U.S . DE P AR T ME NT OF C O MME R C E

NAT OI NAL OCE ANIC AND ATMOS PHER IC ADMINIS TR AT OI N

Newport

Point Reyes

A Tsunami Forecast Model for Point Reyes, California 

NOAA OAR Special Report

Michael C. Spillane

NOAA Center for Tsunami Research (NCTR)

Pacic Marine Environmental Laboratory

PMEL Tsunami Forecast Series: Vol. 6

doi:10.7289/V5W9573D 
Front cover image: Overview of NOAA tsunami forecast system. Top frame 

illustrates components of the tsunami forecast using the 11 March 2011 Tohoku 

tsunami as an example: DART systems (black triangles), precomputed tsunami 

source function database (unfilled black rectangles) and high-resolution forecast 

models in the Pacific, Atlantic, and Indian oceans (red squares). Colors show 

computed maximum tsunami amplitudes of the offshore forecast. Black contour 

lines indicate tsunami travel times in hours. Lower panels show the forecast process 

sequence left to right: tsunami detection with the DART system (third generation 

DART ETD is shown); model propagation forecast based on DART observations; 

coastal forecast with high-resolution tsunami inundation model.

PDF versions of the PMEL Tsunami Forecast Series reports are available at

http://nctr.pmel.noaa.gov/forecast_reports
PMEL Tsunami Forecast Series: Vol. 6

A Tsunami Forecast Model for Point Reyes, California

M.C. Spillane1,2

1 Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington, 

Seattle, WA

2  NOAA/Pacific Marine Environmental Laboratory (PMEL), Seattle, WA

NOAA OAR Special Report

November 2014

UNITED STATES

DEPARTMENT OF COMMERCE

Penny Pritzker

Secretary

NATIONAL OCEANIC AND

ATMOSPHERIC ADMINISTRATION

Kathy Sullivan

Under Secretary for Oceans

and Atmosphere/Administrator

Office of Oceanic and

Atmospheric Research

Craig McLean 

Acting

Assistant Administrator

doi:10.7289/V5W9573D 
NOTICE from NOAA

Mention of a commercial company or product does not constitute an endorsement by NOAA/

OAR. Use of information from this publication concerning proprietary products or the tests of

such products for publicity or advertising purposes is not authorized. Any opinions, findings,

and conclusions or recommendations expressed in this material are those of the authors and 

do not necessarily reflect the views of the National Oceanic and Atmospheric Administration.

Also available from the National Technical Information Service (NTIS)

(http://www.ntis.gov)

Contribution No. 3401 from NOAA/Pacific Marine Environmental Laboratory

Contribution No. 2088 from Joint Institute for the Study of the Atmosphere and Ocean (JISAO)
Contents

