U.S. Geological Survey

Coastal and Marine Geology Research—

Recent Highlights and Achievements

U.S. GEOLOGICAL SURVEY CIRCULAR 1199

U.S. Department of the Interior

U.S. Geological Survey
Cover: Perspective map of Massachusetts Bay and Cape Cod Bay showing the complex

underwater topography. From U.S. Geological Survey Fact Sheet FS–172–97. The discharge of treated sewage effluent from the Boston metropolitan area is being relocated

from Boston Harbor to a new site 15 kilometers offshore in Massachusetts Bay. Detailed

geologic maps and circulation modeling provided by the USGS were used in selecting

the new outfall location; see p. 7.
U.S. Department of the Interior

U.S. Geological Survey

U.S. Geological Survey

Coastal and Marine Geology Research—

Recent Highlights and Achievements

By S. Jeffress Williams, Peter Barnes, and Ellen J. Prager

U.S. GEOLOGICAL SURVEY CIRCULAR 1199
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

CHARLES G. GROAT, Director

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 2000

Published in the Eastern Region, Reston, Va.

Manuscript approved for publication May 24, 2000.

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.

Free on application to

U.S. Geological Survey

Information Services

Box 25286, Federal Center

Denver, CO 80225

or call the toll-free telephone number

1–888–ASK–USGS

Library of Congress Cataloging in Publication Number

00–044263
PREFACE

To ensure that the U.S. Geological Survey (USGS) is prepared to meet society’s

need for scientific information, the USGS has developed a scientific strategy to address

the complex earth science issues that the Nation and the world are likely to face in the

next decade. As part of that strategy, the USGS Coastal and Marine Geology Program

has large-scale national and regional research projects that focus specifically on environmental quality, geologic hazards, natural resources, and information transfer. These

themes parallel and complement the goals of the USGS science strategy.

This Circular highlights recent scientific findings, products, and activities of the

USGS Coastal and Marine Geology Program. Research results as highlighted here play

a vital role in the USGS endeavor to understand human interactions with the natural

environment and to determine how the fundamental geologic processes controlling the

Earth work. The scientific knowledge acquired through USGS research, assessment, and

monitoring is critically needed by planners, government agencies, and the public.

Effective communication of the results of this research will enable the USGS Coastal

and Marine Geology Program to play an integral part in assisting the Nation in responding to the pressing earth science challenges of the 21st century. 

The list on the next page hints at the variety of recent activities described in this

Circular. 

S. Jeffress Williams, Coordinator

Coastal and Marine Geology Program

Peter Barnes, former Associate Coordinator

Coastal and Marine Geology Program

III
Scientists from the U.S. Geological Survey’s Coastal and

Marine Geology Program–

• studied El Niño-induced storm erosion and landslides along California’s coast. The USGS is providing information that will help prevent loss of land

and property during future El Niño events.

• went to Papua New Guinea in the wake of one of

the most devastating tsunamis ever (top figure) to

learn how and why the tsunami occurred so that, in

the future, coastal communities worldwide can be

warned of and better prepared for tsunamis.

• developed a low-cost, easily deployed, and highly

accurate research system, called SWASH (middle

figure), to measure and monitor beach erosion and

long-term change and to rapidly assess storm

impacts on the shoreline.

• completed scientific mapping of the sea floor, sediments, and biologic habitat in areas such as

Massachusetts Bay, Stellwagen Bank Marine

Sanctuary, Monterey Bay Marine Sanctuary, Long

Island Sound, and San Francisco Bay (bottom figure). These maps enable local, State, and Federal

managers to make informed decisions about waste

disposal, marine reserves, resource use and conservation, navigation hazards, and dredging operations.

• led the scientific field in the study of coral reefs in

Hawaii and the Florida Keys, gas hydrates, and

ground-water flow and developed a multi-agency

hurricane response team to study storm impacts in

coastal environments.

Access to general information about the USGS can 

be obtained through the World Wide Web at http://

www.usgs.gov. More detailed information on projects,

data, maps, and other products by the Coastal and Marine

Geology Program is referenced throughout this Circular or

can be found at http://marine.usgs.gov.

Damage from the tsunami that hit Papua New

Guinea on July 17, 1998. Computer modeling

by the USGS may help predict future

tsunamis. See p. 18.

The SWASH (Surveying Wide Area of

Shorelines) system, developed by the USGS

for accurate measurements of shoreline position using recent advances in the Global

Positioning System (GPS). See p. 15.

Multibeam map of the underwater topography

of west-central San Francisco Bay merged

with a Landsat image. The map was prepared

by the USGS and its partners to help understand sea-floor processes and find safe disposal sites for dredge materials. See p. 10.

IV
CONTENTS

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .III

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Coastal and Marine Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Program Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Cooperators, Partners, and Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Facilities and Research Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Information Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Program Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Environmental Quality and Preservation Theme . . . . . . . . . . . . . . . . . .7

Urban Estuaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Massachusetts Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

New York-New Jersey Region . . . . . . . . . . . . . . . . . . . . . .7

Long Island Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Chesapeake Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Sea-Level Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Impact Crater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Lake Pontchartrain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Southern California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

San Francisco Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Fragile Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Louisiana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Florida . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Coral Reefs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Critical Habitats and National Marine Sanctuaries . . . . . . . . . . .12

Monterey Bay, California . . . . . . . . . . . . . . . . . . . . . . . . .13

Florida Keys and Oculina Bank Off Florida . . . . . . . . . . .13

Georges Bank Off Massachusetts . . . . . . . . . . . . . . . . . . .13

Stellwagen Bank Off Massachusetts . . . . . . . . . . . . . . . . .13

Natural Hazards and Public Safety Theme . . . . . . . . . . . . . . . . . . . . . .15

Coastal Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

SWASH: Surveying Wide Area of Shorelines . . . . . . . . . .15

Southwest Washington . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Louisiana Barrier Islands . . . . . . . . . . . . . . . . . . . . . . . . .16

South Carolina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Hurricanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

El Niño . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Tsunamis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Landslides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Earthquakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Natural Resources Theme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Methane Gas Hydrates . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Gulf of Mexico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Marine Sand and Gravel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Southern Long Island . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Florida . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Program Highlights—Continued

Information and Technology Theme . . . . . . . . . . . . . . . . . . . . . . . . . .21

Sea-Floor Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

GLORIA Imagery of the U.S. Exclusive Economic Zone .21

Other Sea-Floor Mapping . . . . . . . . . . . . . . . . . . . . . . . . .21

Airborne Laser Mapping (LIDAR) . . . . . . . . . . . . . . . . . . . . . . .22

Computer Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Remote Sensing of the Coastal Ocean . . . . . . . . . . . . . . . . . . . .23

Developing and Testing New Technologies . . . . . . . . . . . . . . . .23

Ocean Bottom Seismometer (OBS) . . . . . . . . . . . . . . . . . .23

Gas Hydrate And Sediment Test Laboratory 

Instrument (GHASTLI) . . . . . . . . . . . . . . . . . . . . . . . .24

Information Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Future Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Coral Reefs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Mapping of Sea-Floor Habitats . . . . . . . . . . . . . . . . . . . . . . . . .25

Understanding Coastal and Inner Shelf Systems . . . . . . . . . . . . . .25

Storm Impacts in the Coastal Zone . . . . . . . . . . . . . . . . . . . . . .25

Relative Sea-Level Rise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Methane Gas Hydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Geologic Controls on Ground-Water Resources . . . . . . . . . . . . . . .26

Deepwater Gulf of Mexico . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Regional Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

FIGURES

1. Photograph of dense population and development along a barrier island in the Florida Gulf Coast area . . .3

2. Map showing locations of the headquarters and three centers for the USGS Coastal and Marine 

Geology Program and areas where most program research is carried out . . . . . . . . . . . . . . . . . . . . . . . . . .4

3. Perspective map of Massachusetts Bay and Cape Cod Bay showing the complex underwater topography .7

4. Maps showing model comparison of winter near-surface effluent concentrations at the existing and new 

sewage outfall sites in Massachusetts Bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

5. Reconnaissance map showing the distribution of sedimentary environments across the Long Island 

Sound estuary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

6. Cross section showing the main features of the Chesapeake Bay impact crater . . . . . . . . . . . . . . . . . . . . . .9

7. Map showing the location of the Chesapeake Bay bolide impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

8. Map showing grain-size distribution in the bottom sediments of Lake Pontchartrain . . . . . . . . . . . . . . . . .10

9. Multibeam map showing underwater topography of west-central San Francisco Bay combined with a 

Landsat image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

10. Air photograph of canals dredged in Louisiana’s wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

11. Image of the Atchafalaya River Delta of Louisiana showing accretion and wetland development . . . . . . .11

12. Photograph showing black-band disease on a brain coral on a reef at Rum Cay in the eastern Bahamas . .12

13. Photograph of a sandy barrier island . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

14. Photographs of benthic habitats on Georges Bank showing a natural, undisturbed habitat and a region 

disturbed by fishing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

15. Geomorphologic map of Stellwagen Bank National Marine Sanctuary mapped by a multibeam echo 

sounder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

VI CONTENTS
CONVERSION FACTORS

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch

meter (m) 3.281 foot

kilometer (km) 0.6214 mile

nautical mile 1.852 kilometer

Area

hectare (ha) 2.471 acre

square kilometer (km2) 0.3861 square mile

16. Photograph of the SWASH vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

17. Map showing historical erosion at Cape Shoalwater, Washington, from 1887 to 1995 . . . . . . . . . . . . . . .15

18. Maps showing dramatic changes in the Isles Dernieres barrier islands along the Louisiana coast from 

1853 to 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

19. Photographs of Topsail Island, North Carolina, before and after Hurricane Fran, showing the dramatic 

effects of storm surge overwash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

