available on CD-ROM. For 

information on how to obtain a copy of these data, contact 

the author(s) of the CD-ROM desired. 

To request a copy of the CD-ROM for Washington, 

Oregon, and Northern California EEZ areas only, contact 

Joseph Coddington at the: 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

(415) 354-3055 (Commercial) 

or send a via Internet E-mail to joseph@pmgvax.wr.usgs. 

gov. 

REFERENCE CITED 

EEZ-SCAN 84 Scientific Staff, 1986, Atlas of the Exclusive 

Economic Zone Western Conterminous United States: U.S. 

Geological Survey Miscellaneous Investigation Series 

1-1792, 152 p. 
The Use of Geographical Information Systems (GIS) to 

Facilitate Ocean Site Designation for Disposal of Harbor 

Dredged Materials 

Robert K. Hall and Allan Y. Ota 

U.S. Environmental Protection Agency Region IX 

Norman M. Maher and Gregory Gabel 

U.S. Geological Survey 

Abstract 

The U.S. Environmental Protection Agency is responsible for ocean disposal site designation under the provisions of Section 102 of the Marine Protection, Research, 

and Sanctuaries Act of 1972. Environmental Protection 

Agency Region IX, together with other Federal and State 

agencies, is studying the continental margin offshore of 

San Francisco, Calif., to designate an ocean dredged 

material-disposal site. The types of data collected range 

from sediment samples to marine bird and mammal 

counts. These data are acquired to better understand the 

region for ocean-disposal site designation. Geographic 

information systems technology is capable of integrating 

these diverse data types such as geological, geophysical, 

biological, and oceanographic data into relational, thematic coverages. Development of these thematic maps 

into two-dimensional and three-dimensional images 

enhances visual and spatial analysis and allows assessment 

of potential environmental impacts at candidate oceandisposal sites. 

INTRODUCTION 

The Environmental Protection Agency (EPA) Region 

IX's involvement in ocean-disposal site designation is part 

of a broad dredged-material management initiative entitled 

the Long Term Management Strategy (LTMS) for San 

Francisco Bay. The L TMS is a cooperative effort of the 

U.S. Army Corps of Engineers (Corps) and other Federal, 

State, and local agencies to develop an environmentally 

sound 50-yr plan for dredging and dredged-material disposal in the San Francisco Bay region. One of the L TMS 

objectives is to determine disposal alternatives for dredged 

material. Included in this study are reuse and nonaquatic 

alternatives (habitat and marshland creation, levee rehabilitation, and beach nourishment) in-bay studies, and ocean 

disposal sites. 

Maintenance dredging of San Francisco Bay is necessary to maintain navigational channels and to assure 

access to boat docking and repair facilities. The environmental impact of dredging and disposal operations within 

the bay is a major concern. Resource and regulatory 

agencies are concerned that existing disposal sites within 

the bay are approaching capacity. An alternative to in-bay 

disposal is to dispose of harbor-dredged material offshore. 

Currently, there is only one existing ocean-disposal site for 

dredged material adjacent to the San Francisco Bay region. 

The location of this site, the San Francisco Channel Bar 

Site, is outside the entrance to San Francisco Bay (fig. 1). 

The Channel Bar site is for sandy material dredged from the 

Golden Gate approach channel to San Francisco Bay. 

Approximately 4 to 5 million cubic yards of sediment 

are dredged from the bay each year. In 1990, the Corps 

identified projects for channel improvements involving the 

dredging of more than 19 million cubic yards (Wakeman 

and Chase, 1990). New projects, including proposals for 

deepening port channels within the bay, would add significantly to this total. There is a need for a suitable ocean site 

to provide an option to upland or in-bay disposal. 

EPA OCEAN STUDIES 

EPA Region IX is the lead agency for ocean-disposal 

site designation off San Francisco. Site selection is based 

upon adequate scientific studies, environmental analysis, 

and monitoring strategies to reduce adverse impacts. Selection of five EPA study areas (fig. 2) was made after 

discussions with Federal and State agencies and local 

interest groups. The locations of the study areas are south 

and west of the Gulf of the Farallones National Marine 

The Use of Geographical Information Systems (GIS) to Facilitate Ocean Site Designation for Disposal of Harbor Dredged Materials 137 
IS 

fp::::l::::::::::::::::::i30'iz::::::::::::::::::::ztm122.1S Gulf of lhe Farallones National 

Mmne Sanctuary boundary 

Cordell Bank National Marine 

Sanctuary Boundary 

EPA study uea 

- 100- Balhymcuy in mc:lc:!s 

Figure 1. San Francisco Bay region with offshore bathymetry and Site 1. 

Sanctuary (GOFNMS). Study Area 1, the Channel Bar Site, 

is not part of the present field studies plan. Study Area 2 is 

on the continental shelf just south of the GOFNMS in water 

depths of 60-120 m. Study Area 3 is on the continental 

slope just north of Pioneer Canyon in water depths of 

550-1,900 m. Study Area 4 is just south of Pioneer Canyon 

in water depths of 1,000-1,900 m. Study Area 5 is west of 

the GOFNMS in water depths of 1,900- 3,100 m. 

In July and August, 1990, the U.S. Geological 

Survey (USGS), with funding provided by the Corps and 

EPA, conducted a preliminary survey of the continental 

slope within the EPA study areas off San Francisco (Karl 

138 Proceedings, 1991 EEZ Symposium on Mapping and Research 

and others, 1990a). The objective of the survey was to 

characterize the sea-floor morphology, describe sediment 

characteristics, and identify areas of instability. Previous 

studies in the area by the USGS included a sidescan sonar 

survey in 1984 using the wide-swath Geological LOng 

Range Inclined Asdic (GLORIA) system in 1984 (EEZSCAN 84 Scientific Staff, 1986). In 1989, the USGS 

conducted a geological, geophysical, and physical oceanographic study for the National Oceanic and Atmospheric 

Administration Sanctuary Office within the GOFNMS 

(Chin and others, 1989; Noble and Gelfenbaum, 1990; 

Maher and others, 1991). 
15' 

15' 

Gulf of the Faralloncs National 

Marine SanCilluy boun<Wy 

Cordell Bank National Marine 

SaoCilluy Boundary 

EPA sllldy area 

- 100- Bathymeay in melciS 

122"15' 

Figure 2. Gulf of the Farallones and Cordell Bank National Marine Sanctuaries and EPA study areas. 

Before the 1990 preliminary survey, there was very 

little geological, geophysical, and physical oceanographic 

information for the continental slope off San Francisco. 

Most of the benthic biological data in the study areas were 

for the continental shelf. Also, fisheries and marine birds 

and mammals information had large data gaps for ocean 

areas south and west of the Farallon Islands. The 1990 

preliminary survey was the first of many ocean studies to 

improve the data base for the region of the continental slope 

west and south of the GOFNMS. 

GEOGRAPHICAL INFORMATION SYSTEMS 

(GIS) AND IMAGE PROCESSING 

By policy, EPA follows National Environmental 

Policy Act requirements and prepares an Environmental 

Impact Statement (EIS) for all ocean-disposal site designations (EPA Region IX, 1991). Among the items required to 

prepare an EIS are maps for computer models, spatial 

analyses, and public presentations. To put GIS to work on 

the site designation EIS, the data collected during the 

The Use of Geographical Information Systems (GIS) to Facilitate Ocean Site Designation for Disposal of Harbor Dredged Materials 139 
Boundaries 

Data Types, Locations, and Analysis Base Map Remotely Sensed 1 mages • Zone of Siting Feasib11ity 

• EPA Study Areas • Coastline • Side scan Sonar • Currents & Hydrographic Properties 

• National Marine Sanctuary • Sediment 

• Vessel Traffic Lanes • Bathymetry • Satellite Images • Geophysical 

• Radioactive Waste Dumping ! ! • Benthic lnfauna 

• Chemical Munitions Dumping • Fisheries & Ep1fauna 

• Submarine Operating Areas • Marine Birds & Mammals 

Geographic Information System (GIS) I 

I 

t t t 

2-D1mens1onal & 3-D1mens1onal Modeling Dredged Material 

Coverages/Overlays Spatial Analysis to Identify Areas Footprint & Plume Dispersion With High Potential For Disposal 

• Maps for Public Presentation Site Designation 

& Environmental Impact 

+ Statement I 

~ Environmental Impact Statement (EIS) 1 

t 

I Site Designation Preferred Alternative I 

t 

I Site Designation I 

t 

Site Management & Monitoring Plan Implementation I 

Figure 3. Data inputs and GIS analyses utilized in the EIS process for site designation. 

1990 surveys were first imported into a mainframe computer. Next, creation of thematic overlays and shaded relief 

images (Chavez, 1984; Chavez, 1986; Hall and others, 

unpub. data) were completed for the study areas. These 

overlays and other two-dimensional and three-dimensional 

images allow researchers and decisionmakers to view the 

data types in various combinations and with different 

perspective views for modeling and spatial analysis. 

Figure 3 is a flow chart showing the different types of 

coverages being incorporated into a GIS data base. The 

objective of the GIS is to view different boundary layers and 

data types together with the base map and remotely sensed 

imagery. After the EIS has been completed and a disposal 

site is designated, GIS also can aid the site manager in 

monitoring the disposal site and enforcing disposal permits. 

Boundary and base-map information was imported to 

a GIS to generate thematic coverages and shaded-relief 

images. The EPA study areas were originally selected by 

using several criteria (fig. 4). For example, the location and 

shape of each study area was designed not to conflict with 

other ocean areas already in use. Figure 4 shows the 

boundaries and location of the Gulf of the Farallones 

140 Proceedings, 1991 EEZ Symposium on Mapping and Research 

National Marine Sanctuary and Cordell Bank Sanctuary, 

vessel traffic lanes, submarine operating areas, and U.S. 

Navy chemical munitions and explosive disposal areas, 

with respect to the bathymetric shaded-relief base map. 

Study Areas 2, 3, and 4 are outside or between areas of 

active or historical use. Study Area 5 incorporates a former 

Navy chemical munitions disposal site and a large portion 

of a submarine operating area. 

Data from recent field studies and existing data bases 

are being used as inputs for GIS analysis. Sidescan sonar 

data were acquired to describe the sea-floor morphology 

(Karl and others, 1990b; Danforth and others, unpub. data). 

Sonar data and satellite images are incorporated into GIS as 

base maps for thematic overlays. Gravity cores were taken 

to describe sediment characteristics in the study region (fig. 

5), including grain size, sediment chemistry, and geotechnical properties (Karl and others, l990c). Current meters 

were deployed at fixed locations (fig. 5), and hydrographic 

surveys were conducted to collect data for characterization 

of the flow regime over the Farallon slope. Underwater 

video and bottom still photographs were collected to assess 

the benthic and epibenthic communities and surficial sedi-
Figure 4. Shaded relief image showing Gulf of the Farallones National Marine Sanctuary, vessel traffic lanes, navy 

munitions disposal sites, submarine operating areas, radioactive waste disposal site, and EPA study areas in threedimensions looking toward the southeast. 

ment. Epifaunal and fisheries trawl surveys were conducted 

to characterize those resources. Marine bird and mammal 

surveys were also conducted during the 1990 preliminary 

survey and the 1991 hydrographic cruises. Existing data for 

fisheries and marine birds and mammals are also being 

analyzed. 

CONCLUSIONS 

Preliminary surveys conducted by the USGS in 1990 

provided new geological and geophysical data for the 

continental slope west of San Francisco. This information, 

including sidescan sonar images, has been incorporated into 

a GIS data base in which coverages can be overlayed. As 

other information becomes available from ongoing studies, 

such as benthic communities, fisheries resources, and 

marine bird and mammal distributions, the GIS data bases 

will be updated and new coverages created. The GIS system 

has the capability to manipulate coverages and create 

two-dimensional and three-dimensional images. This 

enables technical analysts and managers to better assess the 

potential environmental impacts of ocean disposal in the 

study areas. 

The Use of Geographical Information Systems (GIS) to Facilitate Ocean Site Designation for Disposal of Harbor Dredged Materials 141 
3G.5°N 

122.5°W 

123.5° w 

Figure 5. Shaded relief image with EPA study areas , and current meter and gravity core sites in three-dimensions looking 

toward the southeast. 

ACKNOWLEDGMENTS 

We thank the efforts of Ms. Libby Prueher, Mrs. 

Rani Nandiwada, and Mr. Chip Stevens of the USGS for 

their image processing and photographic support. Other 

members of EPA Region IX, Marine Protection Section , 

working on the LTMS project are Ms. Shelley Clarke and 

Ms. Janet Hashimoto, whose knowledge and support was 

invaluable. The authors also thank Mr. Patrick Cotter and 

Mr. Terrence Fleming of EPA, Dr. Herman Karl and Mr. 

John Chin of the USGS , and Ms. Joyce M. Swanson for 

their critical review of this paper. 

142 Proceedings, 1991 EEZ Symposium on Mapping and Research 

REFERENCES CITED 

Chavez, P.S. Jr., 1984, United States Mini Image Processing 

System (MIPS): U.S . Geological Survey Open-File Report 

84-880, p. 12. 

- - 1986, Processing techniques for digital sonar images from 

GLORIA: Photogrammetric Engineering and Remote Sensing, v. 52, no. 8, p. 1133-1145. 

Chin, J.L. , Rubin , D.M. , Karl, H.A., Schwab, W.C., and 

Twichell, D.C., 1989, Cruise report for the Gulf of the 

Farallones cruise Fl-89-NC, F2-89-NC off the San Francisco Bay area: U.S. Geological Survey Open-File Report 

89-317' p. 4. 
EEZ-SCAN 84 Scientific Staff, 1986, Atlas of the Exclusive 

Economic Zone Western Conterminous United States: U.S. 

Geological Survey Miscellaneous Investigation Series 

1-1792, p. 152, scale 1:500,000 

EPA Region IX, 1991, Long-term management strategy (LTMS), 

San Francisco Bay, Ocean study plan: Prepared by EPA 

Region IX with the assistance of Science Applications International Corporation, p. 98, 2 appendixes. 

Karl, H.A., Drake, D.E., Schwab, W.C., and Chin, J.L., 1990a, 

Preliminary interpretation-Sidescan sonar mosaic and highresolution seismic-reflection profiles-Farallon Escarpment, 

Cruises F7-90-NC and F8-90-NC, 19 July-17 August, 

1990: U.S. Geological Survey Administrative Report, p. 5. 