Foreword xi

Abstract 1

1. Background and Objectives 3

1.1 The setting 3

1.2 Natural hazards 4

1.3 Tsunami warning and risk assessment 8

2. Forecast Methodology 9

2.1 The tsunami model 9

2.2 NOAA’s tsunami forecast system 9

3. Model Development 11

3.1 Digital elevation models 11

3.2 Tides and sea level variation 12

3.3 The CFL condition and other considerations for grid design 13

3.4 Specifics of the model grids 14

3.5 Model run input and output files 15

4. Results and Discussion 17

4.1 The micro-tsunami tests 17

4.2 The mega-tsunami tests 19

4.3 Model validation: The 2011 Honshu tsunami 21

4.4 Model validation with other preferred historical events 24

4.5 Other historical simulations of interest at Point Reyes, California 25

4.6 The Mendocino earthquake of 25 April 1992 27

4.7 Simulation of the remaining synthetic mega-tsunami events 28

5. Conclusions 31

6. Acknowledgments 31

7. References 33

FIGURES 37

Appendix A. 101

A1. Reference model *.in file for Point Reyes, California 101

A2. Forecast model *.in file for Point Reyes, California 102

Appendix B. Propagation Database: Pacific Ocean Unit Sources 103

Contents iii 
Appendix C. Synthetic Testing Report: Point Reyes, California 151

C1. Purpose 151

C2. Testing procedure 151

C3. Results 152

Glossary 161

iv Contents
List of Figures

1 The Point Reyes area of west and south Marin County, California. 39

2 Extract from oblique 3-D view of the San Francisco DEM provided

by NGDC. 40

3 View of the Point Reyes headland and Drakes Bay in its lee. 40

4 Distribution of the historical tsunami sources employed for the

development of the Point Reyes forecast model. 41

5 A sample time interval from the Point Reyes tsunami-capable tide

gauge, unrelated to tsunami activity. The evolving surface wave

spectrum is shown in the lower panel. 42

6 The setting of Point Reyes and its nested forecast model grids. The

C grids of other West Coast forecast models are marked, as are

various sites with data available for this study. 43

7 Nested grid representation for the Point Reyes reference model. 44

8 Nested grid representation for the Point Reyes forecast model. 45

9 Comparison of the reference and forecast model time series at the 

warning point for three Western Pacific micro-tsunami sources. 46

10 Locations of synthetic tsunami scenarios employed in model

development. Three micro-tsunami scenarios and the Mw 7.5 case

employ a single unit source; 19 combine 10 pairs of unit sources to

model mega-tsunamis. 47

11 Comparison of reference and forecast model results for the synthetic 

ACSZ 56–65 mega-tsunami representing Cascadia Subduction Zone.

(a) Distributions of maximum amplitude; (b) distributions of maximum

speed; (c) comparison of wave amplitude and currents during the first

wave peak; (d) as in (c) but at a later time when reference and

forecast model solutions have diverged somewhat. 48

12 Comparison of reference and forecast model results for the synthetic 

KISZ 01–10 event representing Kamchatka. (a) Distributions of

maximum amplitude; (b) distributions of maximum speed;

(c) comparison of wave amplitude and currents during the first wave

peak; (d) as in (c) but at a later time near the end of the simulation. 52

13 Comparison of reference and forecast model results for the synthetic

NTSZ 30–39 event representing Samoa. (a) Distributions of

maximum amplitude; (b) distributions of maximum speed;

(c) comparison of wave amplitude and currents during the first wave

peak; (d) as in (c) but at a later time when the reference and forecast

model solutions have diverged somewhat. 56

Contents v 
14 Comparison of reference and forecast model results for a moderate

synthetic event at NTSZ 36 near Samoa. (a) Distributions of maximum

amplitude; (b) distributions of maximum speed; (c) comparison of wave

amplitude and currents during the first major wave peak; (d) as in (c)

but at a later time when the reference and forecast model solutions

have diverged somewhat. 60

15 Observed time series from DART® and MARS bottom pressure

sensors during the 2011 Honshu event, compared with the forecast

model representation based on the propagation database. 64

16 Comparison of observations with reference and forecast modelpredicted time series for the historical 2011 Honshu event at locations

where tide gauge data are available: (a) Point Reyes, Arena Cove, and

San Francisco; (b) Bolinas (6-min data), Alameda, and Richmond. 65

17 Comparison of reference and forecast model results for the historical 

2011 Honshu event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents during the first wave peak; (d) as in (c) but during a later

wave peak; (e) as in (c) and (d) but during a later wave trough. 66

18 Inundation forecast from the reference model C grid for the 2011

Honshu event, compared with the CalEMA inundation line. Inset:

tide gauge data from Point Reyes. 71

19 Comparison of reference and forecast model results for the historical 

2010 Chile event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents during the first wave peak. 72

20 Modeled and observed time series comparison for the historical 2010

Chile event. 75

21 Comparison of reference and forecast model results for the historical 

2009 Samoa event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents at a time between waves at the reference point. 76