20. Photographs of the California coast in early 1998 before and after a series of El Niño winter storms 

caused severe beach erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

21. Photographs of the mouth of Tomales Bay at Point Reyes National Seashore, California, before and 

after El Niño storms greatly enlarged the beach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

22. Photograph of damage caused by the tsunamis that hit Papua New Guinea on July 17, 1998 . . . . . . . . . .18

23. One frame of a USGS computer simulation of the tsunamis that hit Papua New Guinea on July 17, 1998 . .18

24. Seismic profile of the sea floor off South Carolina. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

25. Map of offshore sand resources south of Long Island that may be used for beach replenishment. . . . . . . .20

26. Perspective view of the sea floor off western Florida based on GLORIA sidescan-sonar imagery from 

the USGS and bathymetry from NOAA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

27. Perspective view looking northeast from the Pacific Ocean toward Los Angeles and Palos Verdes . . . . . .22

28. Diagram of NASA’s airborne laser mapper (LIDAR) system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

29. Map of tidal flushing of Boston Harbor based on computer simulations . . . . . . . . . . . . . . . . . . . . . . . . . .24

30. Satellite images of Florida Bay showing sea-surface temperature and reflectance . . . . . . . . . . . . . . . . . . .24

31. Photograph of the Ocean Bottom Seismometer, which was developed by the USGS to acquire seismic 

data on the sea floor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

32. Photograph of part of the GHASTLI system built by the USGS to study gas hydrates . . . . . . . . . . . . . . .24

TABLE

1. Sea-floor images by the USGS Coastal and Marine Geology Program and cooperators . . . . . . . . . . . . . .22

CONTENTS VII
INTRODUCTION
COASTAL AND MARINE ISSUES

The U.S. Geological Survey is the Nation’s premier

earth science agency, responsible for providing credible,

objective, and significant scientific information to improve

and protect the quality of life on Earth and contribute to a

future of wise economic development, sustainable resource

use, and environmental preservation. Within the Coastal

and Marine Geology Program, the USGS focuses its

efforts on issues the Nation faces in coastal and marine

environments, including the Great Lakes.

Today, more than half of all Americans live within an

hour’s drive of the coast; by the year 2010, this is expected

to increase to an astounding 75 percent. In addition, one

out of every six jobs in America is related to or associated

with the marine environment. As human populations increase,

particularly within the coastal zone (fig. 1), so do their

impact, resource needs, and vulnerability to natural hazards.

Pollution within coastal bays, particularly in areas of

urban development, has already threatened human health,

damaged fragile environments, hurt the fishing industry,

and curtailed recreational activities. Wetlands, coral reefs,

and mangroves play a vital role in the coastal ecosystem,

but they are vulnerable habitats. Louisiana is losing as

much as 75 square kilometers of its wetlands each year

due to both natural and human-induced change. Coral

reefs, which some consider the “canary of the seas,” are

showing signs of global decline and may signal an overall

trend towards ocean degradation. 

Figure 1. Dense populations and development along barrier islands like the Florida Gulf Coast area shown here are

vulnerable to hazards from coastal erosion, storms, and

sea-level rise. USGS photograph.

Although demand is steadily increasing, supplies of

drinking water, sand for construction and beach replenishment, and energy resources are all in decline. Denser populations along the shore leave more communities vulnerable

to hazards from coastal erosion, catastrophic storms, landslides, and tsunamis. In Hawaii, nearly 30 km of Oahu’s

beaches have been lost due to erosion over the last century.

In 1997 and 1998, El Niño-related storms and major hurricanes, such as Georges and Mitch, caused enormous loss of

life and billions of dollars in damage within the coastal zone.

PROGRAM RESEARCH

This Circular contains highlights of USGS Coastal and

Marine Geology Program research organized under the following themes of national importance:

• Environmental quality and preservation

• Natural hazards and public safety

• Natural resources

• Information and technology

A final section summarizes future research needs.

COOPERATORS, PARTNERS,

AND CLIENTS

The USGS is committed to providing other Federal

and State agencies, industry, the public, and the scientific

community with the most relevant, credible, and objective

scientific information possible. To best utilize the expertise

and technology available today, the USGS works with

other government agencies, industry, academia, and organizations to form cooperative partnerships in earth science

research and technology development. The highlights

include the names of many cooperators. 

FACILITIES AND RESEARCH AREAS

The 250 scientists and support staff of the USGS

Coastal and Marine Geology Program work at three regional centers: Menlo Park, Calif.; St. Petersburg, Fla., and

Woods Hole, Mass. Facilities are co-located with other

Federal and academic institutions to facilitate cooperation

and to share expertise and resources. Figure 2 shows the

U.S. Geological Survey

Coastal and Marine Geology Research—

Recent Highlights and Achievements

3
4 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

Lisa Robbins

USGS

600 Fourth Street South

St. Petersburg, FL 33701

Telephone: (727) 803–8747 x3002

Web site: http://coastal.er.usgs.gov

Michael D. Carr

USGS, Mail Stop 999

345 Middlefield Road

Menlo Park, CA 94025

Telephone: (650) 329–5011

Web site: http://walrus.wr.usgs.gov

S. Jeffress Williams, Coordinator

Coastal and Marine Geology Program

USGS 

915-B National Center

Reston, VA 20192

Telephone: (703) 648–6511

Web site: http://marine.usgs.gov

John W. Haines, Associate Coordinator

Coastal and Marine Geology Program

USGS 

915-B National Center

Reston, VA 20192

Telephone: (703) 648–6422

Web site: http://marine.usgs.gov

locations of the three centers and areas where most

program research is carried out.

Although the program’s primary focus is on

coastal, estuary, and continental shelf regions, studies

encompass the Great Lakes and offshore deep-ocean

areas within the U.S. Exclusive Economic Zone

(EEZ). The EEZ was created on March 10, 1983,

when President Reagan declared an expansion of the

United States’ sovereign rights to all natural resources

within a zone extending to 200 nautical miles beyond

the shoreline. The proclamation provided a mandate

for exploration and resource utilization. The program

has also done research in some international areas,

which provide opportunities to understand fundamental marine and coastal geology.

INFORMATION SOURCES

Access to general information about the USGS

can be obtained through the World Wide Web at

http://www.usgs.gov. More detailed information on

projects, data, maps, and other products by the Coastal

and Marine Geology Program is referenced throughout

this Circular or can be found at http://marine.usgs.gov.

For additional information about projects and

products described in this Circular, contact one of the

people listed below.

Deborah Hutchinson

USGS

384 Woods Hole Road

Woods Hole, MA 02543

Telephone: (508) 457–2211

Web site: http://woodshole.er.usgs.gov

Figure 2. Locations of the headquarters in Reston, VA, and the three centers for the USGS Coastal and Marine Geology Program and

areas where most program research is carried out.
PROGRAM HIGHLIGHTS
Environmental Quality and Preservation Theme

7

Boston Harbor will be greatly reduced without significantly increasing concentrations in Massachusetts Bay. Figure

4 shows a model comparison of winter near-surface effluent concentrations at the existing and new outfall sites.

USGS collaborators and clients in the Massachusetts

Bay Study include the U.S. EPA, the National Oceanic and

Atmospheric Administration (NOAA), the Massachusetts

Environmental Trust, the Massachusetts Water Resources

Authority, the U.S. Coast Guard, and Woods Hole

Oceanographic Institution. A CD-ROM (compact disc,

read-only memory) containing the Massachusetts Bay seafloor map is available as USGS Digital Data Series DDS–3

(Bothner and others, 1992).

NEW YORK–NEW JERSEY REGION 

The USGS and its partners have mapped (1) the sea

floor along the southern shore of Long Island and off New

The goal of research under the theme of environmental

quality and preservation is to aid in the preservation of

coastal and marine habitat, enable long-term sustainable

resource use while maintaining environmental quality, and

anticipate possible environmental impacts of climate

change. The USGS Coastal and Marine Geology Program

is providing critical information about the sea floor, sediments, ocean currents, habitat distribution, contamination,

sea-level rise, and geologic history in areas including urban

estuaries, fragile environments, such as wetlands and coral

reefs, and marine reserves and other important biologic

habitats.

URBAN ESTUARIES 

Coastal bays within highly developed and populated

regions provide invaluable resources but face mounting

environmental pressures. Coastal managers, policymakers,

and commercial and recreational users need information

about the sea floor, sediments, ocean currents and waves,

and circulation in urban estuaries to address problems associated with dredging, waste disposal, resource assessment,

rising sea level, navigation hazards, and the preservation of

important biologic habitats. Results of recent and ongoing

Coastal and Marine Geology Program research in urban

estuaries demonstrate the practical applicability and societal need for earth science information.

MASSACHUSETTS BAY

The discharge of treated sewage effluent from the

Boston metropolitan area is being relocated from Boston

Harbor to a new site 15 km offshore in Massachusetts Bay

(fig. 3). Detailed geologic maps and circulation modeling

provided by the USGS were used in selecting the new outfall location.