Karl, H.A., Drake, D.E., Schwab, W.C., Edwards, B.D., Lee, 

H.J., and Chin, J.L., 1990c, Progress report on status of 

analysis and interpretation of data collected on cruises 

F8-90-NC, Farallon Escarpment, 19 July to 3 August and 5 

to 17 August, 1990: Administrative Report, p. 15. 

Karl, H.A., Schwab, W.C., and Drake, D.E., 1990b, Preliminary 

cruise report for Federal Agency cooperative cruisesF7-90-NC and F8-90-NC, 19 July-17 August, 1990: 

Administrative report, p. 10. 

Maher, N.M., Karl, H.A., Chin, J.L., and Schwab, W.C., 1991, 

Station locations and grain-size analysis of surficial sediment 

samples collected on the continental shelf, Gulf of the 

Farallones during Cruise F2-89-NC, January 1989: U.S. 

Geological Survey Open-File Report 91-375A, p. 42. 

Noble, M., and Gelfenbaum, G., 1990, A pilot study of currents 

and suspended sediment in the Gulf of the Farallones: U.S. 

Geological Survey Open-File Report 90--476, p. 40. 

Wakeman, T., and Chase, T., 1990, U.S. Army Corps of 

Engineers Issue paper on dredged material disposal in San 

Francisco Bay. 

The Use of Geographical Information Systems (GIS) to Facilitate Ocean Site Designation for Disposal of Harbor Dredged Materials 143 
Deep Sea Rock Drill- Beginning a New Era of Sea-Floor 

Sampling 

Brian Halbert 

University of Washington 

The University of Washington's Deep Sea Rock Drill 

(DSRD) was designed and built by Williamson and Associates of Seattle, Wash. Funds for drill construction and the 

development of a regional facility were provided to the 

University of Washington by the National Science Foundation, the Office of Naval Research, and Sea Grant in 1989 

and 1990. The drill is a portable tool for sampling 3 m of 

vertically oriented hard rock from the sea floor (fig. 1). This 

system consists of a 12 HP AC motor that drives two 

hydraulic pumps providing drill rotation and down pressure 

as well as platform leveling and other hydraulic functions. 

Diamond bits used on the drill generate a core that is 44.5 

mm in diameter with a 54.0-cm-deep hole. 

Sea trials were carried out aboard the R. V. Thomas 

Washington from August 22 to September 4, 1990. Three 

successful deployments were made on the northern Juan de 

Fuca Ridge, in water depths exceeding 2,400 m. Of the 

three test sites sampled during the deepwater cruise, two 

were in fresh, newly erupted basalts near the axis and one 

was from sedimented crust that was 250,000 yr old. 

Lengths of cores recovered were (I) 53 em of basalt, (2) 42 

em of basalt from the near-axial sites-including multiple 

cooling units separated by glassy chilled margins, and (3) 

37 em of sediment and 6. 7 em of altered basalt from the 

older site. 

At the older site, 1.52 m of stiff, clay-rich sediment 

were penetrated before basalt was drilled, providing samples that could not be obtained by any other method. The 

recovery of relatively short cores resulted from jamming 

due to encountering fractured basalt and polishing of the 

diamond bit surface-problems that have been alleviated by 

use of a different bit design. 

A second set of engineering tests was conducted 

aboard the R.V. Thomas Washington from October 12-16, 

1991. This opportunity, the first for University of Washington personnel to fully assemble and use the DSRD at sea, 

also tested recent modifications including changes to the 

video lighting, wire termination, and hydraulic systems. 

The first and only successful lowering of the cores occurred 

in 145 m of water on a drowned reef just off Kawaihae 

144 Proceedings, 1991 EEZ Symposium on Mapping and Research 

............ _, __ ... - . ....__ ,. ·.. ' ..... ..... _' ..... · ..... 

~~ . .-~.-.-~ ... -r-.. · ···." . ... .. .. """~::... ..-,--...... ,c..~ · .... or ...... 

,, ... ···· .. 

. -~.:... ... • .... · ' · ... 

~c: .a:."<:: ::·>·;. •. . . . . .. ~·. ·.~ .. :---~~. ~--·:·~~~-=--~·:l··~ • • • • • ~ • •.. • •• Q • .. .. • .o ..• ~ .:.o.· • • .• o 

::::::::::=· =· ~-=· =-~====H====~;;·-· -=-·"-· . . • • ---

•• • 0 • 0 • 

Figure 1. Drawing of the Deep Sea Rock Drill showing 

conducting cable linkage to surface ship. 
harbor on the Big Island of Hawaii. The bit penetrated 1.9 

m of unconsolidated material of which four small fragments 

were recovered and given to Jim Moore, U.S. Geological 

Survey, for carbon content analysis. Further drilling operations were unsuccessful because of a combination of 

electrical problems related to several small breaches in the 

outer insulation of the 0.68-in coaxial cable. While the lack 

of recovered core was scientifically unsatisfying, the recent 

engineering modifications were hailed as a great success. 

Negotiations are presently underway with the Marine 

Mining Technology Center at the University of Hawaii to 

core consolidated carbonates offshore Waikiki, Oahu. The 

drilling will be completed from a barge in 60 m to 70 m of 

water and will occur during January-February 1992. 

Further modifications of the present system are 

underway so that a "push button" and reliable tool is 

available for general use in the near future. Plans for Phase 

II, a 6-m drill with the capability to deploy subsurface 

scientific instruments, and Phase III, a 50-m drill, are 

presently being developed. 

DEEP SEA ROCK DRILL FACTS 

The University of Washington's DSRD will be available for scientific work beginning in the summer of 1992. 

This information is provided to inform potential users about 

the drills capabilities, requirements, and expected costs. 

The development of a regional facility for the DSRD at the 

University of Washington is now underway; final scheduling procedures and costs will be provided to interested 

parties as soon as they are available. 

SAMPLING CAPABILITIES 

Max Coring Depth: 

Sample Diameter: 

Bore Hole Diameter: 

Coring Rate: 

Core Recovery: 

Material: 

3m 

45-36.5 mm 

54.0 mm 

4 cores/24 hours possible 

Better than 90 percent of core drilled 

Hard rock, including fresh basalts, 

crusts, sulfides, consolidated 

clays, silts, and sands 

DRILL CAPABILITIES 

Max Operating Depth: 5,000 m limited by breaking 

strength of wire 

Max Operating Slope: 20°, maintain vertical core 

Size: Tripod base, 3 m wide, 3.3 m 

high 

Weight: 1,900 kg (4,200 lbs) 

Instrumentation: B&W video 2 sec/frame with pan 

and tilt drive, a sensor suite for 

interactive control of drill 

including bit pressure, rotation 

rate, flushing pressure, tilt, 

and core depth. 

OPERATING REQUIREMENTS 

Umbilical: 

Deck Equipment: 

UNOLS 0.68 in armored coaxial cable, 

30,000-40,000 lb breaking strength 

Adequate A-frame and winching system 

4 DSRD technicians responsible for 

maintenance, drilling, and deck operations 

Personnel: 

OPERATING COSTS 

Use Day: A 24-hour period during which the top of the 

drill mast goes below the sea surface, 

excluding dock tests. $3,900.00 

Nonuse Day: A 24-hour period during which the DSRD is 

aboard a research vessel not in use, or at a 

port of destination or departure. $2,000.00 

Shipping Day: A 24-hour period during which the DSRD is 

in transit to or from the users research 

vessel. $100.00 

Travel: Users will incur all costs of shipping and 

travel expenses for both equipment and 

DSRD personnel 

For further inquiries please contact: 

(Scientific) 

Dr. H. Paul Johnson 

School of Oceanography 

WB-10 

University of Washington 

Seattle, WA 98195 

(Technical) 

Brian N. Halbert 

School of Oceanography 

WB-10 

University of Washington 

Seattle, W A 98195 

Deep Sea Rock Drill-Beginning a New Era of Sea-Floor Sampling 145 
Geologic Framework of the Washington-Oregon 

Continental Shelf-Preliminary Findings 

Deborah J. Cranswick and Kenneth A. Piper 

Minerals Management Service 

INTRODUCTION 

The Minerals Management Service (MMS), Pacific 

Outer Continental Shelf (OCS) Region, is responsible for 

evaluating the hydrocarbon resource potential of the 

Washington-Oregon Planning Area. To accomplish this, 

MMS is conducting studies of the regional geologic framework of the Washington-Oregon continental shelf. The 

geologic framework will incorporate the interpretation and 

analysis of proprietary data acquired by industry, the results 

of MMS-sponsored studies, and work published by other 

investigators. MMS will use this information to evaluate the 

hydrocarbon potential for the 1995 National Resource 

Assessment. This information will also be used as a basis 

for recommendations and decisions regarding future studies 

of areas offshore Washington and Oregon. The preliminary 

findings of the investigation are described herein. 

BACKGROUND 

There are six Neogene depocenters or subbasins 

within the elongate depositional trough along the continental shelf of Washington and Oregon. From north to south, 

they are the Cape Flattery, Willapa, Astoria, Newport, 

Coos Bay, and Cape Blanco depocenters. Previously published maps show approximate outlines of the depocenters. 

More detailed delineation is needed for evaluation of the 

regional geology and hydrocarbon potential. Areas of thick 

sediment accumulation are more likely than thin areas to 

contain substantial thicknesses of source and reservoir 

rocks. Deeply buried rocks within thick sections are likely 

to have thermally mature hydrocarbons. Thus, the depocenters are areas of hydrocarbon potential. 

Twelve exploratory wells ( 11 original and 1 redrill) 

were drilled from 10 sites on the Washington-Oregon OCS 

between April 1965 and August 1967. These wells were 

drilled on leases awarded at the October 1, 1964, lease sale. 

All leases were relinquished by November 30, 1969, and 

the well records were made public by the U.S. Geological 

Survey on December 1, 1974. Hydrocarbon shows were 

146 Proceedings, 1991 EEZ Symposium on Mapping and Research 

encountered in some wells, but none were considered to be 

economically viable at that time. 

MMS studies, as well as studies published by other 

investigators (for example, Armentrout and Suek, 1985), 

suggest that the Pacific Northwest Eocene-to-Pliocene section can be divided into four regional, unconformitybounded sequences corresponding to four depositional 

cycles; the accumulation of each sequence was preceded 

and followed by periods of erosion. Periods of interrupted 

deposition could have resulted from orogeny, global 

sea-level fluctuation, or both. The first depositional 

cycle occurred during early and middle Eocene, the 

second occurred during late Eocene through Oligocene, the 

third occurred during early and late Miocene, and the fourth 

occurred from very late Miocene through late Pliocene. 

Delineation of the Depocenters of the 

Washington-Oregon Continental Shelf 

An isochore map of the total mappable stratigraphic 

section was created to better delineate offshore depocenters 

(fig. 1). More than 7,000 line-mi of proprietary commondepth-point (CDP) seismic reflection profiles support the 

interpretation. OCS well data provide control on the selection and identification of regional horizons. The base of the 

mapped stratigraphic section through the Willapa and Coos 

Bay depocenters is indicated on sample common depth 

point seismic profiles in figure 2. North of Grays Harbor, 

Wash., the base of the section has been identified as a 14 

m.y. unconformity (Palmer and Lingley, 1989), and the 

section probably represents Neogene basin sediments. 

South of Grays Harbor, Paleogene sediments are included 

in the mapped section. 

Two-way seismic traveltime from interpreted seismic 

profiles was digitized, and a data base was created for 

MMS 's computerized surface modeling and mapping sysFigure 1. A. Washington-Oregon depocenters, OCS ..,.. 

wells and well correlation chart. Depocenter outlines 

show'n at the 6,000-ft isochore. B. Total section isochore (thickness) map. Contour interval is 3,000 ft. 
-126" 

~89 

CAPK rLArr%RY 

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Geologic Framework of the Washington-Oregon Continental Shelf-Preliminary Findings 147 
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148 Proceedings, 1991 EEZ Symposium on Mapping and Research 
tern. A velocity formula was derived from well sonic logs 

and check-shot survey data. The formula was used to 

convert time-thickness (in seconds of two-way time) to 

thickness in feet. Thickness values determined this way are 

expected to be accurate within 10 percent. Several generations of isochore contour maps were created by using 

various contour intervals and smoothing parameters. 

The final isochore map (fig. 1B) is shown with a 

contour interval of 3,000 ft. The total section ranges in 

thickness from 0 to over 20,000 ft. In figure 1A, the general 

outlines of the six depocenters are depicted in gray within 

the 6,000-ft isochore contour. A 6,000-ft thickness is 

generally considered the minimum required for thermal 

maturation and generation of oil and gas. 

The MMS total section isochore map generally agrees 

with basin outlines previously published by several investigators (for example, Braislin and others, 1971; Zieglar and 

Cassell, 1978; and Snavely, 1987). 

Correlation Chart of the Washington-Oregon 

OCS Wells 

Stratigraphic correlations between the WashingtonOregon OCS exploratory wells were established by using 

paleontologic, lithologic, and electric log data. Well cuttings and sidewall core samples from five wells (fig. 1, 

wells OCS-P 072, P 075, P 0141, P 0150, and P 0155) were 

microscopically examined to identify species of foraminifera and record their relative abundance. Both wet-sieved 

samples and picked slides were examined. The foraminiferal assemblages were tabulated, marker species identified, 

and biozones established. The paleontologic data were used 

to determine the chronostratigraphic boundaries of stratigraphic sequences. 

Paleontologic marker species are annotated on a 

well-correlation chart. Chronostratigraphic boundaries were 

picked according to the established California Cenozoic 

benthic foraminiferal biozonations (Kleinpell, 1938; Natland, 1953; and Mallory, 1959). Rau (1981) and Armentrout and others (1983) have indicated that the California 

Cenozoic biozones are directly applicable to the foraminiferal faunal succession in coastal Washington and Oregon. 

Similar paleontological data were interpreted differently by 

Bergen and Bird (1972) for onshore wells in the Ocean City 

area. Further analysis of the well data and correlation with 

onshore wells are needed to determine an appropriate 

biostratigraphic interpretation for the area offshore 

Washington-Oregon. Copies of the well-correlation chart 

are available from the author. 

The biostratigraphic and lithologic data verify the 

existence of regional unconformities between the marine 

<111111 Figure 2. Sample seismic profiles with base of total 

mappable section. A. Witlapa depocenter. B. Coos 

Bay depocenter. 

depositional cycles. Gaps in the microfossil record indicate 

missing section; the presence of oxidized (hematitic) terrestrial sediments at the cycle boundaries indicates subaerial 

erosion. 