22 Modeled and observed time series comparison for the historical 2009

Samoa event. 79

23 Comparison of reference and forecast model results for the historical

2006 Kuril event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents during the first wave peak. 80

24 Modeled and observed time series comparison for the historical 2006

Kuril event. 83

25 Comparison of reference and forecast model results for the historical

1964 Alaska event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents during the first wave peak. 84

vi Contents
26 Modeled and observed time series comparison for the historical 1964

Alaska event. 87

27 Comparison of reference and forecast model results for the historical 

1946 Unimak event. (a) Distributions of maximum amplitude;

(b) distributions of maximum speed; (c) comparison of wave amplitude

and currents during a later wave peak. 88

28 Modeled and observed time series comparison for the historical 1946

Unimak event. 91

29 Modeled and observed time series comparison for the Sanriku event

of 15 June 1896. 92

30 Modeled and observed time series comparison for the Kamchatka

event of 4 November 1952. 92

31 Modeled and observed time series comparison for the Chile event of

22 May 1960. 93

32 Modeled and observed time series comparison for the Andreanof

event of 10 June 1996. 93

33 Modeled and observed time series comparison for the Peru event of

23 June 2001. 94

34 Modeled and observed time series comparison for the Hokkaido event

of 25 September 2003. 94

35 Modeled and observed time series comparison for the Rat Island

event of 17 November 2003. 95

36 Modeled and observed time series comparison for the Tonga event of

3 May 2006. 95

37 Modeled and observed time series comparison for the normal thrust

event off the Kuril Islands on 13 January 2007. 96

38 Modeled and observed time series comparison for the Solomon event

of 1 April 2007. 96

39 Modeled and observed time series comparison for the Peru event of

15 August 2007. 97

40 Modeled and observed time series comparison for the Chile event of

14 November 2007. 97

41 The Cape Mendocino event of 25 April 1992. Panels show frequency

of non-thrust events in the vicinity and a comparison of the forecast

model with observations at Arena Cove and Point Reyes. 98

42 Predicted maximum sea level (from the forecast model) at the Point

Reyes tide gauge that might result were mega-tsunamis to occur at

various locations around the Pacific basin. 99

43 Chart of the area inundated by one or more of the mega-tsunami

scenarios based on the forecast model. 100

Contents vii 
B1 Aleutian–Alaska–Cascadia Subduction Zone unit sources. 105

B2  Central and South America Subduction Zone unit sources. 111

B3  Eastern Philippines Subduction Zone unit sources. 123

B4  Kamchatka–Bering Subduction Zone unit sources. 125

B5  Kamchatka–Kuril–Japan–Izu–Mariana–Yap Subduction Zone

unit sources. 127

B6  Manus–Oceanic Convergent Boundary Subduction Zone unit

sources. 135

B7  New Guinea Subduction Zone unit sources. 137

B8  New Zealand–Kermadec–Tonga Subduction Zone unit sources. 139

B9  New Britain–Solomons–Vanuatu Subduction Zone unit sources. 143

B10New Zealand–Puysegur Subduction Zone unit sources. 147

B11Ryukyu–Kyushu–Nankai Subduction Zone unit sources. 149

C1 Response of the Point Reyes forecast model to synthetic scenario 

KISZ 1–10 (α=25). Maximum sea surface elevation for A, B, and C

grids. Sea surface elevation time series at the C-grid warning point. 154

C2 Response of the Point Reyes forecast model to synthetic scenario 

KISZ 22–31 (α=25). Maximum sea surface elevation for A, B, and C

grids. Sea surface elevation time series at the C-grid warning point. 155

C3 Response of the Point Reyes forecast model to synthetic scenario

ACSZ 56–65 (α=25). Maximum sea surface elevation for A, B, and C

grids. Sea surface elevation time series at the C-grid warning point. 156

C4 Response of the Point Reyes forecast model to synthetic scenario

CSSZ 89–98 (α=25). Maximum sea surface elevation for A, B, and C

grids. Sea surface elevation time series at the C-grid warning point. 157

C5 Response of the Point Reyes forecast model to synthetic scenario

NTSZ 30–39 (α=25). Maximum sea surface elevation for A, B, and C

grids. Sea surface elevation time series at the C-grid warning point. 158

C6 Response of the Point Reyes forecast model to the 11 March 2011

Tohoku (Honshu) tsunami. Maximum sea surface elevation for

A, B, and C grids. Sea surface elevation time series at the C-grid

warning point. 159

viii Contents
List of Tables

1 Source characterization for historical tsunami events employed in Point

Reyes model testing. (a) The standard set for Pacific Ocean models;