On the basis of USGS mapping of sediment type, two

regions close to the new disposal site were identified as

areas sensitive to change and potential contamination. Two

long-term stations were established in these areas to monitor environmental change. Figure 3 shows the complex

underwater topography of the region and the new outfall

location.

USGS scientists simulated circulation in Boston

Harbor and Massachusetts Bay based on wind, river runoff,

offshore discharges, surface temperature, tides, and sealevel fluctuations. Model results suggest that with the relocation of the sewage outfall, effluent concentrations in

Figure 3. Perspective map of Massachusetts Bay and Cape Cod

Bay showing the complex underwater topography and the new

outfall location east of the Deer Island treatment plant (red dot).

From Butman and others (1998). MBDS, Massachusetts Bay

disposal site, which receives material dredged from the harbors

of Boston and nearby cities.
8 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

Figure 5. Reconnaissance map showing the distribution of sedimentary environments across the

Long Island Sound estuary. Sedimentary environments have been inferred from sonograph patterns,

sediment samples, video-camera observations, and

modeled current and wave data. The 10-meter

depth contour delineates the shoreward limit of the

study area along the Connecticut and Long Island

coasts. From Knebel (1998).

York City by using sidescan sonar and (2) the undersea

Hudson Shelf valley and adjacent shelf off New Jersey by

using multibeam surveys. These remotely sensed data

were combined with high-resolution seismic-reflection

profiles, sediment samples, and visual observations to

characterize the sea floor, to study sediment transport, to

define biological habitats, and to locate areas affected by

human activities. Partners include the U.S. Army Corps of

Engineers, Texas A&M University, the State University of

New York at Stony Brook, the University of New

Brunswick, the Canadian Hydrographic Service, Wesleyan

University (Connecticut), and Coastal Carolina University.

LONG ISLAND SOUND

The USGS, in cooperation with the Connecticut

Department of Environmental Protection and the U.S.

EPA, has mapped the distribution of bottom sediments in

Long Island Sound (fig. 5). This information provides

managers insight into the long-term fate of contaminants

that are associated with fine-grained materials, areas of

erosion versus deposition, potential sites for disposal of

dredge spoil, and regional sand and gravel resources.

Additional studies within the region are being conducted in collaboration with the U.S. Army Corps of

Engineers, the Canadian Hydrographic Service, and 

Figure 4. Model comparison of winter near-surface

effluent concentrations at the existing and new sewage

outfall sites in Massachusetts Bay. From Signell (1998).

The red line indicates a concentration of 0.5 percent (200-

fold dilution of effluent), which is approximately the

level at which nutrient levels released in the effluent are

comparable to background variability. With the existing

outfall locations, high effluent concentrations are found

within Boston Harbor and along the coastline immediately south. With the new outfall location, high concentrations are found only within a few kilometers of the outfall, concentrations are dramatically lower in Boston

Harbor, and concentrations in most of Massachusetts Bay

(including the region near Stellwagen Bank) are not significantly changed from their existing low levels. The

white outline indicates the location of Stellwagen Bank.
ENVIRONMENTAL QUALITY AND PRESERVATION THEME 9

several universities to examine the geologic controls on

shoreline erosion, to identify areas of recent and past dredge

spoil disposal, and to assess sediment transport patterns.

CHESAPEAKE BAY

The USGS is working with Federal, State, and academic partners to understand the complex geologic and sealevel history within the Chesapeake Bay. Results so far

have proven surprising and have important implications

for coastal zone management and resource use in the region.

SEA-LEVEL CHANGES

The USGS role in sea-level research is national in

scope and ranges from remote sensing and geologic mapping of wetlands to studies of coastal erosion and evidence

of older shorelines in the geologic record. Both short- and

long-term environmental records are taken into account.

One goal is to be able to determine the rate of sea-level

change on century to millennium time scales in order to

compare consistency and agreement (or lack thereof) with

the decadal and annual records of the tide gages. 

In the Chesapeake Bay, the USGS is conducting

research to reconstruct the detailed pattern of relative sealevel change during the last 6,000 to 8,000 years. Few

modern data are available from which to establish baselines to compare with the ongoing rate of sea-level rise.

Current research efforts focus on the central region of the

Chesapeake Bay. For example, coring studies of marshes

and tributary creeks in the Patuxent River basin are providing sedimentary and biological records of rising sea

level.

Scientists at the USGS are also developing a detailed

record of relative sea-level rise within the Chesapeake Bay

area to assist local, State, and regional managers in assessing the potential for flooding and coastal erosion.

IMPACT CRATER

A massive impact crater has been identified beneath

the southern part of Chesapeake Bay about 200 km southeast of Washington D.C. (figs. 6, 7). Evidence of the crater

comes from two main sources of data on the rock and sediment structure: (1) seismic-reflection profiles collected by

Texaco, Inc., the USGS, and the National Geographic

Society and (2) sediment cores drilled by the USGS and

the Virginia State Water Control Board. The impact crater

was created by a comet or asteroid (bolide), some 3 to 5

km across, that struck the Earth approximately 35 million

years ago. 

Study of the giant crater beneath Chesapeake Bay

indicates that breccia within the crater compacted more

under subsequent sediment layers than did partially 

Figure 7. Location of Chesapeake Bay bolide

impact relative to modern cities and the ancient

shoreline when the bolide hit. From Poag (1998).

Figure 6. Cross section showing main features of the Chesapeake Bay impact crater. From Poag (1998).
10 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

Figure 8. Grain-size distribution in the bottom sediments of Lake Pontchartrain. Color reflects percent sand,

with lighter colors indicating a higher sand content. From Manheim (1999).

consolidated deposits surrounding the crater. Crater-related

ground subsidence created faults beneath the bay floor,

and it may have increased the rate of relative sea-level rise

in the region. Furthermore, the crater may have diverted

river flow, and it greatly modified all ground-water

aquifers in the area. Data suggest that extraordinarily salty

water is trapped beneath freshwater resources; thus, care

should be taken not to inadvertently drill into lower layers

and contaminate the overlying aquifer. The crater investigation also indicates that ground-water use on the

Delmarva Peninsula must be especially conservative.

More information on this project can be obtained from the

Woods Hole Center (p. 4) or the web site at 

http://woodshole.er.usgs.gov/epubs/bolide/.

LAKE PONTCHARTRAIN

USGS scientists are studying sediment and groundwater contamination, transport processes, and coastal erosion in Louisiana’s largest estuary, Lake Pontchartrain.

The map of grain-size distribution shown in figure 8 is an

example of the results that are being incorporated into an

atlas for the area. Studies show that metals tend to accumulate in fine-grained sediments. Research is also being

conducted to examine the effects of major discharges, to

model lake circulation, to assess the chemical nature and

history of the lake bed, and to determine the stability of

the local shoreline and associated wetlands. The USGS is

working extensively with local partners, including

Louisiana’s Departments of Natural Resources and

Fisheries and Wildlife, the University of New Orleans,

Tulane University, the U.S. EPA, the U.S. Army Corps of

Engineers, and the Lake Pontchartrain Basin Foundation.

This project has received extensive media coverage and is 

providing critical information to coastal zone managers,

policymakers, commercial interests, recreational users, and

local communities in Louisiana.

SOUTHERN CALIFORNIA

Recent surveys by the USGS have shown that in

Santa Monica Bay, west of Los Angeles, contamination of

over 95 percent of the bay has reached levels that will

affect biological processes. In collaboration with the city

of Los Angeles and the Southern California Coastal Water

Research Project, the USGS is conducting research to

determine the severity of present contamination levels in

the sediments and changes that have occurred over time.

Analysis of sediment samples representing the last 100

years suggests that contamination levels were worse in the

past and that, overall, conditions are improving. Continued

monitoring is planned, and a study of the processes controlling sediment transport in the bay is underway.

SAN FRANCISCO BAY

San Francisco Bay is the largest estuary on the U.S.

West Coast and is the site of an extensive USGS program.

Scientists are working with numerous partners to provide

maps of the sea floor and sediments, to model sediment

transport pathways and circulation, to assess historical

change and geologic structure, and to monitor nearby wetlands. Figure 9 combines a map of underwater topography

in San Francisco Bay with a satellite image; the map is

being used to assess hazards to navigation and to locate

sites for the safe disposal of dredge materials. Using stateof-the-art instrumentation and communications equipment,

the USGS and its partners provide the local community,
ENVIRONMENTAL QUALITY AND PRESERVATION THEME 11

researchers, and managers access to real-time information

on water levels, currents, salinity, and winds within the bay.

The USGS has recently released a set of maps and

interpretations to regional officials and the public for

assessing the potential for landslides and debris flows in

the area under future El Niño climate conditions. The

maps are available on the web at http://wrgis.wr.usgs.gov/

open-file/of97-745/.

HAWAII

In the early 1990’s, the USGS began working with the

U.S. Army Corps of Engineers and the U.S. EPA to study

dredge spoil disposal in Mamala Bay off Oahu, Hawaii.

Previous sites of dredge material dumping have been identified, and results suggest that currents are probably shifting sea-floor sediments and dredge spoil. Further work is

being conducted to assess the impact of dredged materials

on local habitats and to determine if dredged materials are

being moved toward coral reef areas. More information is

available on the web at http://walrus.wr.usgs.gov/

mamalabay/.

FRAGILE ENVIRONMENTS

Many areas of the U.S coastline and island territories in the Caribbean and Pacific are lined with highly

productive, yet fragile salt marshes, cypress swamps,

mangroves, and coral reefs. These coastal environments harbor diverse and abundant wildlife, are critical nursery grounds for numerous commercial fish and

shellfish species, provide protection from storms, and

supply coastal communities with economic resources.