Synthetic Seismogram-Well OCS-P 01 03 

Synthetic seismograms were generated from electrical borehole measurements to facilitate correlation of well 

data to seismic reflection profiles. The synthetic seismogram for Oregon well OCS-P 0103 is shown in figure 3 

inserted within a portion of an intersecting seismic line. The 

synthetic seismogram was generated from digitized borehole sonic and density logs. A computer program performed 

a depth-to-time conversion of the digital data, calculated 

acoustic impedance and reflectivity, and convolved a wavelet, similar to that of the actual seismic data, with the 

reflectivity values. The resulting synthetic seismogram is a 

normal-polarity trace having no multiples (fig. 3). 

Direct comparison of the synthetic with the actual 

seismic response reveals good correlation of reflectors. A 

pronounced angular unconformity between 1.0 second and 

1.1 second on the seismic profile corresponds to a moderately strong reflector on the synthetic seismogram. Strong 

reflectors at 1.2 second to 1.3 second and 2.3 second to 2.4 

second on the seismic profile also correlate well with the 

synthetic seismogram. These high reflectivity events have 

been identified from the drilling samples as volcanic units. 

FUTURE WORK 

MMS is continuing its evaluation of the regional 

geology of the Washington-Oregon OCS. All available 

CDP seismic reflection data will be used to interpret 

intermediate horizons. Isochore maps will be created for 

each major depositional sequence. Depth maps and structural trend maps will be made for each interpreted horizon. 

A detailed bathymetric map will be created using both 

digitized sea floor from the seismic records and National 

Oceanic and Atmospheric Administration bathymetric data. 

Other offshore wells in the area will be studied in 

detail. These studies will include paleontologic evaluation, 

lithologic examination, velocity analysis, and borehole 

electric log analysis. Further analysis of synthetic seismograms for the offshore wells may provide additional insight 

to the geologic significance of the seismic signature of these 

rocks. A study is planned to correlate the offshore wells to 

onshore wells. Examination of the offshore well samples for 

nannoplankton and other microfossils is also under consideration. 

Geologic Framework of the Washington-Oregon Continental Shelf-Preliminary Findings 149 
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REFERENCES CITED 

Armentrout, J.M., and others, 1983, Correlation of Cenozoic 

stratigraphic units of western Oregon and Washington: Oregon Department of Geology and Mineral Industries, Oil and 

Gas Investigation 7, 90 p. 

Armentrout, J.M., and Suek, D.H., 1985, Hydrocarbon exploration in western Oregon and Washington: American Association of Petroleum Geologists Bulletin, v. 69, no. 4, p. 

627-643 

Bergen, F.W., and Bird, K.J., 1972, The biostratigraphy of the 

Ocean City area, Washington: Pacific Section Society of 

Economic Paleontologist and Mineralogists, p. 173-187. 

Braislin, D.B., Hastings, D.D., and Snavely, P.D., Jr., 1971, 

Petroleum potential of western Oregon and Washington and 

adjacent continental margin, in Cram, I. H., ed., Future 

petroleum provinces of the United States-Their geology and 

potential: American Association of Petroleum Geologists 

Memoir 15, p. 232. 

Kleinpell, R. M., 1938, Miocene stratigraphy of California: Tulsa, 

Okla., American Association of Petroleum Geologists, 

450 p. 

Mallory, V. S., 1959, Lower Tertiary biostratigraphy of the 

California Coast Ranges: Tulsa, Okla., American Association of Petroleum Geologists, 416 p. 

Natland, M.L., 1953, Pleistocene and Pliocene stratigraphy of 

southern California [abs.]: Pacific Petroleum Geology Newsletter, v. 7, no. 2, p. 2 (correlation chart). 

Palmer, S.P., andLingley, W.S., Jr., 1989, Anassessmentofthe 

oil and gas potential of the Washington Outer Continental 

Shelf: Washington Sea Grant Program, 84 p. 

Rau, W. W., 1981, Pacific Northwest Tertiary benthic foraminiferal biostratigraphic framework- An overview, in Armentrout, J .M., ed., Pacific Northwest Cenozoic biostratigraphy: 

Geologic Society of America Special Paper 184, p. 67-84. 

Snavely, P. D., Jr., 1987, Tertiary geologic framework, neotectonics, and petroleum potential of the Oregon-Washington 

continental margin, in Scholl, D.W., Grantz, A., and Vedder, J.G., eds., Geology and resource potential of the 

continental margin of western North America and adjacent 

ocean basins-Beaufort Sea to Baja California: CircumPacific Council for Energy and Mineral Resources, Earth 

Science Series, v. 6, chap. 14, p. 307. 

Zieglar, D.L., and Cassell, J.K., 1978, A synthesis of OCS well 

information, offshore central and northern California, Oregon, and Washington, in Hill, F.L., Wilkerson, E.R., and 

Schneider, R.H., coordinators, Energy exploration and politics (pre-print): California Division of Oil and Gas, p. 13. 

Geologic Framework of the Washington-Oregon Continental Shelf-Preliminary Findings 151 
Pacific EEZ Marine Minerals Activities of the Minerals 

Management ·service 

Roger V. Amato 

Minerals Management Service 

Abstract 

The Minerals Management Service has sponsored 

projects in four areas of the Pacific Exclusive Economic 

Zone: Hawaii-johnston Island, Gorda Ridge (offshore California and Oregon), Norton Sound (offshore Nome, 

Alaska), and an area off southern Oregon between Capes 

Sebastian and Blanco. The Hawaii-johnston Island Task 

Force was organized in 1984 to study the feasibility of 

mining cobalt-rich manganese crusts associated with seamounts. The task force sponsored several research cruises 

to gather resource data and also prepared an environmental impact statement for a possible future lease sale. The 

Gorda Ridge Task Force, also begun in 1984, funded a 

series of deep dives by a manned submersible to obtain 

samples and other data. The task force disbanded in 1988 

due to lack of industry interest. A Federal-State Coordination Team was set up in 1987 to prepare for a possible 

lease sale for gold placer sands in Norton Sound, Alaska. 

Leases were offered for sale in july 1991, but the sale and 

coordination team effort were cancelled because of the 

lack of industry bids. The Oregon Placer Minerals Task 

Force, organized in 1988, completed a research cruise in 

1990 to gather information on possible titanium-rich 

placer deposits off southern Oregon. The cruise data did 

not show evidence of commercially valuable deposits, and 

the task force was dissolved in early 1992. 

INTRODUCTION 

The marine minerals program of the Minerals Management Service (MMS) was organized shortly after President Reagan, in March 1983, declared an Exclusive Economic Zone (EEZ) for the United States. MMS marine 

minerals activities include sponsorship of mineral resource 

and environmental data collection and analysis, comprehensive scientific investigations, and economic analyses. MMS 

has sponsored projects in four areas of the Pacific EEZ: 

Hawaii-Johnston Island, Gorda Ridge (offshore California 

and Oregon), Norton Sound (offshore Nome, Alaska), and 

an area off southern Oregon between Capes Sebastian and 

Blanco. Although three out of the four projects are now 

152 Proceedings, 1991 EEZ Symposium on Mapping and Research 

inactive, many significant new discoveries were made from 

these investigations. Large amounts of data were collected 

and analyzed that increased by orders of magnitude the 

knowledge and understanding of these frontier areas. 

HAWAII-JOHNSTON ISLAND TASK FORCE 

The Hawaii-Johnston Island Task Force was established in 1984 in response to industry interest in developing 

the cobalt-rich manganese crust deposits. These deposits lie 

on the sea floor around both the Hawaiian Island Archipelago and Johnston Island. They occur in the form of crusts 

and pavements of oxide minerals on the flanks of the 

volcanically formed islands and seamounts in water depths 

of between 800 m and 2,400 m. Estimates of the potential 

metal resources in the proposed lease sale area are 2. 6 

million metric tons of cobalt, 1.6 million metric tons of 

nickel, and 81 million metric tons of manganese. Up to 2 

parts per million of platinum are also associated with the 

deposits (MMS and Hawaii, 1990). Figure 1 shows the 

potential marine mining lease tracts in the EEZ adjacent to 

Hawaii and Johnston Island. 

A Notice of Intent to prepare an Environmental 

Impact Statement (EIS) was issued with a request for public 

comment. Scoping meetings were conducted, and a Call for 

Information was published to gather ideas and available 

data for the EIS. Research cruises consisting of three trips 

over a 47-day span were completed by the University of 

Hawaii. Research and technology requirements for crust 

recovery were also examined at a development scenario 

workshop. In 1985, a revised Notice of Intent to prepare an 

EIS and a Call for Information were published specifically 

to include the EEZ adjacent to Johnston Island, and a 

second set of scoping meetings was held. A research cruise, 

mostly supported by the U.S. Bureau of Mines, was 

conducted by the R.V. Farnella to determine the potential 

mineral resources in the EEZ adjacent to Johnston Island. 

Additional resource data were acquired by the R. V. Moana 
I=:J POTENTIAL LEASE TRACTS 

I=:J AREAS EXCLUDED FOR 

ENVIRONMENTAL 

REASONS 

~ AREASEXCLUDED 

FOR MILITARY 

REASONS 

100 0 200 km L...J__J 

170" 

Figure 1. Potential marine mining lease tracts in the EEZ adjacent to Hawaii and Johnston Island. 

Wave in the area of Cross Seamount. In 1986, the German 

R. V. Sonne investigated the occurrence and distribution of 

manganese crusts in the vicinity of Johnston Island, about 

1,200 km southwest of the Island of Oahu. 

An Area Identification outlining a potential sale area 

was completed and approved in 1986, and favorable opinions on the area were received from the Fish and Wildlife 

Service and the National Marine Fisheries Service. A 

Mining Development Scenario, based on the results of the 

earlier work, was published by the State of Hawaii (Hawaii 

and MMS, 1987), along with a draft EIS. 

The task force's joint arrangement concept was 

expanded in 1988 through a cooperative agreement titled 

"Marine Minerals Joint Planning Review." This agreement 

established a Joint Planning Arrangement (JPA) with two 

committees: A Cooperative Steering Committee to address 

program and policy issues, and a Coordination Committee 

to coordinate activities and provide technical support for the 

program. 

Recommendations from the JP A committees included 

preparation of a public information brochure to communicate JPA goals and accomplishments of the EIS process, 

publication of a Request for Information to assess the 

marine mining industry's interest in the Hawaii-Johnston 

Island area, sponsorship of a workshop to determine information needs of the industry, and investigations of benthic 

repopulation and effects of suspended solids from mining. 

The final EIS for the possible future development of 

cobalt-rich manganese crusts adjacent to Hawaii and 

Johnston Island was completed (MMS and Hawaii, 1990). 

An assessment of industry interest and future requirements is anticipated by June 1992. The Task Force agreed 

to first contact prospective industry representatives by 

letter, and based on the level of response, design and 

conduct a workshop later in the year. The workshop will 

present recent studies by various academic institutions and 

the Marine Minerals Technology Center. In September 

1991, the State of Hawaii submitted a proposal to MMS to 

conduct additional resource and environmental studies on 

the crusts under the JP A. These studies are to be conducted 

in 1992-93 in the EEZ adjacent to Johnston Island, using 

vessels of opportunity. The proposed studies would generPacific EEZ Marine Minerals Activities of the Minerals Management Service 153 
ate data on the benthic current regime and habitat composition of potential mine sites. 

GORDA RIDGE POLYMETALLIC SULFIDES 

TASK FORCE 

A joint Federal-State Task Force was established with 

the States of Oregon and California in 1984 to assess the 

resource potential of the Gorda Ridge (fig. 2). Gorda Ridge 

is a series of sea-floor volcanic vents that lie about 150 mi 

off the California-Oregon coast. The ridge contains polymetallic sulfide minerals including zinc, copper, iron, and 

lead, along with small quantities of silver and gold. A 

program involving heat-flow and seismic studies, as well as 

dredging, coring, undersea photography, and marine biological studies, was completed in 1985. The program 

resulted in locating areas of hydrothermal venting. and the 

successful dredging of sulfide minerals. Based on these 

discoveries, a second year of studies was conducted, and a 

draft EIS was completed (MMS, 1983). Marine scientists 

observed and sampled polymetallic sulfide deposits containing iron, zinc, lead, copper, and gold while making a series 

of deep dives with the U.S. Navy's submersible Sea Cliff. 

Extensive sulfide deposits were discovered, sampled, and 

photographed in the Escanaba Trough, offshore northern 

California. Three sulfide-rich areas were identified (fig. 2). 

Results of the 1985-86 program were presented in 

1987 at the Gorda Ridge Symposium. Based on discussions 

at the symposium, the task force developed recommendations for future studies. However, because of the lack of 

near-term industry interest, the task force recommended a 

limited deep-dive program to conclude the Gorda Ridge 

effort. In 1988, the task force coordinated a follow-up 

scientific dive program using the Sea Cliff to gain additional 

resource data and expand the environmental baseline information. Results of the dive included discovery of a spectacular field of underwater hot springs, mineral deposits, 

and unique animals. These discoveries have provided a 

natural laboratory for scientists to further research the 

formation of underwater mineral deposits, exotic life forms, 

and the effects of hot springs on the ocean environment. 

Based on information obtained by the task force and 

the continued lack of interest by industry, the task force 

concluded that polymetallic sulfides on the Gorda Ridge are 

unlikely to be a potential target for commercial development for several decades. For this reason, the 1988 dive 

program effectively concluded the Gorda Ridge Task Force 

effort and the MMS' s involvement in the program. 

NORTON SOUND, ALASKA, GOLD PLACER 

LEASE SALE PROJECT 

As a result of the Western Gold Mining Company's 

(WestGold) gold dredging operation on State leases in 

154 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Norton Sound (offshore Nome, Alaska), an extension of 

that activity into Federal waters was likely. In 1987, the 

Governor of Alaska requested that the MMS join with the 

State in evaluating the feasibility of developing gold placers 

in the Federal waters adjacent to the State leases in Norton 

Sound (fig. 3). Following a Request for Comments and 

Nominations and a Notice of Intent to Prepare an EIS, an 

Area Identification was made for 40 blocks comprising 

about 71,000 ha. A draft EIS was issued in 1988 for a 

proposed lease sale in two areas-one offshore Nome, the 

other offshore from the town of Solomon (fig. 3). Both 

areas are between 5 km and 23 km offshore and are in water 

depths of 20m to 30m. 