(b) supplementary historical tsunami events for forecast model testing. 6

2 The main features of the San Francisco digital elevation model, which

includes Point Reyes. 11

3 Tidal characteristics of the Point Reyes tide gauge. 13

4 Specific of the reference and forecast model grids employed for Point

Reyes, California. 14

5 Grid file names and grid-related parameters for Point Reyes. 15

6 Synthetic tsunami events employed in Point Reyes model testing. 18

7 Mega-tsunami scenario impacts, represented by flooding and

maximum amplitude at several sites within the model domain. 30

B1 Earthquake parameters for Aleutian–Alaska–Cascadia Subduction

Zone unit sources. 106

B2 Earthquake parameters for Central and South America Subduction

Zone unit sources. 112

B3 Earthquake parameters for Eastern Philippines Subduction Zone unit

sources. 124

B4 Earthquake parameters for Kamchatka-Bering Subduction Zone unit

sources. 126

B5 Earthquake parameters for Kamchatka-Kuril-Japan-Izu-Mariana-Yap

Subduction Zone unit sources. 128

B6 Earthquake parameters for Manus–Oceanic Convergent Boundary

Subduction Zone unit sources. 136

B7 Earthquake parameters for New Guinea Subduction Zone unit

sources. 138

B8 Earthquake parameters for New Zealand–Kermadec–Tonga

Subduction Zone unit sources. 140

B9 Earthquake parameters for New Britain–Solomons–Vanuatu

Subduction Zone unit sources. 144

B10 Earthquake parameters for New Zealand–Puysegur Subduction Zone

unit sources. 148

B11 Earthquake parameters for Ryukyu–Kyushu–Nankai Subduction

Zone unit sources. 150

Contents ix 
C1 Maximum and minimum amplitudes (cm) at the Point Reyes, 

California warning point for synthetic and historical events tested

using SIFT 3.2 and obtained during development. 153

x Contents
Foreword

SEVERAL PACIFIC OCEAN BASIN tsunamis have been recognized as a

potential hazard to United States coastal communities since the mid-twentieth

century, when multiple destructive tsunamis caused damage to the states of

Hawaii, Alaska, California, Oregon, and Washington. In response to these events,

the United States, under the auspices of the National Oceanic and Atmospheric 

Administration (NOAA), established the Pacific and Alaska Tsunami Warning

Centers, dedicated to protecting United States interests from the threat posed by

tsunamis. NOAA also created a tsunami research program at the Pacific Marine

Environmental Laboratory (PMEL) to develop improved warning products.

The scale of destruction and unprecedented loss of life following the December 2004

Sumatra tsunami served as the catalyst to refocus efforts in the United States 

on reducing tsunami vulnerability of coastal communities, and on 20 December

2006, the United States Congress passed the “Tsunami Warning and Education

Act” under which education and warning activities were thereafter specified and

mandated. A “tsunami forecasting capability based on models and measurements,

including tsunami inundation models and maps” is a central component for the 

protection of United States coastlines from the threat posed by tsunamis. The forecasting capability for each community described in the PMEL Tsunami Forecast

Series is the result of collaboration between the National Oceanic and Atmospheric

Administration office of Oceanic and Atmospheric Research, National Weather

Service, National Ocean Service, National Environmental Satellite, Data, and

Information Service, the University of Washington’s Joint Institute for the Study 

of the Atmosphere and Ocean, National Science Foundation, and United States

Geological Survey.