Unfortunately, wetlands and coral reefs are highly vulnerable to the impacts of human activities and natural

change. To help preserve these critical environments,

the USGS is working to improve our scientific understanding of how natural processes and human influences

shape and modify wetlands and coral reef environments.

WETLANDS

LOUISIANA

Louisiana’s 3 million hectares of wetlands are being

lost at alarming rates, some 7,500 hectares (75 square kilometers) per year. Along with its Federal, State, and university partners, the USGS has found that a complex combination of natural and human factors contributes to the

demise of Louisiana’s wetlands. Sea-level rise, storms,

sediment starvation, and land subsidence are the main

agents of natural wetland loss.

Louisiana’s fragile wetlands have been damaged,

directly and indirectly, by canals dredged over the past

100 years for navigation and energy exploration (fig. 10).

Seasonal flooding that once brought much-needed sediments into the wetlands of the Mississippi River and

Atchafalaya River Deltas (fig. 11) and other areas has

Figure 9. Multibeam map showing underwater topography

of west-central San Francisco Bay combined with a Landsat

image. From http://terraweb.wr.usgs.gov/TRS/projects/

SFBaySonar/main30.html.

Figure 11. Image of the Atchafalaya

River Delta of Louisiana showing

accretion and wetland development

that have occurred since floods in

the early 1970’s.

Figure 10. Air photograph of canals dredged in

Louisiana’s wetlands for navigation and energy development; these canals have accelerated wetland loss over the

past 50 years. USGS photograph taken in about 1985. 
12 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

Figure 12. Black-band disease on a

brain coral on a reef at Rum Cay in the

eastern Bahamas in 1990. This and other

types of band diseases can destroy a 200-

year-old head in a single summer. From

Lidz (1997).

been greatly reduced by levee construction, dams, and

rerouted discharges. Canals also allow saltwater from the

Gulf of Mexico to flow into once brackish or freshwater

wetlands, killing the vegetation. Wetland drainage for

development and agricultural purposes is another contributor to wetland loss.

The USGS is working with its Federal and State partners to develop cost-effective methods to mitigate wetland

loss and restore the coast. Data on sea-level rise, subsidence, sediment transport, storms, and ocean currents are

being used to model future diversions or alterations of the

Mississippi River and to assist in other possible solutions,

including sediment renourishment (a means to introduce

sediment into the wetlands) and the restoration of coastal

barrier islands.

FLORIDA

In Florida, USGS scientists are using satellite images

to map and understand wetland change. The use of satellite imagery allows scientists and local officials to examine large regions and identify specific problem areas.

Scientists can then closely monitor the geologic and physical processes that may be causing wetland loss in problem

areas.

CALIFORNIA

Loss of wetlands is also a major problem on the U.S.

West Coast. USGS scientists, working in cooperation with

Federal and State agencies, have initiated a long-term

study and monitoring of the wetlands within the San

Francisco Bay area. Of particular interest in this region is

the need for sites suitable for the disposal of dredge material. Researchers studied the Sonoma Baylands as a demonstration site; the results suggest that dredge spoil from the

Petaluma River contributes only trace levels of contaminants to the wetlands. In a sample taken outside the

demonstration dump site, researchers measured significant

levels of the pesticide DDT and hydrocarbons; however,

they suspect that a nearby agricultural pump and drain are

the sources of contamination.

CORAL REEFS

The USGS, in cooperation with the University of

South Florida, recently published new maps of the reef

and sediment distribution and thickness for a major portion of Florida’s coral reef tract (Lidz and others, 1997).

Throughout the reef tract, corals are generally perceived as

declining and may be vulnerable to diseases like that

shown in figure 12. These maps are providing scientists,

policymakers, and local community leaders with important

information for coral reef management and understanding.

Results of another USGS project in South Florida

suggest that the amount of coral fragments in the sand surrounding Florida’s reefs can be used as a measure of reef

vitality and possibly of regional coral health. Scientists

studying sewage disposal and ground-water movement

beneath the Florida Keys found that offshore reefs are

probably not affected by sewage-contaminated ground

water; however, nearshore environments are threatened by

polluted discharges.

In nearby Florida Bay, studies of sediment cores and

the geochemistry of mollusk shells indicate that major

changes in salinity and productivity have occurred during

the past two centuries. USGS research suggests that past

efforts to drain the Everglades and reduced freshwater

inflow are related to these changes in the bay. These measurements are providing engineers and managers with crucial information as they attempt a multi-billion-dollar

effort to restore the Everglades and Florida Bay ecosystem.

In Puerto Rico, USGS scientists are studying the

recovery of reefs following hurricane damage. Sheltered

reefs were found to be little affected, while exposed reefs

recovered from one storm only to be damaged by two

more hurricanes. Monitoring in Puerto Rico continues in

an attempt to better understand the long-term impacts of

hurricanes on coral reefs.

In Hawaii, USGS scientists are examining how reefs

alter incoming waves and influence sediment transport and

beach erosion. In 1998, the USGS held a coral reef workshop in Hawaii and brought together eminent scientists

from around the world to discuss the most crucial issues in

coral reef research today.

CRITICAL HABITATS AND NATIONAL

MARINE SANCTUARIES

The USGS recognizes the importance of preserving

special coastal and marine areas that are of critical biologi-
ENVIRONMENTAL QUALITY AND PRESERVATION THEME 13

cal significance and offer unique economic and recreational values (fig. 13). Therefore, a USGS priority is to

provide information to managers, policymakers, and the

public about National Marine Sanctuaries and other essential habitats. The following projects represent the beginning of an ongoing effort to help preserve our Nation’s

critical coastal and marine environments.

MONTEREY BAY, CALIFORNIA

In Monterey Bay National Marine Sanctuary,

California, the USGS and its Federal, State, and local

partners are mapping the sea-floor topography and the distribution of sediments and biologic habitats. Researchers

study how sediments are eroded, deposited, and transported through the sanctuary; this information will help managers to protect habitats in the marine sanctuary.

FLORIDA KEYS AND OCULINA BANK 

OFF FLORIDA

Numerous USGS projects are underway in the Florida

Keys National Marine Sanctuary and nearby Florida Bay

(see previous section on “Fragile Environments”). Plans

are also being made to map coral reefs in the Keys and

assess their growth, health, and prospects for future survival. In conjunction with NOAA’s National Marine

Fisheries Service (NMFS), the USGS has surveyed a

deepwater coral reef habitat off Florida’s east coast.

Recognized as an area of special significance by the South

Atlantic Fishery Management Council, Oculina Bank has

been mapped, and areas of former and current coral

growth have been identified (Scanlon and others, 1999).

USGS scientists are studying coral transplants within the

area as a means to restore damaged reef habitats.

GEORGES BANK OFF MASSACHUSETTS

A joint project by the USGS and the NMFS is documenting the interaction between physical/geological factors and fishery abundance and distribution on Georges

Bank off Massachusetts. USGS maps show that historic

fish-spawning grounds on the eastern portion of the bank

are located on the gravel sea floor where the strongest

tidal currents occur between sand ridges (Valentine and

Lough, 1991; Lough and others, 1992; Valentine and others, 1992, 1993). Data suggest that the physical disturbance of the sea floor by tides, storms, and commercial

fishing activities alters benthic habitats. Figure 14 shows

natural and disturbed benthic habitats on Georges Bank.

STELLWAGEN BANK OFF MASSACHUSETTS

The USGS is producing a series of maps that includes

a general overview, the bottom topography, and sediment

Figure 13. Sandy barrier islands provide a buffer for

waves and flooding and important habitats for marine

life. USGS photograph.

Figure 14. Benthic habitats on Georges

Bank: above, a natural, undisturbed habitat;

below, a region disturbed by fishing activities. USGS photographs.
and biologic habitat distribution in the Stellwagen Bank

National Marine Sanctuary off Massachusetts (fig. 15).

These maps and data are a basis for policymakers, managers, and other scientists to understand this complex

ecosystem and wisely manage its economic and natural

assets. This project is being done in collaboration with

NOAA, the U.S. EPA, the Canadian Hydrographic

Service, and the University of New Brunswick (Valentine

and others, 2000).

14 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

Figure 15. Geomorphology of Stellwagen Bank National Marine Sanctuary (red polygon) mapped

by a multibeam echo sounder on four cruises, 1994 to 1996. From Valentine and Butman (1998) and

Valentine and others (2000). The geomorphology is shown on a map with backscatter intensity

draped over the topography and with shadows added as if the sun were shining. Red indicates highbackscatter material including coarse sand, gravel, and rock; green indicates sand; blue indicates

mud. Within each backscatter color interval, the intensity varies from dark to light depending on the

sun illumination. Present and past disposal sites (white arrows) are characterized by high-backscatter material and are especially distinct when the background material is fine-grained sediment, such

as in Stellwagen Basin. The easternmost arrow points to the presently active Massachusetts Bay disposal site, which receives dredged material. The yellow rectangle in the western part of the map is

the location of the new outfall that will discharge treated sewage effluent from the Boston metropolitan area into Massachusetts Bay.
Natural Hazards and Public Safety Theme

Studies on the natural hazards and public safety theme

help scientists to understand the origin and extent of natural hazards in the coastal zone and to characterize their

effects. Natural hazards within coastal and marine environments pose significant threats to human lives and property

and the environment. A priority of the USGS Coastal and

Marine Geology Program is to provide relevant short-term,

predictive earth science information to help prevent loss of

life, property, and land due to coastal erosion, hurricanes,

El Niño, landslides, tsunamis, and earthquakes.