A concern about possible mercury contamination 

from mining the gold placers surfaced at EIS meetings. As 

a result, a workshop on mercury in the marine environment 

was held to review current knowledge of mercury levels in 

seawater, sediments, and organisms and to discuss related 

water-quality criteria and health concerns. New mercury 

and other trace metal data were acquired using state-of-theart collection and analytical techniques. Human hair samples from local natives were collected for trace metal 

analysis. The analyses showed that mercury levels were 

below World Health Organization standards and that the 

WestGold operation was not increasing mercury levels in 

the marine environment. 

The proposed sale area was reduced from 40 to 34 

blocks (approximately 59,000 ha) to avoid king crab habitats, and a draft EIS and Proposed Leasing Notice were 

released in 1990. A final EIS was completed a year later 

(MMS, 1991). WestGold' s dredging operations in State 

waters ceased in the fall of 1990 due to declining gold 

prices, and the dredge vessel Bima was put up for sale. 

Despite WestGold's decision, the MMS received indications of continued industry interest in having a lease sale. 

Because of this interest, a sale was scheduled for July 24, 

1991. However, two legal actions requesting an injunction 

to stop the sale were filed. Since no bids were received by 

the sale date, the sale was cancelled, and the injunction 

requests were dropped. Industry cited the continuing lowering of the price of gold and the high economic and 

geologic risks as reasons for not submitting bids in the sale. 

OREGON PLACER MINERALS TECHNICAL TASK 

FORCE 

The Oregon Placer Minerals Technical Task Force 

was established in 1988 to examine the economic and 

strategic importance of placer mineral deposits believed to 

occur offshore of southern Oregon. Academic research had 

Figure 2. Bathymetric map of the Gorda Ridge study ...,.. 

area. Circles indicate sulfide-rich areas sampled by 

submersible dives. 
0 

0 

100 200 KILOMETERS 

100 NAUTICAL MILES 

CONTOUR INTERVAL 200 METERS 

Pacific EEZ Marine Minerals Activities of the Minerals Management Service 155 
ALASKA 

64• E1 Norton Sound 

15' Lease Sale Area 

NQ3-7 NQ3-8 NQ3-7 Official Protraction 

Diagram Number 

- Area of R8(Jiest 

t) f ,, 54 3t. 5 0 5 10 15 20 I I I NORTON SOUND 

I<M S1lm1TE MILES 

165• 

Figure 3. Areas offered for lease in the july 1991 Norton Sound Lease Sale. 

indicated that these deposits could contain high concentrations of heavy minerals including titanium, chromium, 

gold, zirconium, and nickel. The initial focus of the task 

force was to evaluate the potential of the deposits to the 

extent that existing data permitted. In addition, the task 

force was to identify new data necessary to provide a 

definitive resource assessment and gauge near-term economic viability. A feasibility study was undertaken involving the compilation of a placer mineral resource information 

summary, an economic evaluation, an environmental 

review, a commodity market definition, and an economic 

and strategic analysis. Based on its findings, the task force 

recommended continuation of the Oregon program and 

proposed limited geological, geophysical, and biological 

studies off Cape Blanco and Gold Beach, two areas 

156 Proceedings, 1991 EEZ Symposium on Mapping and Research 

believed to have the highest placer mineral potential (fig. 

4). 

In the fall of 1990, the R. V. Aloha spent 2 weeks 

gathering data in the Cape Blanco and Gold Beach study 

areas. Activities included conducting seismic and magnetic 

surveys, drilling vibracores in both areas, gathering trawl 

and grab samples of marine life, and observing seabirds and 

marine mammals. Despite weather and equipment problems, most of the planned biological and geophysical 

studies were successfully accomplished. Four 6-m-deep 

cores were obtained in the Gold Beach area, but only one 

core, 1-m-deep, could be obtained in the Cape Blanco area 

because of high seas. The Cape Blanco sample contained 

just over 3.0 percent titanium oxide and about 0.8 percent 

chromium. However, heavy mineral values were much 
125" 124° 43·;=.....-----------r---....--------.:.;·43° 

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lower for all the other samples, and no changes in values 

with depth were observed in any of the cores. 

The task force met in October 1991 to review the final 

results of the studies and analyses. Based upon the results, 

including the low heavy-mineral values, the task force 

recommended no further studies, and the task force was 

disbanded. A final report (Oregon, 1991) summarizing the 

data gathered and analytical results was published in 

December 1991. 

REFERENCES CITED 

Hawaii Department of Planning and Economic Development and 

the Minerals Management Service (Hawaii and MMS), 1987, 

Mining development scenario for cobalt-rich manganese 

crusts in the Exclusive Economic Zones of the Hawaiian 

Archipelago and Johnston Island: Ocean Resources Branch 

Contribution no. 38, 326 p. 

Minerals Management Service (MMS), 1983, Proposed polymetallic sulfide minerals lease offering, Gorda Ridge area, 

Offshore Oregon and northern California, Draft Environmental Impact Statement: MMS EIS, 580 p. 

Minerals Management Service (MMS), 1991, Proposed Outer 

Continental Shelf mining program, Norton Sound (Alaska) 

lease sale, Final Environmental Impact Statement: EIS/EA 

MMS 90-0009, 481 p. 

Minerals Management Service and the Hawaii Department of 

Business and Economic Development (MMS and Hawaii), 

1990, Proposed marine mineral lease sale, Exclusive Economic Zone adjacent to Hawaii and Johnston Island, Final 

Environmental Impact Statement: EIS/EA MMS 90-0029, 

503 p. 

Oregon-Federal Placer Minerals Technical Task Force (Oregon), 

1991 , Preliminary resource and environmental data: Oregon 

placer minerals: Oregon Department of Geology and Mineral 

Industries, Open-File Report 0-91-02, 229 p. 

Pacific EEZ Marine Minerals Activities of the Minerals Management Service 157 

APPENDIXES 1-4 

APPENDIX 1: 

LIST OF REGISTRANTS FOR THE EXCLUSIVE ECONOMIC ZONE SYMPOSIUM 

NOVEMBER S-7, 1991 

Carol J. Alexander 

GREENPEACE 

4649 Sunnyside Avenue, N. 

Seattle, W A 98103 

Roger V. Amato 

Office of International Activities and Marine Minerals 

Minerals Management Service 

381 Elden Street 

Atrium Parkway Building 

Herndon, VA 22070 

Larry Armbruster 

Alliant Techsystems, Inc. 

6500 Harbour Heights Parkway 

MIS 4E05 

Mukilteo, W A 98275-3250 

Jim L. Bela 

Portland State University 

3412 SE 160th Avenue 

Portland, OR 97236 

Lynda B. Bellisime 

Information Systems Division 

U.S. Geological Survey 

2255 N. Gemini Drive 

Flagstaff, AZ 86001 

John L. Breckenridge 

Naval Oceanic and Atmospheric Research Laboratory 

Code 351 

Stennis Space Center, MS 39529 

Kevin T. Brown 

Systems Center 

Defense Mapping Agency 

8613 Lee Highway (Code SGE) 

Fairfax, VA 22031 

David A. Cacchione 

Chief, Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

J. Frisbee Campbell 

Seafloor Surveys International, Inc. 

1221 Kapiolani Boulevard (PH-40) 

Honolulu, HI 96814 

John J. Carey 

National Ocean Services and Coastal Zone Management 

National Oceanic and Atmospheric Administration 

1825 Connecticut Avenue, NW, Room 607 

Washington, DC 20235 

Ronald D. Carlson 

The Analytic Sciences Corporation 

12100 Sunset Hills Road 

Reston, VA 22090 

Mike Carter 

Minerals Management Service 

770 Paseo Camarillo 

Camarillo, CA 93010 

Robert R.P. Chase 

The Analytic Sciences Corporation 

55 Walkers Brook Drive 

Reading, MA 01867 

Thomas E. Chase 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Regi Chikar 

SIMRAD, Inc. 

19210 33d Avenue, W. 

Lynnwood, W A 98036 

John E. Hughes Clarke 

Ocean Mapping Group, UNB 

Department Surveying Engineering 

UNB P.O. Box 4400 

Fredericton NB E3B 5A3 

Canada 

Frank J. Cobis 

SeaBeam Instruments, Inc. 

33 Southwest Park 

Westwood, MA 02090 

Joseph M. Coddington 

Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

James Stafford Coleman 

U.S. Department of Energy 

ER-15 

Washington, DC 20585 

Deborah Cranswick 

Minerals Management Service 

770 Paseo Camarillo 

Camarillo, CA 93010 

Richard A. Crucchiola 

State Service Center for GIS 

625 Marion Street, NE. 

Salem, OR 97310 

Ytbarek Cuddus 

Western Geophysical 

10001 Richmond A venue 

Houston, TX 77252 

Appendix 1 161 
Ralph G. Currie 

Pacific Geoscience Centre 

Geological Survey of Canada 

Box 6000 

Sidney BC V8L 4B2 

Canada 

Jon L. Dasler 

David Evans & Associates, Inc. 

2828 SW. Corbett A venue 

Portland, OR 97201 

Christian de Moustier 

Scripps Institution of Oceanocraphy 

9500 Gilman Drive 

La Jolla, CA 92093-0205 

Carolyn H. Degnan 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Patricia M. DeGroot 

U.S. Geological Survey 

9242 Ashworth Avenue, N., #202A 

Seattle, WA 98103 

Don Doyle 

Naval Oceanographic Office 

Stennis Space Center 

150 Espy Avenue 

Pass Christian, MS 39571 

David E. Drake 

Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Alice R. Drew 

Mapping and Survey Group 

Minerals Management Service 

P.O. Box 25165, MS 4421 

Denver Federal Center 

Denver, CO 80225 

Mavis L. Driscoll 

The Analytical Sciences Corporation 

55 Walkers Brook Drive 

Reading, MA 01867 

Penny D. Dunn 

Naval Oceanographic Office 

Code PMH 

Stennis Space Center, MS 39522-5001 

Sean J. Durkin 

Oceaneering International 

116 E Y anonali 

Santa Barbara, CA 93101 

Robert P. Dziak 

OSU/CIMRS/NOAA 

NOAA/OERD 

Hatfield Marine Service Center 

Newport, OR 97365 

162 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Marty Eckes 

National Ocean Service 

National Oceanic and Atmospheric Administration 

1825 Connecticut Avenue, NW. 

Suite 607 

Washington, DC 20235 

Robert W. Embley 

NOAA/PMEL/OERD 

OSU Hatfield Marine Science Center 

Newport, OR 97365 

Doyle G. Frederick 

Associate Director 

U.S. Geological Survey 

12201 Sunrise Valley Drive, MS 102 

Reston, VA 22092 

Susan Garbini 

National Research Council 

Marine Board 

2101 Constitution Avenue 

Washington, DC 20418 

Anthony Carmen Giordano 

Office of Strategic & International Minerals, INTERMAR 

Minerals Management Service 

381 Elden Street 

Herndon, VA 22070 

Hans Gray 

McElhanney Geosurveys Ltd. 

100-780 Beatty Street 

Vancouver BC V6B 2Ml 

Canada 

Paul J. Grim 

National Ocean Service 

National Oceanic and Atmospheric Administration, 

Code N/CG 224 

Rockville, MD 20852 

Charles E. Gross 

Exclusive Economic Zone 

National Oceanic and Atmospheric Administration 

6001 Executive Boulevard 

Rockville, MD 80252 

Brian N. Halbert 

School of Oceanography, WG 10 

University of Washington 

Seattle, WA 98195 

Robert K. Hall 

Environmental Protection Agency 

Region IX 

75 Hawthorne Street 

San Francisco, CA 94105 

Chris Hancock 

SIMRAD, Inc. 

19210 33d Avenue W. 

Lynnwood, W A 98036 
Susan Lynn Hanneman 

David Evans & Associates, Inc. 

2828 SW. Corbett A venue 

Portland, OR 97201 

John Hildebrand 

Scripps Institution of Oceanography 

Univer&lly of Cah1ornia, San Diego 

A-005, 1245 SYH 

La Jolla, CA 92093 

Gary W. Hill 

Chief, Office of Energy and Marine Geology 

U.S. Geological Survey 

915 National Center 

Reston, VA 22092 

Robin T. Holcomb 

U.S. Geological Survey 

School of Oceanography, WB-10 

University of Washington 

Seattle, WA 98195 

Mark L. Holmes 

U.S. Geological Survey 

University of Washington, WB-10 

Seattle, W A 98115 

D. Eldon Hout 

Land Conservation and Development Department 

State of Oregon 

Salem, OR 97310 

Donald A. Hull 

Department of Geology and Mineral Industries 

1400 SW. Fifth Avenue, Room 910 

Portland, OR 97201 

Donald M. Hussong 

Seafloor Surveys InternatiOnal, Inc. 

2201 Alaskan Way, Suite 102 

Pier 66 

Seattle, WA 98121 

James I. Jones 

Mississippi-Alabama Sea Grant Consortium 

P.O. Box 7000 

Ocean Springs, MS 39564-7000 

Herman A. Karl 

Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Thomas E. Klocek 

Naval Warfare System 

Defense Mapping Agency 

8613 Lee Highway, Stop A-13 

Fairfax, VA 22031-2137 

Robert W. Knecht 

College of Marine Studies 

University of Delaware 

Robinson Hall (301) 

Newark, DE 19711 

Scott Lee Knepper 

1535 SE 44th 

Portland, OR 97215 

Randolph A. Koski 

Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

LaVerne D. Kulm 

College of Oceanography 

Oregon State University 

Ocean Administration Building 104 

Corvallis, OR 97331-5503 

Steven P. LaBoissere 

National Ocean Service 

National Oceanic and Atmospheric Administration 

6001 Executive Boulevard 

Rockville, MD 20850 

Gail Langran 

Intergraph Corporation 

7024 19th A venue, NE. 

Seattle, WA 98115 

Douglas L. Lockhart 

Marine Minerals Technology Center 

The University of Mississippi 

220 Old Chemistry Building 

University, MS 38677 

Millington Lockwood 

Principal Deputy 

USGS-NOAA Joint Office for Mapping and Research 

915 National Center 

Reston, VA 22092 

Donald Logan 

Alliant Techsystems, Inc. 