NOAA Center for Tsunami Research

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California xi 

PMEL Tsunami Forecast Series: Vol. 6

A Tsunami Forecast Model for Point Reyes, California

M.C. Spillane1,2

Abstract. Operational tsunami forecasting by NOAA’s Tsunami Warning Centers

relies on the detection of tsunami wave trains in the open ocean, inversion of these

data (telemetered via satellite) to quantify their source characteristics, and real-time

modeling of the impact on threatened coastal communities. The latter phase of the process 

involves, for each such community, a pre-tested forecast model capable of predicting the

impact, in terms of inundation and dangerous inshore currents, with sufficient resolution and within the time constraints appropriate to an emergency response. To achieve

this goal, considerable advance effort is required to tune each forecast model to the

specific bathymetry and topography, both natural and manmade, of the impact area,

and to validate the model’s performance with a broad set of tsunami sources. Where

possible, the validation runs should replicate observed responses to historical events,

but the sparse instrumental record of these rare but occasionally devastating occurrences dictates that comprehensive testing also include a suite of scenarios that represent potential future events.

During the forecast model design phase, and in research mode outside the pressures of

an emergency situation, more detailed and slower-running models can be investigated.

These models, referred to as reference models, represent the most credible numerical

representation of tsunami response for a study region, using the most detailed bathymetry available and without the run-time constraint of operational use. Once a reference

model has been developed, the process of forecast model design is to determine where

efficiencies can be gained by reducing the grid resolution and increasing the model time

step, while still adequately representing the salient features of the full solution.

This report documents the reference and forecast model development for Point Reyes, 

California, and its vicinity, comprising much of western Marin County. The Point Reyes

headland juts out into the Pacific Ocean and its lighthouse is a prominent navigation landmark northwest of the entrance to San Francisco Bay. A tide gauge within

Drakes Bay, in the lee of the headland, provides observations for model validation from

numerous historical tsunamis. While much of the study region lies within a National

Seashore area, limiting the population and waterfront infrastructure, there are a

number of nearby communities exposed to tsunami impact. Beaches and other natural

amenities and the mild climate foster extensive recreational use, and there is a clear 

need for emergency preparedness. This report addresses the tsunami aspects of the 

natural hazard spectrum.

1 Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of 

Washington, Seattle, WA

2  NOAA/Pacific Marine Environmental Laboratory (PMEL), Seattle, WA

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 1 

1. Background and Objectives

1.1 The setting

Point Reyes, California, lying to the northwest of the entrance to San Francisco

Bay, is a prominent navigational landmark. As illustrated in Figure 1, composed of 

orthographic images from “Marin-Maps” (mmgis.marinmap.org/OrthoGrid/viewer.

htm), the headland is the site of a lighthouse, and, in Drakes Bay in its lee, adjacent to the historic Point Reyes Lifeboat Station is the tide gauge bearing the same

name. All lie within the Point Reyes National Seashore (PRNS), composing most of

west Marin County, which is essentially unpopulated and in a natural state, with

the exception of some agricultural activity that was allowed to continue when the

PRNS was established in 1962. As seen in the inset to Figure 1, the San Andreas 

Fault (SAF) strongly delineates the eastern boundary of the region, though it is

submerged in Tomales Bay in the north and Bolinas Lagoon in the south. In the

neck of land between them are the communities of Olema and Point Reyes Station,

which are close to the epicenter of the 1906 San Francisco earthquake. Several

small communities lie on the shores of Tomales Bay (20.4 km in length but with

a mean depth of only 3.1 m; Niemi and Hall, 1996). The entrance is shallow and

constricted. To the south, Bolinas and Stinson Beach, with communities of 1620

and 632 residents, respectively (Census Bureau, 2010), have greater exposure to

damage from tsunami or winter storm waves. Between Stinson Beach and Point

Bonita, the southernmost point of Marin County, lies Muir Beach, a community of

about 310 (Census Bureau, 2010). It is notable, from the tsunami perspective, in

that it reported major runups during the 1946 Unimak and 1964 Alaska events.