COASTAL EROSION

Coastal erosion is a serious national problem with

immediate and long-term economic and social consequences. Developed areas are threatened with billions of

dollars in property damage as a result of storm impacts and

long-term erosion. In addition, wildlife refuges, critical

habitats, and recreational areas are threatened by coastal

land loss. The USGS is working to provide crucial information on the geologic and oceanographic processes controlling coastal erosion to local, State and Federal agencies

responsible for coastal zone management.

SWASH: SURVEYING WIDE 

AREA OF SHORELINES

The USGS has developed the SWASH system (fig. 16)

for rapid, low-cost, highly accurate measurements of shoreline position using recent advances in the Global

Positioning System (GPS). Tests have shown that the new

system can inexpensively survey more than 65 km of

shoreline within a single low-tide period. SWASH is also

being used to obtain real-time information on shoreline

change during storms. The SWASH system has recently

been used in North Carolina to identify erosional

“hotspots” along a section of the Outer Banks.

SOUTHWEST WASHINGTON

Along the southwest coast of Washington, erosion has

become a serious problem and is costing the State of

Washington and the Federal Government millions of dollars in continued efforts to prevent land loss (fig. 17).

Although there is much speculation as to the causes of

coastal erosion in southwest Washington, until now there

was virtually no relevant scientific or technical information

available. In a long-term, interagency effort, the USGS is

working with its partners to study sediment dynamics in

the region and provide information that will help reduce

the costs and problems associated with coastal erosion.

Cooperators include the Washington Department of

Ecology, the U.S. Army Corps of Engineers, the U.S. EPA,

and Portland State University.

Results suggest that long-term erosion on some of the

beaches within the region has been caused by a sudden 1-

to 2-meter drop in land elevation along the coast due to

large earthquakes that occur approximately every 500

years. Although many beaches have accreted seaward at

Figure 17. Historical erosion at Cape Shoalwater,

Washington, from 1887 to 1995.

Figure 16. SWASH vehicle surveying a North Carolina

beach. USGS photograph.

15
16 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

rates of about 0.5 meter per year over the last 4,000 years,

many are now eroding rapidly. The rock jetties at the

Columbia River mouth have altered patterns of beach

accretion and possibly erosion for tens of kilometers to the

north and south. Discharge of beach sands from the

Columbia River may have been significantly reduced over

the last century due to the series of dams upstream. As

research continues, more data will be forthcoming and will

provide local managers with much needed information.

Visit the web site at http://coastal.er.usgs.gov/

projects98/7242-33780.html for more information.

LOUISIANA BARRIER ISLANDS

The USGS, in cooperation with Louisiana State

University, has documented the long-term historical record

of land loss along Louisiana’s coast as part of the USGS

Louisiana Barrier Island Erosion Study. Data from the project were used to make figure 18, which shows dramatic

change along the Louisiana barrier island coast from 1853

to 1998. Results from this project led to a new understanding of the factors responsible for coastal erosion in the

area and are critical to the effort to stem erosion and

restore coastal barriers and wetlands.

SOUTH CAROLINA

Severe erosion is also occurring along much of the

rapidly developing South Carolina coast. The USGS, in

cooperation with the South Carolina Sea Grant

Consortium and the South Carolina Office of Ocean and

Coastal Resource Management, is conducting research to

examine the causes of coastal erosion. In operation since

1994, this project is producing important information and

products for coastal zone managers. Based on high-resolution, digital sidescan-sonar imagery and sediment collections, a map of the sea floor and sediments is being produced for the regions of Folly Beach and Morris Island.

Historical and recent data have been archived to create an

accurate assessment of shoreline change over time, and

three time periods are being mapped for the area from

Charleston Harbor to Bull’s Bay. Measurements of tides,

oceanographic processes, and geologic information are

presently underway; results will help South Carolina’s

regional managers decide how to best manage their coast.

HAWAII

Over the last century, nearly 30 km (25 percent) of

Oahu’s beaches have been lost or narrowed due to coastal

erosion. Research shows that beach loss occurs where seawalls and other shoreline structures refocus wave energy

and prevent sand accretion. The USGS is working with 

the University of Hawaii and NOAA to study Hawaii’s

beach loss, to identify potential sources of sand for 

renourishment, and to help address Hawaii’s coastal 

erosion problems.

HURRICANES 

Hurricanes are tropical storms that have a sustained

wind speed greater than 120 kilometers per hour. Each

year, hurricanes cause billions of dollars in property loss

and threaten the safety of those living in the Southeastern

United States. The USGS, in collaboration with the

National Aeronautics and Space Administration (NASA),

NOAA, universities, and State agencies, has developed a

strategy to respond to catastrophic storms. The goal is to

improve our understanding of storm impacts within the

coastal zone so that we can better predict the effects of

future events and provide the information needed to manage shoreline development. 

Pre- and post-storm data are now available from

Hurricane Fran in 1996 (fig. 19) and Georges in 1998. The

USGS and its cooperators continue to use state-of-the-art

methods to collect data along the U.S. coastline as a

prestorm baseline, and the storm response team will rapidly deploy after major storm events in the future to measure

impacts such as erosion, overwash, and storm surge. For

more information or photographs, visit the web site at

http://coastal.er.usgs.gov/hurricanes.

In addition to studying hurricane effects on the continental United States, the USGS is also working to help

assess and reduce the impacts of major storms on the

islands of the Pacific.



















  











Figure 18. Dramatic changes in the Isles Dernieres barrier

islands along the Louisiana coast from 1853 to 1998. The erosion of these barriers is largely a natural result of delta plain

evolution. Updated from McBride and others (1991).
NATURAL HAZARDS AND PUBLIC SAFETY THEME 17

EL NIÑO 

El Niño is the periodic warming of equatorial waters

in the western Pacific Ocean that can affect the weather

patterns over large areas of the Earth. During late January

and early February of 1998, the California coast was hit

by a series of powerful El Niño winter storms. At least 27

counties were declared National Disaster Areas, with hundreds of millions of dollars in property losses. Large

waves, high tides and sea level, and extensive rain produced severe coastal erosion. The pre- and post-storm

photographs in figure 20 were taken along the California

coast in early 1998 and show severe erosion. In another

area, the beach was enlarged (fig. 21).

The USGS and its partners have initiated several projects to assess and monitor coastal erosion due to El Niño

and to investigate climate change and its links to geologic

processes. Results so far show that up to 4 meters of land

was lost from several beaches in Monterey and that most

of the property damage was due to landslides.

Maps showing landslide potential for the California

coast under El Niño climate conditions have been proFigure 19. Topsail Island, a developed barrier island off North Carolina: above, the

area on July 17, 1996, post-Hurricane

Bertha/pre-Hurricane Fran; below, the area

on September 7, 1996, post-Hurricane Fran,

showing the dramatic effects of storm surge

overwash. USGS photographs.

Figure 20. The California coast in early

1998 before and after a series of El Niño

winter storms: above, the coast on January

20th before the storms; below, the coast on

February 5th after the storms, showing

severe beach erosion. Photographs by Bruce

Richmond, USGS.

Figure 21. The mouth of Tomales Bay at

Point Reyes National Seashore, California, before (above, October 1997) and

after (below, April 1998) El Niño storms

greatly enlarged the beach. USGS photographs.
18 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

duced and can be obtained from the web site at http://

landslides.cr.usgs.gov/html_files/landslides/usgsnoaa/

index.html. The USGS, NASA, and NOAA have combined efforts by using aerial photography and laser mapping technology to assess coastal erosion and landslides

during El Niño winter storms. 

TSUNAMIS

On July 17, 1998, a magnitude 7.0 offshore earthquake generated a series of catastrophic tsunamis (ocean

waves) that devastated several villages on the northern

coast of Papua New Guinea (PNG). Eyewitnesses reported

waves 7–10 meters high at the coast. Confirmed deaths

were in the thousands, and several villages were totally

destroyed (fig. 22). USGS scientists joined an international team that traveled to PNG to study and learn about the

tsunami event; the team’s goal is to save lives in future

tsunamis.

The USGS produced a qualitative computer simulation (fig. 23) to help visualize the July 1998 tsunami event

and is preparing a more quantitative version. Coastal and

marine researchers are trying to estimate how often such

events happen by examining the sediments of the region

for evidence of previous events of a similar nature.

Scientists found a layer of sediments some 120 centimeters below the surface that is indicative of a previous

tsunami and are now trying to determine the approximate

time of the event.

In an effort to learn more about tsunamis and to make

coastal communities aware of potential tsunami hazards,

USGS scientists are investigating the past occurrences of

tsunamis in the Caribbean and in the Pacific Northwest.

LANDSLIDES

In February 1995, a 500-meter section of a popular

beach at Michigan’s Sleeping Bear Dunes National

Lakeshore suddenly slid into the waters of northeastern

Lake Michigan. The National Park Service immediately

requested that the USGS help to assess the hazard for

future landslides at the lakefront site. USGS research indicates that landslides at Sleeping Bear Point are related to

the release of water trapped within the dune sand, typically during unseasonably warm weather in winter months.