6500 Harbour Heights Parkway 

Mukilteo, W A 98275-4844 

Peter Lonsdale 

Scripps Institution of Oceanography 

University of California, San Diego 

A-005 1245 SVH 

La Jolla, CA 92093 

MichaelS. Loughridge 

National Oceanic and Atmospheric Administration 

325 Broadway, Mail Code E/GC3 

Boulder, CO 80303 

Dennis M. Mann 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Cheryl L. Mardock 

U.S. Bureau of Mines 

1450 Queen Avenue, SW. 

Albany, OR 97321 

Appendix 1 163 
Stephen P. Matula 

OMS, National Ocean Service 

National Oceanic and Atmospheric Administration 

600 I Executive Boulevard 

Rockville, MD 20852 

Clifford E. McLain 

Marine Development Association 

7816 Manor House Drive 

Fairfax Station, VA 22039 

Gregory McMurray 

Department of Geology and Mineral Industries 

1400 SW. Fifth Avenue, Room 910 

Portland, OR 97201 

Gerald B. Mills 

Ocean Mapping System, NOS/Coast and Geodetic Survey 

National Oceanic and Atmospheric Administration 

6001 Executive Boulevard, N/CG224 

Rockville, MD 20833 

James Moore 

John E. Chance and Associates 

RR #1, Box 101D 

Rodman, NY 13682 

James Moran 

HTC/SDP 

Defense Mapping Agency 

6500 Brookes Lane 

Washington, DC 20315 

Don Murff 

Exxon Production Research Company 

P.O. Box 2189 

Houston, TX 77001 

Jim Nielsen 

Trimble Navigation 

9750 3d Avenue, NE., S-306 

Seattle, W A 98115 

Dennis L. Olmstead 

Department of Geology and Mineral Industries 

1400 SW. 5th A venue 

910 State Office Building 

Portland, OR 97201 

Edward L. Pagh 

David Evans and Associates, Inc. 

2828 SW. Corbett A venue 

Portland, OR 97201 

Guy C. Pautot 

INFREMER 

Centre De Brest 

Geosciences 

Plouzane 29280 

France 

Debbie S. Peat 

Seafloor Surveys International, Inc. 

2201 Alaskan Way, Suite 102 

Pier 66 

Seattle, WA 98121 

164 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Lelei Peau 

American Samoa Coastal Management Program 

Pago Pago, AS 96799 

Richard B. Perry 

NOS/C&7GS, N/CG224 

Mapping and Charting Branch 

National Oceanic and Atmospheric Administration 

6001 Executive Boulevard 

Rockville, MD 20852 

R. Dale Pillsbury 

College of Oceanography 

Oregon State University 

Oceanography Administration 

Building 104 

Corvallis, OR 97331-5503 

Kenneth A. Piper 

Minerals Management Service 

Department of the Interior 

770 Paseo Camarillo 

Camarillo, CA 93010 

Lincoln Pratson 

Lamont-Doherty Geological Observatory 

Columbia University 

Palisades, NY 10964 

Stephanie L. Ross 

U.S. Geological Survey 

345 Middlefield Road 

Menlo Park, CA 94025 

J ana L. Ruhlman 

U.S. Geological Survey 

2255 N. Gemini Drive 

Flagstaff, AZ 96001 

Albert R. Rule 

Albany Research Center 

U.S. Bureau of Mines 

1450 Queen Avenue, SW. 

Albany, OR 97321 

William B.F. Ryan 

Lamont-Doherty Geological Observatory 

Columbia University 

Palisades, NY 10964 

Robert I. Sanders 

Wood Tatum Wonacott and Landis 

1001 SW. Fifth A venue 

Portland, OR 97204 

Narendra K. Saxena 

Pacific Mapping Program 

Department of Engineering 

University of Hawaii 

Holmes 336 

Honolulu, HI 96822 

William G. Schramm 

NPS,FNOC 

National Oceanic and Atmospheric Administration 

2560 Garden Road, Bldg. 4, Suite. 101 

Monterey, CA 93943 
James J. Simpson 

Scripps Institution of Oceanography 

University of California, San Diego 

MS 0237 

La Jolla, CA 92093 

John 0. Smith 

Oregon Division of State Lands 

775 Summer Street, NE. 

Salem, OR 97310 

Robert W. Smith 

U.S. Department of State 

800 Villa Ridge Road 

Falls Church, VA 22046 

Stuart M. Smith 

Geological Data Center 

Scripps Institution of Oceanography 

9500 Gilman Drive 

La Jolla, CA 92093--0223 

Parke D. Snavely, Jr. 

Branch of Pacific Marine Geology 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Richard M. Starr 

Department of Fish and Wildlife 

State of Oregon 

Hatfield Marine Science Center 

Newport, OR 97365 

Veronica L. Szikszoy 

Alliant Techsystems 

6500 Harbour Heights Parkway 

Mukilteo, WA 98275 

James C. Turner 

ECONET 

2827 NE. 30th Avenue 

Portland, OR 97212 

Robert C. Tyee 

Graduate School of Oceanography 

University of Rhode Island 

South Ferry Road 

Narrangansett, RI 02882 

John R. Wagner 

Geodynamics Corporation 

5520 Ekwill Street, Suite A 

Santa Barbara, CA 93111 

Steve Wessells 

U.S. Geological Survey 

Mail Stop 999 

345 Middlefield Road 

Menlo Park, CA 94025 

Robert J. Willard 

U.S. Bureau of Mines 

5629 Minnehaha A venue S. 

Minneapolis, MN 55417 

Jerry C. Wilson 

Williamson and Associates 

731 N. Northlake Way 

Seattle, WA 98103 

J. Robert Woolsey 

Marine Minerals Technology Center 

The University of Mississippi 

220 Old Chemistry Building 

University, MS 38677 

Cort Worthington 

U.S. Geological Survey 

345 Middlefield Road, MS 999 

Menlo Park, CA 94025 

Arthur St. C. Wright 

Williamson and Associates, Inc. 

Oceanography and Marine Geophysics 

731 N. Northlake Way, Suite 104 

Seattle, WA 98103 

Rear Adm. J. Austin Yeager 

Coast and Geodetic Survey 

National Oceanic and Atmospheric Administration 

6001 Executive Boulevard 

Rockville, MD 20852 

Appendix 1 165 
APPENDIX 2: 

Working 

'lbgether 

in the 

acific 

EEZ 

Implementation of the 

National Ten-Year Plan 

for Mapping and Research 

in the Exclusive Economic 

Zone 

November 5-7, 1991 

Portland, Oregon 

166 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Symposium Sponsors 

USGS-NOAA Joint Office for Mapping 

and Research 

Association of American State Geologists 

Symposium Co-chairs 

Millington Lockwood, U.S. Department of 

Commerce, National Oceanic and 

Atmospheric Administration 

Gregory McMurray, Oregon Department of 

Geology and Mineral Industries 

Appendix 2 167 
168 Proceedings, 1991 EEZ Symposium on Mapping and Research 

Purpose and Objectives 

The purpose of the 1991 EEZ Symposium will be to focus on working relationships and partnerships for research and mapping in the Pacific 

EEZ, and how they affect implementation of the ten-year national effort to 

characterize the seafloor/subsoil of the 

EEZ. 

Specific objectives include: 

• To identify priorities for seafloor 

mapping and research primarily 

in the Pacific EEZ, but in other 

regions as well; 

• To recommend specific products 

and services necessary to meet 

these priorities; 

• To summarize progress in 

seafloor mapping and research 

in the Pacific EEZ; 

• To foster discussions regarding 

the management and dissemination of data and information 

relating to the seafloor of the 

EEZ and to identify requirements for standardization and 

exchange of digital mapping 

products; and 

• To recommend regional implementation and coordination approaches including cooperative 

projects and the roles of federal, 

state, academic and the private 

sector. 
Program Agenda 

onday, November 4 

5:00 ·9:00pm. Registration at the Portland Hilton Broadway desk 

ExlnDi.t set up in the Galleria 

esday, November5 

8:00am Registration-In the Bose Boom Foyer 

Coffee and doughnuts available in the Galleria 

9:00am In the Bose Room 

Welcome to the 5thBiennialEEZ Symposium: 

Host DorwldA Hull, Oregon State Geologist, on behalf of the 

Association of American State Geologists and the Offioo of the Governor 

9-.30-11:45 am Session I .. Policy Issues and Implementation 

Strategies 

Session Moderator: 

Gary W. Hill, Chief: USGS-NOAA Joint Offioo for Mapping and Research 

and Chief: Offioo ofEnergy and Marine Geology, USGS 

Dayle G. Fretkriek, Associate Director, USGS-

"The Role of the USGSinEEZ Mapping and Research" 

John Carey, Acting Assistant Administrator, National Ocean 

Services and Coastal7.Dne Management, NOAA-

"NOAA's Activities in the Pacific EEZ: Challenges and Choires" 

Cdr. TlwTTU:tS E. Khek, Defense Mapping Agency- "Mapping the Ocean 

Floor from the DMA/Defense Hydrographic Initiative Perspective" 

10:30 am Break-Refresbments in the Galleria 

NarendraK Saxena, Director, Pacific Mapping Program, 

University ofHawaii- "Pacific Mapping Program at the University of 

Hawaii" 

John E. Hughes Clarke, Gerard Costello, Larry A Mayer and David E. 

Wells, University ofNew Brunswick- "'rean Mapping: A Canadian 

Perspective" 

Donrild M. Hussong, Seafloor Surveys International- "Commercial 

Seabed Surveys in the U.S. EEZ and Issues Associated with the 

Distribution of these Data" 

Noon-1:30pm Lunch (Onyourown) 

Appendix 2 169 
1:30pm 

3:00pm 

6!00- 8:00pm 

Session II -Mapping aDd R,eseareh on the Seafloor 

of the EEZ in the Paeifie 

Session Moderator: 

Millington Lockwood, Deputy, USGS-NOAA Joint Office for 

Mapping and Research 

Parke D. S1UJ1Jely, Jr., USGS- "Cenozoic Geologic History of 

the Continental Margin Off Oregon and Washington" 

La Verne D. Kulm, Oregon State University- "Strike-Slip 

Faults Associated with the Casmdia Convergenre Zone off 

Oregon" 

Rnbert Embley, Pacific Marine Environmental Laboratories, 

NOAA- "The NOAA VENTS Program: Interdisciplinary 

Studies ofHydrothermal Proresses on the Juan de Fuca 

Ridge" 

John Hildebrand ani1 Spahr C. Webb, Scripps Institution of 

Oceanography, ani1 Christoph£r G. Fox, NO.ANPMEL -

"Joint SIO/NOAA Geophysical Studies on the Southern Juan 

de Fuca Ridge" 

Break-Refreshmenis in the Galleria 

Gerald Mills ani1 Richard B. Perry, NOAA- "NOAA's Multibeam Bathymetric Swveys and Products offHawaii and 

the Northeast Pacific Margin" 

DavidA CacchioTU!, USGS- "GIDRIAMappingin the Pacific 

Basin" 

Rolph G. Currie, E.E. Doois and B.S. Sawyer, Geological 

Survey of Canada, Pacific Geoscience Center- "Seafloor 

Mapping of the Western Canadian EEZ" 

Peter Lonsdale, Scripps Institution of Oceanography- "Scripps 

Institution's Multi-beam and Magnetic Mapping West of Cali 

fomia and Baja California" 

Arthur St. C. Wright, Williamson & Associates, Inc.,- "Deep 

Towed Swath Bathymetry by an Inteiferometric Isophase 

Method" 

* &ceptiDn, lunchoon, refreshments during breaks ani1 a copy ofth£ proceedings are included in the 

registroJ;iDn fee. 

170 Proceedings, 1991 EEZ Symposium on Mapping and Research 
dnesday, November 6 

8:00. 9:00am 

9:00am 

10:45 

Noon-1pm 

1:30.4:30 pm 

Coffee and dougbnu1s in the Galleria 

In the Rose Room 

lntro,duetion to Second Day of the Symposium: 

William BR Ryan, Lamont Doherty Geologiml Obsezvatmy and National 

Research Council Marine Board Committee on EEZ Information Needs-

"Data Needs and Issues Overview ofNational Research Council 

Committee Results" 

Session III • Resource Potential, Ocean Uses and 

Environmelltal and Regulatory Considerations 

Session Moderator: 

Gregory McMurray, Oregon Department ofGeolJJgy and Mineral Industries 

D. EldnnHout, OooanProgram Manager, Oregon Department ofLand 

Conservation and Development -"Oregon's Oooan Plan, 

An Emerging State OooanProgram and Information Needs" 

Clifford E. McClain, Consultant - "Resouroo Potm.tial ofOffSbote 

Plaoor Deposits" 

Break-Refresbmenm in the Galleria 

Antlwny C. Giordano, :Minerals Management Servire-'The Norton 

Sound Alaska Hard Mineral Lease" 

Richard M. Starr and Dennis Olmstead, Oregon Deparbnent ofFish and 

Wildlife and Department of Geology and Mineral Industries- "Geologiml 

and Biological Investigations ofOregons Nearshore Plaoor Deposits" 

HerrrumA Karl, USGS- "'ffshore Geology of the 

Farallones Region Project: A Model for Environmental 

Research on the Continental Margin offMajor Urban Areas" 

Symposium Luncheon -International Club 

(included in registration fee) 

Session IV· Issues Relating to Management and 

Dissemination_ of Seafloor Da,ta and Information 

(this session will be a lead in to the workshop on data 11ll111l1geT1lO tdu!du1ed for 'l'luJnda,y 

morning 9am-noonJ 

Session Moderators: 

Robert C. Tyee, University ofRhode Island and Robert Chase, The Analytical 

Sciences Corporation 

Appendix 2 171 
Alice R Drew, l\1inera1s Management Service- "'lbe Minerals 

Management Service's Implementation of the North American 

Datum of1983 in the EEZ-Implimtions for Long-Term Sharing 

and Usability ofSeafloor Data" 

Paul J. Grim, Ocean Mapping Section, NOAA- "Dissemination 

ofNOAAINOS EEZ Multibeam Bathymetric Data" 

LincolnPratson and William BR Ryan, Lamont Doherty 

Geological ObseiVatmy- "Appliartions of Computer Drainage 

Extraction Algorithms ro Multibeam Bathymetry offtbe U.S. 

Continental Margin" 

StephenP. Matula, Ocean Mapping Section, NOAA- "Bridging the Gap: Creating Nearshore Bathymetric Maps from 

Multibeam Swath Sonar SysUms and Conventional Data" 

3:00pm Break-Refresbmenm in the Galleria 

Gaillnngran and lJonTIJl J. Kall, Intergraph Corporation-

"Processing EEZ Data in a Hydrographic Geographic InformationSysrem" 

James Moran, Defense Mapping Agency- "The Defense 

Hydrographic Initiative: Solving the Digital Seafloor Mapping 

Dilemma" 

William G. Schramm,Cenrerfor Ocean Analysis and Prediction, 

NOAA- "COAP: ANew Approach ro Ocean Data Distribution" 

4:30-5:00pm ClosingComments 

(Open Microphone) 

Conclusion of formal symposium, removal of exhibits. 