North of Tomales Bay is Bodega Bay (population: 1077; Census Bureau, 2010),

whose shores lie both in Marin and Sonoma counties. Apart from the shallow

Bodega Harbor and the communities of Bodega Bay and Doran Beach extending 

onto the spit at its mouth, this area too is sparsely populated. The natural beauty

of the region, with its mild climate and proximity to the San Francisco area and

other urban centers, provides outstanding recreational opportunities resulting in

large numbers of visitors throughout the year.

Normally, in selecting the domain of a tsunami forecast model, the location 

of a tide gauge provides the focus, but in this case, a somewhat larger region is

included to provide forecast capability to population centers and primary recreational assets. Initially it was hoped that a forecast model could cover the entire

region from Bodega Bay to Muir Beach. This proved to be impossible, given the

time constraints on model run time imposed by emergency usage, without an unacceptable reduction in spatial resolution. While the innermost area of study used in 

the reference model does include Tomales Bay and a portion of Bodega Bay, these

are excluded from the forecast model, which focuses on the south and southwest

area of Marin County (http://xenon.colorado.edu/spotlight/). 

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 3 
The University of Southern California Tsunami Research Center conducted a 

comprehensive study of potential tsunami inundation for the entire California coastline. Funded through the California Emergency Management Agency (CalEMA)

by the National Tsunami Hazard Program, the study (Barberopoulou et al., 2011)

has produced a set of inundation maps for emergency planning purposes, accessible online in various forms, including “MyHazards” (myhazards.calema.ca.gov), 

which enables users to acquire information specific to their site of interest. The

CalEMA inundation results are available in GIS form and those specific to the

Point Reyes area are used throughout this report. In addition to underpinning the 

modeling effort, the digital elevation model (DEM) for the San Francisco region,

provided by the National Geophysical Data Center (NGDC), includes a 3-D oblique

view that assists greatly in visualizing the study area. In Figure 2, the CalEMA

inundation information is overlaid with descriptive labels on an extract from the

NGDC image. The full 3-D image is available in the San Francisco DEM Report

(Carignan et al., 2010).

A striking series of aerial photographs (www.californiacoastline.org) shows

that the study region contains both high cliffs (also seen in Figure 3), which limit

potential impact by tsunamis, and broad beaches and shallow coastal inlets that

are more exposed. Queries to the CalEMA My Hazards site show, in addition to

tsunamis, that flooding and earthquakes are hazards to which Bolinas and Stinson

Beach are prone. Available online is a video, “Marin Tsunami” (Loeffler and

Gesell, 2010), produced for the U.S. Geological Survey (USGS) in cooperation with

the Marin County Sheriff’s Office of Emergency Services. In addition to providing

an overview of the comprehensive level of preparedness for tsunami impact on the

communities of Bolinas, Stinson Beach, Dillon Beach/Lawson’s Landing, and the

National Park Service’s popular Limantour Beach, this excellent resource for residents and visitors alike gives insight into the character of the area.

1.2 Natural hazards

Instances of mild tsunami signals are evident in the tide gauge records for Point 

Reyes (established in 1975), and Marin County sites appear several times in the

records compiled by Lander and Lockridge (1989) and their regularly updated

online equivalent, the NGDC Tsunami Hazard Database (Dunbar, 2007; see ngdc.