Results are helping managers to identify times when landslide hazards are high and when public access to the beach

should be restricted. Information will also be used to educate and warn the general public of impending landslide

hazards. A summary of the USGS research is available on

the web at http://wrgis.wr.usgs.gov/fact-sheet/fs020-98.

The USGS studies many types of landslides. For more

information, see the web site at http://landslides.usgs.gov/

html_files/nlicsun.shtml.

EARTHQUAKES

The USGS Coastal and Marine Geology Program

works in concert with the USGS Earthquake Hazards

Reduction Program to study earthquake hazards both on

land and offshore. For more information, see the web site

at http://geohazards.cr.usgs.gov/earthquake.html. An

example of research on earthquakes in the Pacific

Northwest is described below.

The Pacific Northwest is the site of the Cascadia

Subduction Zone, where the Juan de Fuca plate is diving

beneath the North American plate. Scientists at the USGS

are surveying the region and modeling fault stresses and

strain to better understand and predict earthquakes in the

region. So far, the study indicates that long-term uplift

along coastal Washington and Oregon is typical of deformation that occurs between major earthquakes along a

subduction zone. Results will be used to update regional

fault maps within the coastal zone and provide new information on the potential magnitude and recurrence rate of

earthquakes in the region; recent studies show that seismic

risks for the Pacific Northwest coast are greater than previously thought. This project will help regional administrators and planners to identify areas with significant

earthquake risk and to better define the hazards posed.

Figure 23. One frame of a USGS computer

simulation of the tsunamis that hit Papua New

Guinea on July 17, 1998. The complete simulation is available from the web site at http://

walrus.wr.usgs.gov/tsunami/PNGhome.html.

Figure 22. Damage caused by the tsunamis

that hit Papua New Guinea on July 17, 1998.

Photograph by Guy Gelfenbaum, USGS.
Research efforts under the natural resources theme

focus on understanding the Nation’s fresh-water, mineral,

and energy resources in a global, geologic, economic, and

environmental context. Studies are conducted to evaluate

resource potential and to assess possible hazards and

impacts on the environment associated with resource use.

The USGS Coastal and Marine Geology Program is providing critical information on gas hydrates, ground water,

and sand and gravel resources.

ENERGY

METHANE GAS HYDRATES

Although gas hydrates offer a new and untapped

source of energy, they also pose a significant hazard to

offshore operation and may play an important role in climate change. Gas hydrates are a solid crystalline form of

water, like ice, except that they contain additional gas, typically methane. Gas hydrates are widely stored in oceanfloor sediments. Extraction of methane gas from hydrates

could provide a very large energy and petroleum resource.

Increased temperature or decreased pressure can cause gas

hydrates to dissociate and result in sea-floor instability and

undersea landslides; evidence of past blowouts is indicated

by seismic-reflection profiles (fig. 24). Consequently,

hydrates pose a serious safety threat to offshore drilling

operations. If methane in hydrates is released, it may play

a significant role in global climate change.

The USGS is leading the study of gas hydrates, mapping their occurrence, studying their geologic and chemical properties, and assessing their effects on sea-floor stability. Mapping by the USGS has revealed large accumulations of methane hydrates off the coasts of North and

South Carolina. 

GULF OF MEXICO

The Texas-Louisiana continental slope is one of the

few remaining frontiers for hydrocarbon exploration within our Nation’s Exclusive Economic Zone. Detailed mapping of the sea floor and identification of potential hazards

to drilling and platform stability are essential to the oil

industry. USGS scientists are working with researchers

from the University of Texas, Texas A&M University, and

others to develop a detailed understanding of the tectonic

and sedimentary conditions controlling underwater landslides in the area. Mapping so far has identified areas of

mass wasting and faulting, and seismic profiles show

regions influenced by underlying accumulations of salt

and possible gas hydrates.

GROUND WATER

Fresh ground water, one of our Nation’s most important resources, is vulnerable to contamination from saltwater intrusion at the coast, disposal of sewage wastes, and

agricultural runoff. The USGS Coastal and Marine Geology

Program is working with regional partners to study aquifer

geology, to identify sources and processes of contamination, and to help preserve our freshwater supplies.

Natural Resources Theme

19

Base

Sea floor

Collapsed area

Figure 24. Seismic profile of the sea floor off South Carolina showing a large collapse area at the crest of the Blake Ridge; the collapse was probably caused by a blowout releasing considerable methane from gas hydrates. From Taylor and others (1999). TWTT(S),

two-way travel time in seconds; VE, vertical exaggeration; SP, shot point; Base, the base of the gas hydrate layer, which extends to the

sea floor.
20 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

In the Florida Keys, concern over the fate of sewage

waste injected into underlying, porous limestone prompted

the USGS to mount a significant effort to study and monitor ground-water flow and potential contamination. More

than 84 monitoring wells have been drilled, and research

has revealed several important properties of ground-water

movement in the Keys. Tides and sea-level variations

drive ground-water flow primarily perpendicular to the

islands and to the east. Studies also suggest that because

seaward movement of potentially contaminated ground

water is limited, the reef tract may not be substantially

threatened; however, nearshore environments can be

affected. This important study led to the modification of

State regulations regarding the installation of sewage disposal wells in the Florida Keys.

MARINE SAND AND GRAVEL

Sand and gravel resources are essential to all coastal

communities, providing materials to construct roads and

buildings and to renourish beaches. Successful coastal

zone management requires knowledge of sediment

sources, sinks, and transport pathways. The USGS is helping to identify offshore sources of sand and gravel that

have potential for use as fill material.

SOUTHERN LONG ISLAND

Coastal erosion and the need for sand resources along

the south shore of Long Island, New York, have received 

great attention from engineers, scientists, and politicians

during the last 40 years. The USGS and the U.S. Army

Corps of Engineers are investigating the processes responsible for erosion and are determining the availability of

sand resources for beach nourishment in the region (fig.

25). Along Fire Island National Seashore, results are

showing a solid link between offshore geology and shoreline erosion. It appears that the underlying regional geology is the principal control on long-term patterns of beach

erosion.

FLORIDA

A 5-year geologic study of Florida’s west-central

coast has provided important information for regional

managers concerned about beach erosion and sources of

sand for renourishment. Results indicate that most beachquality sand is concentrated off tidal inlets and in long,

linear ridges. Research suggests that although coarse carbonate sand is being produced in the modern environment,

there are few or no modern sources of beach-quality

quartz sediment in the region. USGS scientists, in cooperation with the University of South Florida, are measuring

and modeling oceanographic processes in the area to better

understand sediment transport pathways and coastal erosion and to find sources of clean sand suitable for renourishing eroded beaches.

Figure 25. Offshore sand resources south of Long Island that may be used for beach replenishment. From Bill

Schwab, USGS, unpublished data.
The overall goals of research under the information

and technology theme are to provide a national source of

technology and information to better the Nation’s understanding of coastal and marine environments. Major

efforts of the USGS Coastal and Marine Geology Program

are underway to systematically map the Nation’s coastal

and nearshore sea floor and sediments and to provide a

comprehensive geologic data base easily accessed by the

public.

SEA-FLOOR MAPPING

For years, managers, policymakers, and those conducting research in coastal and marine environments faced

a vexing problem—an almost complete lack of accurate

sea-floor base maps. The USGS and its partners are using

high-resolution, multibeam systems and advanced dataprocessing techniques to systematically map the sea floor

and sediments of the U.S. continental shelf and, in particular, areas of critical economic or biologic importance. 

GLORIA IMAGERY OF THE 

U.S. EXCLUSIVE ECONOMIC ZONE

On March 10, 1983, President Reagan declared an

expansion of the United States’ sovereign rights to all natural resources within a zone extending to 200 nautical

miles beyond the shoreline. The proclaimed Exclusive

Economic Zone (EEZ) provided a mandate for exploration

and resource utilization. However, although the general

bathymetry was known, few, if any maps or detailed information on sea-floor topography, benthic habitats, or sediment distribution existed. 

From 1984 to 1991, the USGS and its partners

mapped the EEZ by using a long-range sidescan-sonar

system called GLORIA. The system was specifically

designed to document the morphology and texture of features in the deep ocean (water depths greater than 200

meters). Advanced computer software was then developed

by the USGS to enhance the GLORIA imagery.

A CD-ROM containing the GLORIA imagery of the

EEZ is now available from the USGS (Groome and others,

1997); a sample image is shown in figure 26. Information

and data can also be obtained at http://walrus.wr.usgs.gov/

docs/gloria/.

OTHER SEA-FLOOR MAPPING

The USGS is mapping the sea floor, sediments, and

biologic habitats in areas not mapped by GLORIA (some

of which have already been mentioned) and is testing new

technology. Tools include multibeam-sonar systems, which

provide high-quality bathymetry and quantitative backscatter data used to make shaded-relief maps and perspective views (fig. 27). Many partners are working with the

USGS on sea-floor mapping; these include the University

of New Brunswick, the U.S. Army Corps of Engineers, the

U.S. EPA, NOAA, and the University of Hawaii. Table 1

has a list of regions for which sea-floor maps are available.

Information and Technology Theme

Figure 26. Perspective view of the 

sea floor off western Florida based on

GLORIA sidescan-sonar imagery from

the USGS and bathymetry from NOAA.

The image shows the Florida Escarpment

cut by gullies and valleys, a meandering

channel formed at water depths of more

than 3,000 meters, and mass-wasting

fan deposits that bury the channel and

that originated in the Mississippi Canyon

500 kilometers to the northwest. From

Groome and others (1997).