Thursday, November 7 

9:00 am • noon In the Forum and Council Rooms ('lbird Floor) 

Seafloor Data an.d Information Workshop 

Workshop Moderators· 

Robert C. Tyee and Robert Chase 

This workshop will last from 9am to about noon. It is being organized by 

Robert C. Tyee and the NRC Marine Board Committee on EEZ Information 

Needs. 

The workshop will be divided up into five sections which will debate pertinent 

issues that affect the design and development of an EEZ doia and information system to serve the needs of the user community. A brief questionnaire 

will be distributed to each attendeee at the beginning of the Symposium to determine areas of interest, questions to be discussed and number of atterukes. 

Depending upon the results of the questionnaire, the participants may be 

divided into subgroups to deal with specific topics. 

172 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Workshop Description 

The National Research Council Committee on Exclusive Economic Zone Information Needs will host a Data Management Workshop designed to solicit input 

from the oceanographic community on several topics that affect the design and 

development of an EEZ data and information system. The format of the workshop will be an open forum debate with a member of the Committee assuming 

the opposing view. By proceeding in this manner, the committee expects to hear 

aired a broad range of issues and to determine how strongly workshop participants support these views. 

For the purposes of the workshop, the following topics will serve as a basis for 

initial discussion: data acquisition, data processing, data integration, data 

access and archives. Among others, specific issues of concern to the Committee 

include: 

1. Should the federal government impose standard data formats for all 

data sets that will be placed in EEZ data archives, or would it be preferable for those individuals adding data to the archives to define the specific 

format used for a particular data set? 

2. Should the federal government impose standards on instrumentation 

and on data collection procedures for all data acquired in the EEZ and 

destined for EEZ data archives, or would it be better for those individuals 

acquiring data to use instruments of their own choice and develop their 

own data collection procedures? 

3. Should the government plan to preprocess various EEZ data sets prior 

to distribution, providing only preprocessed data subsets, or should fullresolution, "raw" data be made readily available to end users? 

4. In the preprocessing of data from the EEZ archives, should the federal 

government use only algorithms that have been preselected (either by the 

government or a user group), or should the government plan for "processing on the fly" using algorithms defined by the end users themselves? 

5. Because of the broad suite of instruments used to collect data within 

the E·Ez, there will be a mixture of raster and vector data available; 

should the government attempt to integrate these data types (e.g., via a 

common GIS representation)? 

6. For either data type of interest (i.e., either vector or raster), should the 

government pursue a common integrated data base approach, or should it 

plan to provide users with only individual, unbundled data sets? 

Appendix 2 173 
7. As a means for providing users with knowledge of archival holdings, 

the government could periodically publish hardcopy (paper) catalogues for 

distribution; alternatively, an on-line electronic catalog could be developed 

to support user query requirements. Are there preferences one way or the 

other within the user community? 

8. Any and all EEZ data could be provided as analog representations (i.e., 

charts) or as mmtal data subsets (or for that matter as some, yet undefined, admixture of these data types). From the users' perspective, is 

there any apriori reason to select one data type over the other? 

9. Archival data holdings could be preprocessed and virtually ready for 

shipment to end users upon request. Alternatively, these data might be 

stored in raw form only and processed on demand. Processing on demand 

might well increase the time needed to respond to a. user's data request. 

Is response time a critical issue for EEZ data users? 

10. In an era of broad band electronic communications networks, centralized versus distributed archives is oflittle functional consequence. Some 

concerns have been expressed, however, that a central archive might not 

optimally serve users from various regions of the country. Geographically-distributed archives could be organized around instrument-type or 

be of topical interest to a given region. Is there a consensus within the 

community for centralized or distributed archives? 

The Committee on EEZ Information Needs recognizes that these issues 

are but a small subset of those that are of concern to EEZ data users. 

Consequently, the Committee enthusiastically encourages all workshop 

participants to air their views on any issue associated with the acquisition, processing, archival, and distribution ofEEZ data. 

174 Proceedings, 1991 EEZ Symposium on Mapping and Research 
Poster Displays and Exhibits 

Robin Holcomb 

David E. Drake 

Randolph Koski 

Herman Karl, 

Tom Chase 

Joseph Coddington 

Paul J. Grim 

Robert K. Hall 

Brian Halbert 

Robert Embley, 

Robert Dziak 

Debbie Peat 

Deborah Cranswick 

Roger V. Amato 

Scott E. Smith 

GLORIA mosaic and Geologic Map of the Hawaiian EEZ 

Johnston Island GLORIA Mosaic 

Geologic Setting and Hydrothermal Deposits at Escanaba 

Trough, Southern Gorda Ridge 

Offshore Geology of the Farallones Region Project - Assessing 

Man's Impact on the Environment 

The Exclusive Economic Zone Atlases- The EEZ on CD-ROM 

Multibeam Mapping of the U.S. Exclusive Economic Zone in 

the Pacific EEZ 

The Use of GIS to Determine Site Designation for Ocean Disposal of Harbor Dredge Materials 

The University of Washington's Deep Sea Rock Drill: 

Beginning a New Era of Sea Floor Samping 

The Blanco Transform Fault Zone - An Active Strike-Slip 

Plate Boundary in the U.S. EEZ 

Commercial Swath Bathymetry and Sidescan Sonar Mapping 

Regional Geologic Framework Along the Washington-Oregon 

Continental Shelf: Preliminary Results 

MMS Marine Mineral Activities in the Pacific EEZ 

A GIS for Ocean Management 

Appendix 2 175 
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176 Proceedings, 1991 EEZ Symposium on Mapping and Research 

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Abstracts 

In alphabetical order by author. 

GLORIA MAPPING IN THE PACIFIC BASIN 

DavidA Cacchione, Branch of Pacific Marine Geology, U.S. Geological Survey, 345 

Middlefield Road, MS-999, Menlo Park, California 94025 

The mapping program of the U.S. EEZ that was initiated in 1984 using the 

GLORIA side-scan sonar system is nearing a major milestone. The final cruise 

to obtain GLORIA data in the EEZ around the 50 United States will be completed in 1991. Atlases of the EEZ off California, Oregon and Washington, and 

in the Bering Sea are now published and available to the public, and GLORIA 

and ancillary geophysical data from the other Alaskan and Hawaiian regions are 

in various stages of processing and analysis. 

GLORIA mapping in the EEZs of the Pacific Island trust territories of the 

U.S. has already commenced with data collection around Johnston, Kingman 

and Palmyra Islands. Continued mapping and research in the island trust 

territories is planned for the future. 

OCEAN MAPPING: A CANADIAN PERSPECTIVE 

John E. Hughes Clarke, Gerald Costello, Larry A. Mayer and David E. Wells, Ocean 

Mapping Group, Dept. Surveying Engineering, University of New Brunswick, P.O. Box 

4400, Fredricton, N.B., E3B 5A7, Canada 

Canada, with the world's longest coastline and the second largest continental 

shelf, has acknowledged the need for developing a strategy for acquiring, handling 

and disseminating high-volume ocean mapping data. To meet this need Canada has 

embarked on several initiatives designed to bring together government, industry 

and universities. Two examples of the initiatives are: 

1. The establishment of the Industrial Research Chair in Ocean Mapping at 

the University of New Brunswick, and 

2. The Canadian Ocean Mapping (COMS), a project integrating multibeam 

sonars, robotic vehicles and advanced data processing techniques. 

These programs will be briefly described and current ocean mapping activities, related to these initiatives, will be discussed. 

Appendix 2 177 
SEAFLOOR MAPPING OF THE WESTERN CANADIAN EXCLUSIVE 

ECONOMIC ZONE 

R. G. Currie, E. E. Davis and B.S. Sawyer, Pacific Geoscience Centre, Geological Survey of Canada, Box 6000, Sidney, B.C., V8L 4B2, Canada 

Various geophysical mapping tools including SEABEAM, SeaMARC IliA, SeaMARC II, AMS120 and GLORIA have been used in this geologically active region of 

the northeast Pacific over the last two decades. Joint surveys between PGC, NOAA 

(with SEABEAM) and the University of Hawaii (with SeaMARC II) have been designed to provide detailed yet continuous coverage of the areas of greatest interest 

including much of the axial zone of the northern Juan de Fuca Ridge system and the 

tectonically active lower continental slope. The resultant swath bathymetry and 

acoustic imagery have been compiled and published as a series of 1:50,000 and 

1:250,000 scale maps. Areas of particular scientific interest have been surveyed 

with the higher frequency SeaMARC I, IA and/or AMS120 deeptow sidescan systems. Additional data sets available in this region include gravity, magnetics, heat 

flow, reflection and refraction seismics as well as sediment grab samples, .dredge 

samples and cores. Only first order, qualitative interpretation and integration of 

many of these data sets has occurred. The bathymetry and acoustic-image mosaics 

characterize the recent volcanism and faulting at the offshore spreading centres, 

recent off-axis seamount volcanism, sediment distributary channels and the deformation and faulting of sediments along the Queen Charlotte transform and Vancouver Island subduction plate boundaries. 

The challenges and objectives for the future include (a) the application of 

navigation systems and processing techniques to expeditiously georeference the 

imagery and (b) to ground truth the imagery. It is anticipated that erihanced presentation of accurately located data will make sidescan sonar imagery more accessible to the geological community and lead to a greater understanding of the geology 

and tectonics of the region. 

THE MINERALS MANAGEMENT SERVICE'S IMPLEMENTATION OF THE 

NORTH AMERICAN DATUM OF 1983 IN THE EEZ 

Alice R. Drew, Minerals Management Service/Mapping & Survey Group, P.O. Box 

25145, MS 4421, Denver Federal Center, Denver, CO 80225 

The Minerals Management Service (MMS) is implementing the change from 

the North American Datum of 1927 (NAD 27) to the North American Datum of 

1983 (NAD 83). NAD 83 is the official civilian horizontal datum of U.S. surveying 

and mapping activities. This was affirmed by a Federal Geodetic Control Committee mandate made on December 6, 1988. MMS' goals for its phased implementation are to develop a uniform cadastre throughout the Outer Continental Shelf 

(OCS) and to remain conversant with its constituencies. NAD 83 is the most accurate· datum ever defined for the United States. 

178 Proceedings, 1991 EEZ Symposium on Mapping and Research 
THE NOAA VENTS PROGRAM: INTERDISCIPLINARY STUDIES OF 

HYDROTHERMAL PROCESSES ON THE JUAN DE FUCA RIDGE 

Robert Embley, NOAA/PMELIOERD, OSU Hatfield Marine Science Center, Newport, 

Oregon 97365 

Since 1984, studies of the vent systems on the Juan de Fuca Ridge have been 

conducted using a closely coordinated approach incorporating a wide range of expertise. This interdisciplinary approach combined with the ready access to the 

study site off Oregon and Washington has yielded some important insights into the 

oceanic hydrothermal system. One of the most fundamental discoveries is that very 

large expulsions of hydrothermal fluids (megaplumes) are linked to episodes of 

seafloor spreading. The discovery of the mega plumes led directly to the documentation of a volcanic eruption that occurred during the same period of time (mid1980s). The scientific community is now developing plans for a seafloor observatory 

and long-term monitoring of portions of the Juan de Fuca Ridge, so this area is 

likely to remain a focus of research for many years. 

THE NORTON SOUND ALASKA MARINE MINERAL OFFSHORE LEASE 

SALE 

Anthony C. Giordano, Minerals Management Service, INTERMAR, 381 Elden Street, 

MS-4030, Herndon, Virginia 22070 

In March and June 1991, the Minerals Management Service published a final 

Environmental Impact Statement and Final Notice of Sale for a Federal offshore 

mineral lease sale in Alaska's Norton Sound. The sale was scheduled for July 24, 

1991. The sale area focuses on acreage that has the highest potential for placer gold 

and covers 34 whole and partial blocks encompassing about 14 7,000 acres. The 

area is located between 3 and 14 miles offshore Nome in water depths ranging from 

66 to 99 feet. The Sale Notice outlines the terms and conditions of the sale and 

contains restrictions on the operations in the form of stipulations and Information 

to the Lessees clauses. The restrictions provide environmental protection and 

respond to concerns expressed during the prelease process. The history of gold 

mining in Nome leading up to the lease sale and the unique prelease process developed for the sale will be discussed. 

Appendix 2 179 
DISSEMINATION OF NOAA/NOS EEZ MULTIBEAM BATHYMETRIC DATA 

Paul J. Grim, Code N/CG224, NOAA/NOS, Rockville, Maryland 20852 

NOAA/NOS disseminates multibeam bathymetric gridded data for the U.S. 

EEZ. All data for a map area, measuring 0.5 degrees in latitude by 1 degree in 

longitude, are in an ASCII format. They are contained on a single floppy disk that 

can be read by a PC. Two types of grids, covering the same area, are contained on 

the disk. The first, used to produce the contours on the standard 1:100,000 scale 

map, is based on UTM coordinates and has a grid spacing of 250 meters. The second grid is less dense than the UTM grid from which it is derived. This "geographic" grid has a spacing of 15 seconds in both latitude and longitude directions. 

NOS is also providing "full resolution" multibeam data to NOAA's National Geophysical Data Center which will make them available to the public. 

JOINT SIO/NOAA GEOPHYSICAL STUDIES ON THE SOU'rHERN JUAN DE 

FUCA RIDGE 

John A Hildebrand, and Spahr C. Webb, Scripps Institution of Oceanography, UCSD, 

La Jolla, California, 92093 and Christopher G. Fox, NOAA-PMEL, Hatfield Marine Science Center, Newport, Oregon 97365 

We present results from a suite of geophysical experiments conducted on the 

southern Juan de Fuca Ridge by the NOAA VENTS program. During these geophysical experiments we looked for evidence of continuing seafloor volcanic activity 

at the Axial Volcano and the Megaplume sites on the southern Juan de Fuca Ridge. 