noaa.gov/hazard/). The historical record first mentions Marin County with a wave

observed at Sausalito, on the north shore of the Golden Gate, from a Chilean event

in 1877. The earliest time series currently available for analysis is a digitized marigram from Sausalito, recorded during the Sanriku event of 1896 and available in

the National Tsunami Warning Center (NTWC) archives. O’Brien (1946) described

a 2.6 m wave above Mean Lower Low Water (MLLW) in Drakes Bay during the 

1946 Unimak tsunami, with a boat washed onto the highway. While Marin County

sites are not explicitly mentioned in connection with the 1952 Kamchatka or 1957

Andreanof events, waves were observed at Bodega Bay and within San Francisco

Bay. During the 1960 Chile event, a 1.5 m runup was reported at Stinson Beach,

and during the 1964 Alaska tsunami, waves were observed at several sites within

Marin County, including Drakes Beach. Time series from several tsunamis are

4 Spillane
available from the Point Reyes tide gauge in recent years, culminating in the major

event east of Japan’s island of Honshu on 11 March 2011 (also referred to as the

Tohoku earthquake). The latter will be discussed extensively in this report.

Combining events impacting northern California with those that have occurred

since the Point Reyes tide gauge was upgraded to 1 min sampling, a total of 27

historical events are available for study. Nineteen of these, listed in Table 1a, are 

among the preferred cases for forecast model testing in the Pacific because their

seafloor deformation is reasonably well known, either from the literature or more

recently derived from direct observation of the wave trains they generated. The

remaining eight, listed in Table 1b, have source characteristics that are less well

known; they are included to expand the geographical coverage or because of their

special relevance to the U.S. West Coast. The Mw 7.2 earthquake north of Cape

Mendocino on 25 April 1992 was a very mild foretaste of a Cascadia Subduction

Zone event, but was registered in marigrams at Arena Cove and Point Reyes.

Others, due to significant noise in the tide gauge, do not produce a clear signal but

shed light on Point Reyes as a reference point for coastal impacts. Figure 4 illustrates the distribution of the 27 historical sources. Those highlighted in red were

employed for intercomparison of the reference and forecast versions of the model.

Direct seismic impact is another natural hazard to which Marin County is

exposed. Its proximity to the rupture zone of the SAF in the San Francisco earthquake of 1906 resulted in significant lateral displacements and some damage in

the inland towns. The lighthouse on the Point Reyes headland suffered only mild

damage. While the SAF enters the ocean at Bolinas, its strike-slip nature reduces

the likelihood of severe tsunami wave generation should ruptures occur in the

immediate vicinity. Submarine landslides or collapse of sections of sea cliff are,

however, a potential local source for tsunami damage. Landslides triggered by

seismic events caused significant loss of life during the 1929 Newfoundland event

and accentuated the 1996 New Guinea tsunami. Landslide-generated tsunami

waves are not currently included in the forecasting system SIFT (Short-term

Inundation Forecasting for Tsunamis), developed at NOAA Center for Tsunami

Research (NCTR) and now in operational use at the U.S. Tsunami Warning

Centers (TWCs), nor are those that are generated meteorologically. However, to

the extent that the waves they produce are detected by the DART® array, some 

warning of their presence may be available.

Another local hazard that has been a frequent cause of damage in the Bolinas–

Stinson Beach area is ocean wave action. Originating locally, or as swell from

distant storms, such waves in the winters of 1977–78 and 1982–83 caused the

loss of several beachfront homes. Another impact of ocean waves, of relevance to

tsunami detection and modeling, is in the noise they produce in the tide gauge 

records. Although the Point Reyes tide gauge is in the lee of the headland, excessive wave action and resonance can mask weak tsunami signals.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 5 
Table 1: Source characterization for historical tsunami events employed for Point Reyes, California, model testing. Events in bold text were used to compare

the reference and forecast model versions. Sources identified as “preliminary” or “ad hoc” may not be identically defined in other forecast model reports. (a)The standard set for Pacific Ocean models; and (b) supplementary historical tsunami events employed for forecast model testing.