Debris 

aprons

Valleys

Fan deposits Meandering channel

21
22 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

AIRBORNE LASER MAPPING (LIDAR)

Airborne laser mapping (LIDAR) systems provide an

unprecedented potential for cost-effective, precise, and

rapid mapping of coastal topography and nearshore

bathymetry. The USGS and its collaborators are testing

and comparing several LIDAR systems (fig. 28) to determine their utility in applications such as bottom characterization, pre- and post-storm assessments, and shoreline

monitoring. Partners in this effort include the U.S. Army

Corps of Engineers, NASA, NOAA, Oregon State

University, Scripps Institution of Oceanography, North

Carolina State University, and the Naval Research

Laboratory. 

COMPUTER MODELING

USGS scientists and their partners develop and use

state-of-the-art computer simulations to study geologic

and oceanographic phenomena and to provide managers

and policymakers with the best scientific information possible. Recent projects using computer simulations include

modeling of circulation in Massachusetts Bay, in Lake

Figure 27. Perspective view looking northeast from the Pacific

Ocean toward Los Angeles and Palos Verdes, California. The

view was constructed from multibeam mapping data collected in

1996, 1998, and 1999 by the USGS and its partners; see the web

site at http://walrus.wr.usgs.gov/pacmaps/la_pers2.html. The

greater Los Angeles area is home to more than 10 million people, who put pressure on the adjacent offshore continental shelf

and margin with activities such as ocean disposal for dredged

spoils, explosive disposal, waste-water outfall, and commercial

fishing. The data collected in 1996–99 have been used to compile the first highly accurate maps of the continental shelf and

slope to serve as a base for multidisciplinary research on the

coastal environment.

Table 1. Sea-floor images by the USGS Coastal and Marine Geology Program and cooperators.

Page where 

Region mapped discussed in Web site or reference

this Circular

Western United States

Pacific sea floor (Hawaiian Islands, San Diego, Los Angeles) p. 22 http://walrus.wr.usgs.gov/pacmaps/; Dartnell and 

Gardner (1999)

San Francisco Bay p. 10 http://terraweb.wr.usgs.gov/TRS/projects/SFBaySonar/;

http://sfbay.wr.usgs.gov/access/mapping/multibeam/;

Dartnell and Gardner (1999)

Monterey Bay National Marine Sanctuary p. 13 http://terraweb.wr.usgs.gov/TRS/projects/

MontereySonar/

Lake Tahoe ––– http://blt.wr.usgs.gov/tahoe/openfile.html; Gardner 

and others (2000)

Gulf of Mexico and Southeastern United States

Gulf of Mexico p. 21 http://coastal.er.usgs.gov/east_gulf/

Lake Pontchartrain p. 10 http://coastal.er.usgs.gov/pontchartrain/imagery/

Florida Keys p. 13 Lidz and others (1997)

West Florida p. 20 Briere and others (2000)

Oculina Bank off east-central Florida p. 13 Scanlon and others (1999)

Northeastern United States

New York, New Jersey Bight p. 7 Schwab and others (1997)

Long Island Sound p. 8 Poppe and others (1997, 1998a,b); Twichell and others 

(1997, 1998); Knebel and others (1999)

Stellwagen Bank National Marine Sanctuary p. 13 Valentine and others (2000)

Massachusetts Bay and Boston Harbor p. 7, 24 Bothner and others (1992); Butman and Lindsay (2000)
INFORMATION AND TECHNOLOGY THEME 23

Pontchartrain, and off the West Coast of Florida and

recreating the devastating tsunami that hit Papua New

Guinea in 1998. Figure 29 depicts the tidal flushing of

Boston Harbor based on computer simulations.

REMOTE SENSING OF

THE COASTAL OCEAN

Satellite imagery is providing a new frontier for

oceanographic research and coastal and marine management. Advances in remote-sensing techniques now allow

for large-scale, synoptic overviews of water temperature

and turbidity on a near-real-time basis. The USGS and its

partners are producing and making available on the World

Wide Web daily data on sea-surface temperature and

water turbidity for South Florida as shown in figure 30

(http://coastal.er.usgs.gov/flbay/), and the eastern Gulf of

Mexico (http://coastal.er.usgs.gov/east_ gulf/). Data are

available for the East Coast from New York south, the

Gulf Coast and Lake Pontchartrain, the West Coast from

Monterey north, and San Francisco Bay. Current work is

focused on making data more accessible, including development of georeference standards and the integration of

new ocean color data as they become available.

DEVELOPING AND TESTING 

NEW TECHNOLOGIES

A wide array of instruments is needed to characterize

coastal and marine regions. The USGS Coastal and

Marine Geology Program tests commercially available

systems and develops new instruments for its special

needs. Two custom-built systems are described next.

OCEAN BOTTOM SEISMOMETER (OBS)

The Ocean Bottom Seismometer (OBS) is a self-contained, low-cost system developed by the USGS to acquire

seismic data on the sea floor (fig. 31); it is easily deployed

and retrieved. The OBS is designed to fall freely to the sea

floor and to record shock wave information from earthquakes or geophysical instruments. Twelve OBS’s are currently in operation and have been used to study a wide

range of important geologic features throughout the world,

including gas hydrates, sea-floor sediments, and the underlying structure of the Earth’s crust. More information is

available from the web site at http://obs.er.usgs.gov/

index_text.html.

Figure 28. Elliptical scan pattern of NASA’s airborne laser mapper (LIDAR) system operated from a

NOAA Twin Otter aircraft. New LIDAR mapping technology is leading to high-resolution information

about the Nation’s coasts. For example, data collected by the USGS and its partners before and after

storms document the extent of beach erosion.
24 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

GAS HYDRATE AND SEDIMENT TEST

LABORATORY INSTRUMENT (GHASTLI)

Scientists at the USGS have created a unique, custombuilt computer-controlled laboratory system, GHASTLI, to

study the in situ properties of gas hydrates and hydraterelated processes (fig. 32). GHASTLI provides the first

link between theoretical and field studies of gas hydrates

and will serve as a tool to improve gas hydrate recognition

and assessment.

INFORMATION PRODUCTS 

The USGS Coastal and Marine Geology Program is

committed to providing the most relevant, credible, and

objective scientific information possible. The results of

program studies are easily accessible to Federal and State

governments, the public, industry, and the scientific community. The web sites mentioned in this Circular describe

a wide range of information in both digital and hard-copy

formats.

Figure 30. Satellite images of Florida Bay showing sea-surface

temperature in degrees Celsius (left) and reflectance in percent

(right). Reflectance values at the red end of the bar scale indicate

high turbidity.

Figure 29. One frame of a computer simulation of tidal flushing of Boston Harbor.

Water in Boston Harbor is shown in red;

other colors represent it mixing with the

blue Massachusetts Bay water. Computer

models like this one are aiding environmental restoration.

Figure 32. Part of the GHASTLI

system built by the USGS to study

gas hydrates. USGS photograph.

Figure 31. Ocean Bottom

Seismometer (OBS), which

was developed by the USGS

to acquire seismic data on the

sea floor. USGS photograph.
The U.S. Geological Survey and its Coastal and

Marine Geology Program are committed to serving the

Nation’s needs in earth science monitoring, research, and

assessment. Future efforts will continue to provide fundamental geologic information while responding to new

areas of interest or concern as they arise. Although topics

of study will typically be either national or regional in

extent, when warranted, more localized demonstration

projects will be conducted. Geologic hazards, resources,

climate change impacts, ecosystem function, human

health, and ground-water issues will continue to be the

focus of future efforts of the Coastal and Marine Geology

Program. Future directives for the program include the

topics discussed below.

CORAL REEFS

Coral reefs are critical habitats for the United States

and for many developing nations in the tropics. They provide vast resources through their biodiversity, protection

against destructive wave forces, supply of sand for nearby

beaches, appeal to tourists, and importance to recreational

and commercial fishing. Changes in sea level, water quality, global warming, adjacent land usage and drainage,

coastal construction, overfishing, ship groundings, and the

proliferation of diseases are all factors placing coral reefs

at risk. The USGS has begun projects of coral reef

research and thematic mapping coordinated with other

Department of the Interior agencies (National Park

Service, Fish and Wildlife Service) and NOAA.

The USGS efforts will focus on providing a better

understanding of the factors that influence coral reef

growth, regional diversity, distribution, and productivity.

By mapping coral reef locations and ground-checking

diversity and health, the USGS will help to develop a clear

understanding of how waves, the underlying sea-floor

morphology, sedimentation, water clarity, and water quality influence reef growth. State and Federal managers in

coral reef regions, such as Hawaii, Florida, the U.S.

Territories, and other island nations, will be able to use

this information to better balance the protection of reefs

with the activities of growing coastal populations.

MAPPING OF SEA-FLOOR HABITATS

Recently, the USGS Coastal and Marine Geology

Program, in cooperation with NOAA, held a workshop to

review research needs regarding benthic marine habitats,

specifically in areas where a poor understanding exists of

relations between fundamental geologic processes and biologic habitats, resources, and health. Over 50 marine scientists and managers participated in the workshop. Three

themes of national importance were discussed: habitat

characterization, natural and human-induced effects on

habitats, and coral reefs. In addition, several specific

regions were identified as areas of concern. These include

the Northeast and Great Lakes, Southeast and Gulf of

Mexico, West Coast, Alaska, and Hawaii, and low-latitude

coral reef environments.