These experiments will become major components of doctoral theses of three graduate students at SIO. The geophysical studies allow the structure of seafloor magmatic and hydrothermal circulation to be delimited, providing constraints on the 

relationship of structure to magmatic activity. A seismic refraction experiment, 

using ocean bottom seismographs (OBSs) and an airgun array, determined shallow 

crustal seismic velocity and attenuation by observing the propagation of seismic 

waves through the seafloor. These OBSs also recorded numerous microearthquakes along a 16 km segment of rise crest near the Megaplume site near the CleftVance overlapping rift zone. Bottom gravity stations and a surface gravity survey 

provide information on crustal density structure. Variations of seismic velocity, 

attenuation and density are related to zones of hydrothermal and magmatic activity. 

180 Proceedings, 1991 EEZ Symposium on Mapping and Research 
OREGON'S OCEAN PLAN, AN EMERGING STATE OCEAN PROGRAM AND 

INFORMATION NEEDS 

D.Eldon Hout, Ocean Program Manager, Oregon Department of Land Conservation 

and Development, 320 SW Stark Street, Room 525, Portland, Oregon 97204 

The State of Oregon, one of several coastal states addressing ocean resources 

through its coastal management program, recently adopted the Oregon Ocean 

Resources Management Plan. Legislation requiring the ocean plan set a state 

policy of co-management with federal agencies for ocean resources within the EEZ 

and recognized the need for additional ocean information for management. Oregon 

is developing a computerized ocean information system for storing and using ocean 

resource information. The Ocean Plan, adopted after lengthy public involvement, 

includes policies for a variety of ocean resources and uses across the continental 

shelf off Oregon. Throughout, the Plan identifies numerous information needs 

about ocean resources, features and conditions and outlines a general hierarchy for 

information acquisition. However, it appears that information needed for most 

ocean management decisions focuses on more "fine-grained" nearshore areas and 

resources in contrast with the broadscale, deep ocean approach of existing federal 

EEZ research programs. 

COMMERCIAL SEABED SURVEYS IN THE U.S. EEZ AND ISSUES 

ASSOCIATED WITH THE DISTRIBUTION OF THESE DATA 

Donald M. Hussong, President, Seafloor Surveys International, Inc., Pier 66-2201 

Alaskan Way, Seattle, Washington 98121 

Seafloor Surveys International has conducted a number of high-resolution 

side-scan sonar and swath bathymetry surveys for communications and power 

cables as well as fisheries evaluation within the U.S. EEZ. Over 3,500 square kilometers of high-resolution data have been collected, with 100% bathymetry coverage 

that is typically contoured at a 5 meter interval to 1000 meters depth, and a 50 

meter contour interval in deeper areas. These data are acquired and routinely 

processed into publication-quality charts following IHO standards, at a commercially attractive cost. Routine mapping by commercial surveyors may provide an 

effective method to meet some national government survey objectives. 

The handling of digital swath mapping data is presently too cumbersome to 

promote responsible distribution of these data. An appropriately funded program 

should be established to standardize formats and promote distribution of these 

valuable data. 

Appendix 2 181 
OFFSHORE GEOLOGY OF THE F ABALLONES REGION PROJECT: A 

MODEL FOR ENVIRONMENTAL RESEARCH ON CONTINENTAL MARGINS 

OFF MAJOR URBAN AREAS 

Herman Karl, U. S. Geological Survey, 345 Middlefield Rd, MS-999, Menlo Park, 

California 94025 

The U.S. Geological Survey began a major geologic and oceanographic study 

of the Gulf of the Farallones in 1989. This investigation, the first of several now 

being conducted adjacent to major population centers, was designed to establish a 

scientific data base on a segment of continental shelf adjacent to the San Francisco 

Bay area that can be used to evaluate and monitor human impact on the marine 

environment. In 1990 the project expanded greatly in scope when the USGS conducted a multi-disciplinary investigation sponsored by USGS, the U.S. Environmental Protection Agency, the U.S. Army Corps of Engineers, the U.S. Navy, and 

the National Oceanic and Atmospheric Administration to survey and sample the 

continental slope west of the Farallon Islands. The federal agency cooperative 

study was designed to provide information on the location and distribution of 4 7,500 

containers of radioactive waste and data on areas being considered as sites for 

disposal of dredge material. 

MAPPING THE OCEAN FLOOR FROM THE DMAIDEFENSE HYDRO· 

GRAPHICnflTIA~PERSPEC~ 

Thomas E. Klocek, CDR USN, Defens~ Mapping Agency, Naval Warfare Systems Division (PRN), HQ DMA, 8613 Lee Highway, Fairfax, Virginia 22031-2137 

The Defense Hydrographic Initiative (DHI) provides formal coordination among the 

Defense Mapping Agency (DMA), Oceanographer of the Navy (CNO OP-096), and the 

National Oceanic and Atmospheric Administration/National Ocean Service (NOAA/ 

NOS) regarding the collection, processing, archiving, analysis, integration, production, 

and distribution of hydrographic and bathymetric data; and transition to support of 

digital products to the user community. 

182 Proceedings, 1991 EEZ Symposium on Mapping and Research 
STRIKE-SLIP FAULTS ASSOCIATED Wl'l'H THE CASCADIA CONVERGENCE 

ZONE OFF OREGON 

La Verne D. Kulm, College of Oceanography, Oregon State University, Oceanography 

Admin. Bldg. 104, Corvallis, Oregon 97331-5503 

Major strike-slip faults were recently discovered off Oregon using a combination of Sea Beam swath bathymetry, SeaMARC-lA sidescan sonar, and multichannel seismic records. One of these left-lateral faults occurs on the abyssal plain and 

crosses the Juan de Fuca-North American plate boundary, cutting the accretionary 

wedge. Sea Beam bathymetry illustrates several manifestations of the fault zone 

including a large abyssal hill and pop-up plateaus, a large indentation within 

wedge, and sigmoidal bending of fold axes along the trend of the fault. The implications of these faults in the plate tectonic framework of the Cascadia subduction zone 

is being studied. Swath mapping technology contributed directly to the discovery of 

these new features, whose structures were subsequently imaged with deep penetration seismics. 

PROCESSING EEZ DATA IN A HYDROGRAPHIC GEOGRAPHIC INFORMA· 

TIONSYSTEM 

Gail Langran, Intergraph Corporation, 2051 Mercator Drive, Reston, Virginia 22091-

3413 and Donna J. Kall, Intergraph Corporation, MS IW1505, Huntsville, Alabama 

35894-0001 

TIGRIS Mariner is an information system that was designed specifically to 

process and analyze hydrographic data. The system includes tools to visualize, 

analyze, perform quality control, produce statistics and reports, and select a representative subset of soundings from a dense survey. This paper will describe some of 

the TIGRIS Mariner utilities of interest to EEZ data analysis and discuss how the 

system is to be used in the new NOS nautical charting system that presently is 

under development by Intergraph Corporation. 

Appendix 2 183 
SCRIPPS INSTITUTION'S MULTIBEAM AND MAGNETIC MAPPING WEST 

OF CALIFORNIA AND BAJA CALIFORNIA 

Peter Lonsdale, Scripps Institution of Oceanography, UCSD, La Jolla, California 92093 

For the past 10 years the Scripps Institution has operated a Sea Beam 

equipped ship from its San Diego base, mostly on long..:range cruises to remote areas 

of the Pacific and South Atlantic. A substantial volume of data has also been collected on transits to and from home port, and during a few special survey cruises, 

within the U.S. and Mexican EEZs off southern California and Baja California. The 

oceanic crust in these regions was accreted 30-40 m.y. ago at part of the East Pacific 

Rise that was colliding with the North American continent and breaking up into 

complex patterns. Joint analysis ofmultibeam bathymetry and magnetic lineations 

has proved essential for untangling this structural complexity, and for identifying 

"fossil" spreading centers, transform faults and trenches that still exist offshore. 

We have devoted less effort to the region west of central and northern California 

where bathymetry is much less informative because thick sediment deposits have 

smothered the oceanic crust. In 1992 we will commence operations with a much 

more powerful Sea Beam 2000 mapping sonar, and some of the early cruises with 

this new system are scheduled for local waters. 

BRIDGING THE GAP: CREATING NEAR-SHORE BATHYMETRIC MAPS 

FROM MULTffiEAM SWATH SONAR SYSTEMS AND CONVENTIONAL DATA 

SOURCES 

Steven P. Matula, Ocean Mapping Section, NOAA, NOS, N/CG224, 6001 Executive 

Blvd., Rockville, Maryland 20852 

The main focus of the NOS Ocean Mapping Program has been to collect 

highly accurate and precisely navigated digital bathymetric data in depths deeper 

than 150 meters. Depths of these magnitudes may only partially cover continental 

shelf regions, which tend to be of particular interest to the mapping and other scientific communities. Thus, whenever possible, additional in-shore data sources are 

incorporated to supplement the multibeam survey data and provide a complete map 

depiction. This paper will discuss the current techniques used in integrating modem digital multibeam swath sonar data with additional in-shore data sources, 

conversion of supplemental digital and non-digital hydrographic survey data, methods of incorporating cartographically interpreted contour lines derived from handdigitization, raster scanning or vectorization, and outputs in both digital and analog 

forms. 

184 Proceedings, 1991 EEZ Symposium on Mapping and Research 
RESOURCE POTENTIAL OF OFFSHORE PLACER DEPOSITS 

Clifford E. McClain, Consultant, 7816 Manor House Drive, Fairfax Station, Virginia 

22039 

The resource potential of offshore placer deposits has a long history on the 

Pacific coast, particularly in Northern California, Oregon, and Alaska. Gold mining 

commenced in the latter half of the 19th century and continues in some parts today, 

most recently the WestGold operation at Nome, Alaska. Principle economic minerals include gold and PMG, chromite, ilmenite, rutile, and zircon, the potential commercial value of which may be very large. Basic exploration data exist, but the 

deposits have generally not been well characterized. Prospects for commercial 

development are significantly limited by the minerals market and by coastal resource management and environmental considerations. Within these constraints, 

near term commercial development seems unlikely, other than very limited operations such as that of WestGold. The long term resource potential of these vast 

deposits, however, seems undeniable. A new factor is the potential which these 

deposits may represent for a "strategic reserve" against future national security 

requirements, as a base for future national economic stability in a vigorous, competitive, and uncertain world socio-economic environment, rather than for military 

mobilization. 

NOAA MULTIBEAM BATHYMETRIC SURVEYS AND PRODUCTS OFF 

HAW An AND THE NORTHEAST PACIFIC MARGIN. 

Gerald B. Mills and Richard B. Perry, Ocean Mapping Section, NOS, NOAA, N/CG224, 

6001 Executive Blvd., Rockville, Maryland 20852 

The National Ocean Service multibeam mapping program has obtained total 

sounding coverage of over 100,000 square nautical miles of the U.S. Exclusive Economic Zone. Index maps show the coverage off Hawaii, Alaska, and the West Coast, 

as well as in the Gulf of Mexico and off Virginia. Fifty-six 1:100,000 bathymetric 

maps with a 20-meter contour interval, mostly covering one-half degree of latitude 

by one degree of longitude, are now available in black and white or printed form. Of 

these, 6 are off Hawaii, 4 off Alaska, 12 off Oregon, and 13 off California. As the 

maps are printed, a gridded data set also is available. New products include adimensional physiographic images covering parts of the continental margin off the 

central California coast, Louisiana, and Oregon (in compilation). New surveys off 

Hawaii are evaluating the use of differential GPS. 

Appendix 2 185 
DMA'S DEFENSE HYDROGRAPHIC JNITIATIVE AND THE DOD BATHYMETRIC DIGITAL DATA LIBRARY AND HYDROGRAPHIC SOURCE ASSESSMENT SYSTEM (HYSAS) 

James Patrick Moran, Cartographer, Defense Mapping Agency, 6500 Brookes Lane, 

MS D-56, Washington, D.C. 20315 

DMA's Defense Hydrographic Initiative is a research and development program for the modernization of collection, evaluation, and processing ofbathymetric 

data. The DOD Bathymetric Digital Data Library concept is that of a centralized 

distributed library network amongst DMA, NAVY, and NOAA. The controlling 

mechanism for this library system is HYSAS. HYSAS will provide mega data and 

area of coverage about each bathymetric source and provide instructions to the 

library management system for processing and servicing. It is planned to have 

HYSAS monitor collection activities and perform active tasking functions in the 

future. The schedule plan of action and milestones is in concert with the DMA 

Digital Production System effectivity milestones. The ultimate goal from this development is the cooperative effort amongst the library network nodes for a shoreline 

to shoreline bathymetric digital data library. 

186 Proceedings, 1991 EEZ Symposium on Mapping and Research 
~PLICATION OF DRAINAGE EX'rRACTION ALGO~ TO EEZ 

MULTIBEAM BATHYMETRY OF THE U.S. CONTINENTAL MARGIN 

Lincoln F. Pratson and Willian B.F. Ryan, Lamont-Doherty Geological Observatory, 

Columbia University, Palisades, New York 10964 

A sequence of computer algorithms is presented for use in deriving digital 

information about submarine drainage systems from rectangular-gridded, sea 

floor bathymetry. Submarine drainage systems are defined here as the networks 

of submarine canyons and channels that transport sediments to the deep-sea. 

These networks and the areas of the sea floor they drain can be automatically 

extracted from bathymetric grids using algorithms originally developed for the 

study of drainage systems formed by water runoff on land. 

Information on sediment drainage is extracted following five general steps. 

First, the gridded bathymetry is conditioned such that shallow topographic depressions segmenting connected channel-ways are infilled to ensure a continuous 

drainage network. Second, each grid cell is assigned a flow direction, which 

points towards the steepest drop in the eight neighboring elevations. Third, a 

flow accumulation is computed for each grid cell by summing the number of 

"upslope" cells linked by flow directions. The flow accumulations can then be used 

to extract drainage networks by specifying a threshold, whereby all cells with flow 

accumulations that exceed the threshold constitute part of the drainage network. 

Finally, a drainage area can be delineated by simply grouping all cells within the 

grid that have flow directions which lead to that cell designated as the point of 

outflow. The output of the routines can be quantified to yield measurements of 

channel lengths and drainage area. 

The drainage extraction routines are applied to multibeam bathymetry of 

the Exclusive Economic Zone off the coast of California and in the Gulf of Mexico 

collected and gridded by the National Oceanic and Atmospheric Administration. 

The analyses reveal that the submarine drainage systems within these areas are 

predominantly tributary rather than distributary in nature. In some cases, drainage has developed over regions of such subtle relief that these systems would 

probably not have been perceived by visual inspection alone. These results indicate drainage extraction routines could be a significant aid in the interpretation of 

bathymetric data sets for both scientific and industrial objectives. 