Workshop results suggest that research is needed in

benthic habitats where fishing pressures are increasing

while fisheries are declining, and where habitat degradation is occurring due to manageable activities such as poor

fishing practices, pollution, and coastal development. If

recent legislation to preserve biologic habitats is to succeed, knowledge about benthic habitats, human influences,

and ecosystem functioning is essential.

Participants developed a comprehensive list of

research requirements. For all of the areas discussed, it

was clear that accurate, accessible maps of the sea floor

and its geologic and biologic composition are critically

needed. As a result of the workshop, the USGS Coastal

and Marine Geology Program, along with its partners, has

made the mapping and study of benthic habitats, particularly in areas of national and regional concern, one of its

highest priorities for the future. 

UNDERSTANDING COASTAL

AND INNER SHELF SYSTEMS

Geologic framework and processes are critically

important in determining erosion, accretion, and sediment

budgets for coastal and nearshore regions. This area of

research will be a major focus for the Coastal and Marine

Geology Program over the next decade.

STORM IMPACTS IN 

THE COASTAL ZONE

The USGS will continue its efforts to better predict

storm impacts on coastal landforms. A hurricane response

team is now in place and will continue to provide critical

information about preventing property damage and loss of

life and land along the shore. The Coastal and Marine

Geology Program will also continue to develop technology such as SWASH to better monitor and assess coastal

land loss and change.

Future Research

25
26 USGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS AND ACHIEVEMENTS

RELATIVE SEA-LEVEL RISE

Sea-level rise due to global climate change and land

subsidence is of great national and worldwide concern.

The USGS Coastal and Marine Geology Program will

continue to study natural and human-induced sea-level

change and help to predict the environmental impacts of

climate change.

METHANE GAS HYDRATES

Gas hydrates are a new and developing frontier in

terms of energy resources, offshore hazards, and climate

change. The USGS is taking a leadership role in the study

of gas hydrates and hydrate-related processes.

GEOLOGIC CONTROLS ON 

GROUND-WATER RESOURCES

Freshwater is one of the Nation’s most valuable

resources. Study of ground-water resources and the geologic controls on their supply, flow, and potential contamination will continue to be a priority for the Coastal and

Marine Geology Program.

DEEPWATER GULF OF MEXICO

The deepwater region of the Gulf of Mexico may be

the last unexploited source of petroleum resources in or

near the continental United States. The USGS is committed to continue its work to assess offshore hazards and to

determine the geologic structure and history of the region.

REGIONAL STUDIES

Future research efforts are planned for the coastal and

marine environments in regions of specific interest, two of

which are North Carolina and the southeast region. The

Coastal and Marine Geology Program is working to develop a strategy for projects that meet regional science needs.
Bothner, M.H., Parmenter, C.M., Twichell, D.C., Polloni, C.F., 

and Knebel, H.J., 1992, A geologic map of the sea floor in 

western Massachusetts Bay, constructed from digital sidescan-sonar images, photography, and sediment samples, 

with display software by R.A. Ambroziak: U.S. Geological 

Survey Digital Data Series DDS–3, one CD-ROM. 

Briere, P.R., Scanlon, K.M., Gledhill, C.T., Koenig, C.C., and 

Fitzhugh, Gary, 2000, West Florida Shelf; Sidescan-sonar 

and sediment data from shelf-edge habitats in the northeastern Gulf of Mexico: U.S. Geological Survey Open-File 

Report 99–589, one CD-ROM.

Butman, Bradford, Bothner, Michael, Knebel, H.J., Manheim, 

F.T., Bucholtz ten Brink, Marilyn, and Signell, R.P., 1998, 

Predicting the long-term fate of sediments and contaminants 

in Massachusetts Bay: U.S. Geological Survey Fact Sheet 

FS–172–97, 6 p.

Butman, Bradford, and Lindsay, John, eds., 2000, A marine GIS 

library for Massachusetts Bay; Focusing on disposal sites, 

contaminated sediments, and sea floor mapping: U.S. 

Geological Survey Open-File Report 99–439, one CD-ROM.

Dartnell, Peter, and Gardner, J.V., 1999, Sea-floor images and 

data from multibeam surveys in San Francisco Bay, southern California, Hawaii, the Gulf of Mexico, and Lake 

Tahoe, California-Nevada: U.S. Geological Survey Digital 

Data Series DDS–55, one CD-ROM.

Gardner, J.V., Mayer, L.A., and Hughes Clarke, J.E., 2000, 

Morphology and processes in Lake Tahoe (CaliforniaNevada): Geological Society of America Bulletin, v. 112, 

no. 5, p. 736–746.

Groome, M.G., Gutmacher, C.E., and Stevenson, A.J., 1997, 

Atlas of GLORIA sidescan-sonar imagery of the Exclusive 

Economic Zone of the United States; EEZ-View: U.S. 

Geological Survey Open-File Report 97–540, one CD-ROM.

Knebel, H.J., 1998, Sedimentary environments in Long Island 

Sound: A guide to sea-floor management in a large urbanized estuary: U.S. Geological Survey Fact Sheet 

FS–041–98, 2 p.

Knebel, H.J., Signell, R.P., Rendigs, R.R., Poppe, L.J., and List, 

J.H., 1999, Maps showing acoustic and textural characteristics and distribution of bottom sedimentary environments in 

Long Island Sound, Connecticut and New York: U.S. 

Geological Survey Geologic Investigations Series I–2659, 

2 sheets.

Lidz, B.H., 1997, Environmental quality and preservation—

Fragile coral reefs of the Florida Keys; Preserving the 

largest reef ecosystem in the continental U.S.: U.S. 

Geological Survey Open-File Report 97–453, 5 p. (Also 

available on the web at http://sflwww.er.usgs.gov/

publications/ofr/97-453/.)

Lidz, B.H., Shinn, E.A., Hansen, M.E., Halley, R.B., Harris, 

M.W., Locker, S.D., and Hine, A.C., 1997, Maps showing 

sedimentary and biological environments, depth to 

Pleistocene bedrock, and Holocene sediment and reef thickness from Molasses Reef to Elbow Reef, Key Largo, south 

Florida: U.S. Geological Survey Miscellaneous 

Investigations Map I–2505, 3 sheets, scale 1:24,000.

Lough, R.G., Valentine, P.C., Brown, C.L., and Michaels, W.L., 

1992, Maps showing the distribution of juvenile cod in 

relation to the sedimentary environment of eastern Georges 

Bank: U.S. Geological Survey Open-File Report 92–566, 

1 sheet.

Manheim, F.T., ed., 1999, Lake Pontchartrain Basin; Bottom 

sediments and regional scientific and educational resources: 

U.S. Geological Survey Open-File Report 98–805, available 

only on the web at http://woodshole.er.usgs.gov/cdroms/

ofr98-805/.

McBride, R.A., Penland, Shea, Jaffe, B.E., Williams, S.J., 

Sallenger. A.H., Jr., and Westphal, K.A., 1991, Shoreline 

changes of the Isles Dernieres barrier island arc, Louisiana, 

from 1853 to 1989: U.S. Geological Survey Miscellaneous 

Investigations Map I–2186, 1 sheet, scale 1:75,000.

Poag, C.W., 1998, The Chesapeake Bay bolide impact: A new 

view of coastal plain evolution: U.S. Geological Survey 

Fact Sheet FS–049–98, 2 p.

Poppe, L.J., Lewis, R.S., Denny, J.F., Parolski, K.F., and 

DiGiacomo-Cohen, M.L., 1998a, Sidescan sonar image, 

surficial geologic interpretation, and bathymetry of the 

Fishers Island Sound sea floor, Connecticut, New York, and 

Rhode Island: U.S. Geological Survey Miscellaneous 

Investigations Series Map I–2640, 2 sheets, scale 1:12,500 

and 1:15,000.

Poppe, L.J., Lewis, R.S., Denny, J.F., Parolski, K.F., DiGiacomoCohen, M.L., and Tolderlund, D.S., 1998b, Sidescan sonar 

image, surficial geologic interpretation, and bathymetry of 

the Long Island Sound sea floor in Niantic Bay and vicinity, 

Connecticut: U.S. Geological Survey Miscellaneous 

Geologic Investigations Series Map I–2625, 2 sheets, scale 

1:11,750 and 1:20,000.

Poppe, L.J., Lewis, R.S., Zajac, R.N., Twichell, D.C., Schmuck, 

E.A., Parolski, K.F., and DiGiacomo-Cohen, M.L., 1997, 

Sidescan sonar image, surficial geologic interpretation, and 

bathymetry of the Long Island Sound sea floor off 

Hammonasset Beach State Park, Connecticut: U.S. 

Geological Survey Miscellaneous Investigations Series Map 

I–2588, 2 sheets, scale 1:7,500 and 1:15,000.

Scanlon, K.M., Briere, P.R., and Koenig, C.C., 1999, Oculina 

Bank—Sidescan sonar and sediment data from a deep-water

coral reef habitat off east-central Florida: U.S. Geological 

Survey Open-File Report 99–10, one CD-ROM.

Schwab, W.C., Corso, W., Allison, M.A., Butman, B., Denny, 

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SGS COASTAL AND MARINE GEOLOGY RESEARCH—RECENT HIGHLIGHTS—U.S. Geological Survey Circular 1199