Appendix 2 187 
PACIFIC MAPPING PROGRAM AT THE UNIVERSITY OF HAWAII 

Narendra Saxena, Department of Civil Engineering, University of Hawaii, Honolulu, 

Hawaii 96822 

A unique Pacific Mapping Program (PMP) for data analysis and integration 

as well as for a graduate certificate in Marine Mapping, Charting and Geodesy 

(MMCG) has been initiated at the College of Engineering, University of Hawaii at 

Manoa. Its objective is to make it a REGIONAL DATA CENTER for the Pacific 

Region for (a) archiving all mapping data of Pacific Islands' EEZ, (b) processing, 

analyzing and integrating various data sets, and (c) providing training and education in ocean mapping via courses and workshops. 

COAP: A NEW APPROACH TO OCEAN DATA DISTRIBUTION 

William G. Schramm, Acting Director, Center for Ocean Analysis and Prediction, 

NOAA, 2560 Garden Road, Suite 101, Monterey, California 93940 

The NOAA Center for Ocean Analysis and Prediction in Monterey California 

has implemented a new Relational Data Base Management System for oceanographic data. The system, called NEONS, was developed by the Navy and is designed to manage images, gridded data and observational data. In addition COAP 

is implementing two new systems to provide access to the RDBMS. The first system 

called NODDS can be used with PCs and MACs and uses telephone lines for communications. The second system is intended for use with more powerful computers 

and INTERNET. 

CENOZOIC GEOLOGIC HISTORY OF THE CONTINENTAL MARGIN OF 

OREGON AND WASHINGTON 

Parke D. Snavely, Jr., U.S. Geological Survey, 345 Middlefield Rd., Menlo Park, 

California 94025 

The Cenozoic tectonic and depositional history of the Oregon and Washington 

continental margin (OWCM) was molded by underthrusting, transcurrent faulting, 

and extension during oblique subduction between North America and the oceanic 

plates to the west. Sedimentation, punctuated by episodes of volcanism, was essentially continuous in the fore-arc basin whose axis lay along the present inner continental shelf. The more than 7 km of Eocene to Miocene strata that accumulated in 

this basin contain potential source beds and reservoir rocks for petroleum. Intense 

deformation on the OWCM clearly records a prolonged history of episodic tectonism 

along this active plate boundary. Quaternary deformation, some of which possibly 

relates to seismic events, includes normal and thrust faults that offset the sea floor, 

diapirs arid anticlines that warp the sea bed, uplifted and faulted marine coastal 

terraces, and rapid subsidence of marsh deposits along the strand line. 

188 Proceedings, 1991 EEZ Symposium on Mapping and Research 
GEOLOGICAL AND BIOLOGICAL INVESTIGATIONS OF OREGON 

NEARSHORE PLACER DEPOSITS 

Richard M. Starr, Oregon Department ofFish and Wildlife, Hatfield Marine Science 

Center, Newport, Oregon 97365, and Dennis Olmstead, Oregon Department of Geology 

and Mineral Industries, 1400 SW Fifth Avenue, Portland, Oregon 97201-5528 

In 1990, the joint State-Federal Placer Minerals Technical Task Force supported a research cruise to identify the concentration and distribution of placer 

minerals, to collect information on living resources associated with placer deposits, 

and to learn more about the basic geology and biology of southern Oregon waters. 

Geological and biological sampling on the cruise proved to be complementary. Bottom grabs for benthic invertebrate analysis were used by geologists to assess concentrations of heavy minerals. Resulting sediment analyses helped biologists 

understand the distribution of invertebrate communities in the study area. Sidescanning sonar surveys proved valuable in designing biological surveys of different 

habitat types. Bird and mammal surveys were successfully conducted while the 

ship was conducting magnetic and seismic surveys. 

DEEP TOWED SWATH BATHYMETRY BY AN INTERFEROMETRIC ISOPHASE METHOD 

Arthur St. C. Wright, Williamson & Associates, Inc., Oceanography and Marine Geophysics, 731 N. Northlake Way, Suite 104, Seattle, Washington 98103 

The interaction of receiver patterns from separated parallel sidescan sonar 

transducers produces an isophase fringe pattern from which swath bathymetry can 

be calculated. The theory,basic configuration and operational techniques for deep 

towed swath bathymetry by a fringe or isophase method will be reviewed. Examples of data will be shown and processing techniques addressed. A comparison 

with other methods will be discussed. 

Appendix 2 189 
APPENDIX 3: 

CHARTER FOR 

COORDINATION OF FEDERAL EXCLUSIVE ECONOMIC ZONE MAPPING AND 

RESEARCH PROGRAMS 

Purpose 

The Exclusive Economic Zone (EEZ) of the United States has a vast potential 

for resource development. In order to develop these resources in an 

efficient manner, it is necessary for a coordinated mapping and research 

endeavor to be formed, involving the Federal Government, State governments, private industry, and academic interests. 

The purpose of this charter is to provide a formal mechanism for the 

coordination of the Federal mapping and research activities in the EEZ of 

the United States. Coordination will avoid duplication of activities, 

assure adequate response to needs of users and provide for timely delivery of products and services and exchange of data. Coordination will also 

facilitate private sector involvement in the direction and use of 

EEZ-related data products. 

To Meet this Purpose, We Hereby Establish the U.S. Geological Survey (USGS)-National Oceanic and Atmospheric Administration (NOAA) Joint Office 

for Mapping and Research in the EEZ 

Mapping and research activities involved in the EEZ range from long-term 

ocean surveying programs, preparation of atlases and maps from new and 

existing data, and site specific research to determine the nature of the 

seafloor geology. 

Much of this research and mapping activity is conducted by the USGS in the 

Department of the Interior and by NOAA in the Department of Commerce. The 

joint USGS-NOAA office will provide natural leadership for the design, implementation, and coordination of a national EEZ program of mapping and 

research and investigation of the nonliving resources of the EEZ seafloor. 

The Joint Office will also ensure participation by all interested groups in 

the formulation of goals, objectives, and priorities for a national EEZ 

mapping and research program. 

Donald 

~~!Lw Paul Hodel 

Secretary of the Interior 

December 9, 1987 

190 Proceedings, 1991 EEZ Symposium on Mapping and Research 
APPENDIX 4: 

THE WHITE HOUSE 

Office of the Press Secretary 

Embargoed for release at 4:00pm EST March 10, 1983 

EXCLUSIVE ECONOMIC ZONE OF THE UNITED STATES OF AMERICA 

A PROCLAMATION BY THE PRESIDENT OF THE UNITED STATES OF AMERICA 

WHEREAS the Government of the United States of America desires to facilitate the wise 

development and use of the oceans consistent with international law; 

WHEREAS international law recognizes that, in a zone beyond its territory and adjacent 

to its territorial sea, known as the Exclusive Economic Zone, a coastal State may assert certain 

sovereign rights over natural resources and related jurisdiction; and 

WHEREAS the establishment of an Exclusive Economic Zone by the United States will 

advance the development of ocean resources and promote the protection of the marine environment, while not affecting other lawful uses of the zone, including the freedoms of navigation 

and overflight, by other States; 

NOW, THEREFORE, I, RONALD REAGAN, by the authority vested in me as President of the Constitution and laws of the United States of America, do hereby proclaim the 

sovereign rights and jurisdiction of the United States of America and confinn also the rights 

and freedoms of all States within an Exclusive Economic Zone, as described herein. 

The Exclusive Economic Zone of the United States is a zone contiguous to the territorial 

sea, including zones contiguous to the territorial sea of the United States, the Commonwealth 

of Puerto Rico, the Commonwealth of the Northern Mariana Islands (to the extent consistent 

with the Covenant and the United Nations Trusteeship Agreement), and United States overseas territories and possessions. The Exclusive Economic Zone extends to a distance 200 nautical miles from the baseline from which the breadth of the territorial sea is measured. In cases 

where the maritime boundary with a neighboring State remains to be determined, the boundary of the Exclusive Economic Zone shall be determined by the United States and other State 

concerned in accordance with equitable principles. 

Within the Exclusive Economic Zone, the United States has, to the extent pennitted by 

international law, (a) sovereign rights for the purpOse of exploring, exploiting, conserving and 

managing natural resources, both living and non-living, of the seabed and subsoil and the superjacent waters and with regard to other activities for the economic exploitation and exploration 

of the zone, such as the production of energy from the water, currents and winds; and (b) jurisdiction with regard to the establishment and use of artificial islands, and installations and structures having economic purposes, and the protection and preservation of the marine environment. 

The Proclamation does not change existing United States policies concerning the continental shelf, marine mammals and fisheries, including highly migratory species of tuna which are 

not subject to United States jurisdiction and require international agreements for effective 

management. 

The United States will exercise these sovereign rights and jurisdiction in accordance with 

the rules of international law. 

Without prejudice to the sovereign rights and jurisdiction of the United States, the Exclusive Economic Zone remains an area beyond the territory and territorial sea of the United 

States in which all States enjoy the high seas freedoms of navigation, overflight, and laying of 

submarine cables and pipelines, and other internationally lawful uses of the sea. 

IN WITNESS WHEREOF, I have hereunto set my hand this tenth day of March, in the 

year of our Lord nineteen hundred and eighty-three, and of the Independence of the United 

States of America the two hundred and seventh 

RONALD REAGAN 

Appendix 4 191 



SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS 

Periodicals 

Earthquakes & Volcanoes (issued bimonthly). 

Preliminary Determination of Epicenters (issued monthly). 

Technical Books and Reports 

Professional Papers are mainly comprehensive scientific reports 

of wide and lasting interest and importance to professional scientists 

and engineers. Included are reports on the results of resource studies 

and of topographic, hydrologic, and geologic investigations. They also 

include collections of related papers addressing different aspects of a 

single scientific topic. 

Bulletins contain significant data and interpretations that are of 

lasting scientific interest but are generally more limited in scope or 

geographic coverage than Professional Papers. They include the results 

of resource studies and of geologic and topographic investigations, as 

well as collections of short papers related to a specific topic. 

Water-Supply Papers are comprehensive reports that present 

significant interpretive results of hydrologic investigations of wide 

interest to professional geologists, hydrologists, and engineers. The 

series covers investigations in all phases of hydrology, including 

hydrogeology, availability of water, quality of water, and use of water. 

Circulars present administrative information or important 

scientific information of wide popular interest in a format designed for 

distribution at no cost to the public. Information is usually of short-term 

interest. 

Water-Resources Investigations Reports are papers of an 

interpretive nature made available to the public outside the formal 

USGS publications series. Copies are reproduced on request unlike 

formal USGS publications, and they are also available for public 

inspection at depositories indicated in USGS catalogs. 

Open-File Reports include unpublished manuscript reports, 

maps, and other material that are made available for public consultation 

at depositories. They are a nonpermanent form of publication that may 

be cited in other publications as sources of information. 

Maps 

Geologic Quadrangle Maps are multicolor geologic maps on 

topographic bases in 7.5- or 15-minute quadrangle formats (scales 

mainly 1:24,000 or 1:62,500) showing bedrock, surficial, or 

engineering geology. Maps generally include brief texts; some maps 

include structure and columnar sections only. 

Geophysical Investigations Maps are on topographic or planimetric bases at various scales; they show results of surveys using 

geophysical techniques, such as gravity, magnetic, seismic, or 

radioactivity, which reflect subsurface structures that are of economic 

or geologic significance. Many maps include correlations with the 

geology. 

Miscellaneous Investigations Series Maps are on planimetric or 

topographic bases of regular and irregular areas at various scales; they 

present a wide variety of format and subject matter. The series also 

includes 7 .5-minute quadrangle photogeologic maps on planimetric 

bases that show geology as interpreted from aerial photographs. Series 

also includes maps of Mars and the Moon. 

Coal Investigations Maps are geologic maps on topographic or 

planimetric bases at various scales showing bedrock or surficial 

geology, stratigraphy, and structural relations in certain coal-resource 

areas. 

Oil and Gas Investigations Charts show stratigraphic 

information for certain oil and gas fields and other areas having 

petroleum potential. 

Miscellaneous Field Studies Maps are multicolor or black-andwhite maps on topographic or planimetric bases for quadrangle or 

irregular areas at various scales. Pre-1971 maps show bedrock geology 

in relation to specific mining or mineral-deposit problems; post-1971 

maps are primarily black-and-white maps on various subjects such as 

environmental studies or wilderness mineral investigations. 

Hydrologic Investigations Atlases are multicolored or blackand-white maps on topographic or planimetric bases presenting a wide 

range of geohydrologic data of both regular and irregular areas; 

principal scale is 1:24,000, and regional studies are at 1:250,000 scale 

or smaller. 

Catalogs 

Permanent catalogs, as well as some others, giving 

comprehensive listings of U.S. Geological Survey publications are 

available under the conditions indicated below from the U.S. 

Geological Survey, Book and Open-File Report Sales, Federal Center, 

Box 25425, Denver, CO 80225. (See latest Price and Availability List.) 

"Publications of the Geological Survey, 1879-1961" may be 

purchased by mail and over the counter in paperback book form and as 

a set of microfiche. 

"Publications of the Geological Survey, 1962-1970" may be 

purchased by mail and over the counter in paperback book form and as 

a set of microfiche. 

"Publications of the U.S. Geological Survey, 1971-1981" may 

be purchased by mail and over the counter in paperback book form (two 

volumes, publications listing and index) and as a set of microfiche. 

Supplements for 1982, 1983, 1984, 1985, 1986, and for 

subsequent years since the last permanent catalog may be purchased by 

mail and over the counter in paperback book form. 

State catalogs, "List of U.S. Geological Survey Geologic and 

Water-Supply Reports and Maps For (State)," may be purchased by 

mail and over the counter in paperback booklet form only. 

"Price and Availability List of U.S. Geological Survey 

Publications," issued annually, is available free of charge in paperback 

booklet form only. 

Selected copies of a monthly catalog "New Publications of the 

U.S. Geological Survey" are available free of charge by mail or may 

be obtained over the counter in paperback booklet form only. Those 

wishing a free subscription to the monthly catalog "New Publications of 

the U.S. Geological Survey" should write to the U.S. Geological 

Survey, 582 National Center, Reston, VA 22092. 

Note.-Prices of Government publications listed in older 

catalogs, announcements, and publications may be incorrect. 

Therefore, the prices charged may differ from the prices in catalogs, 

announcements, and publications.