Earthquake / Seismic Model

Event

USGS 

Date Time (UTC) 

Epicenter

CMT 

Date Time (UTC) 

Centroid

Magnitude 

Mw

Tsunami 

Magnitude

Subduction

Zone Tsunami Source (Reference/Derivation)

(a) Standard set for Pacific Ocean models:

1946 Unimak 01 Apr 12:28:56

52.75oN 163.50oW

Not Available 8.5 8.5 ACSZ 7.5 × B23 + 19.7 × B24 + 3.7 × B25

(López and Okal, 2006)

1952 Kamchatka 04 Nov 16:58:26.0

52.76°N 160.06°E

Not Available 9.0 9.0 KISZ 19.71 × (A4 + Y4 + Z4 + A5 + Y5 + Z5 + A6 + Y6 + Z6)

[ad hoc]

1957 Andreanof 09 Mar 14:22:31

51.56oN 175.39oW

Not Available 8.6 8.7 ACSZ 31.4 × A15 + 10.6 × A16 + 12.2 × A17 [preliminary]

1960 Chile 22 May 19:11:14

38.29°S 73.05°W

Not Available 9.5 9.5 CSSZ 125 × (A93 + B93 + Z93 + A94 + B94 + Z94 + A95 + B95)

(Kanamori and Cipar, 1974)

1964 Alaska 28 Mar 03:36:00

61.02°N 147.65°W

Not Available 9.2 8.9 ACSZ 15.4 × A34 + 18.3 × B34 + 48.3 × Z34 +19.4 × A35 +

15.1 × B35 (Tang et al. 2006, 2009)

1994 East Kuril 04 Oct 13:22:58

43.73oN 147.321oE

04 Oct 13:23:28.5

43.60oN 147.63oE

8.3 8.1 KISZ 9.0 × A20 [ad hoc]

1996 Andreanof 10 Jun 04:03:35

51.56oN 175.39oW

10 Jun 04:04:03.4

51.10oN 177.410oW

7.9 7.8 ACSZ 2.40 × A15 + 0.80 × B16 [preliminary]

2001 Peru 23 Jun 20:33:14

16.265oS 73.641oW

23 Jun 20:34:23.3

17.28oS 72.71oW

8.4 8.2 CSSZ 5.7 × A15 + 2.9 × B16 + 1.98 × A16 [preliminary]

2003 Hokkaido 25 Sep 19:50:06

41.775oN 143.904oE

25 Sep 19:50:38.2

42.21oN 143.84oE

8.3 8.3 KISZ 3.95 × (A22 + B22 + A23 + B23) [ad hoc]

2003 Rat Island 17 Nov 06:43:07

51.13oN 178.74oE

17 Nov 06:43:31.0

51.14oN 177.86oE

7.7 7.8 ACSZ 2.81 × B11 [real-time]

2006 Tonga 03 May 15:26:39

20.13°S 174.161°W

03 May 15:27:03.7

20.39°S 173.47°W

8.0 8.0 NTSZ 6.6 × b29 [ad hoc]

2006 Kuril 15 Nov 11:14:16

46.607oN 153.230oE

15 Nov 11:15:08

46.71oN 154.33oE

8.3 8.1 KISZ 4.0 × A12 + 0.5 × B12 + 2.0 × A13 + 1.5 × B13

[real-time]

2007 Kuril 13 Jan 04:23:20

46.272oN 154.455oE

13 Jan 04:23:48.1

46.17oN 154.80oE

8.1 7.9 KISZ -3.64 × B13 [real-time]

2007 Solomon 01 Apr 20:39:56

8.481oS 156.978oE

01 Apr 20:40:38.9

7.76oS 156.34oE

8.1 8.2 NVSZ 12.0 × B10 [preliminary]

2007 Peru 15 Aug 23:40:57

13.354oS 76.509oW

15 Aug 23:41:57.9

13.73oS 77.04oW

8.0 8.1 CSSZ 0.9 × A61 + 1.25 × B61 + 5.6 × A62 + 6.97 × B62 +

3.5 × Z62 [preliminary]

6 Spillane
Table 1: Continued.

Earthquake / Seismic Model

Event

USGS 

Date Time (UTC) 

Epicenter

CMT 

Date Time (UTC) 

Centroid

Magnitude 

Mw

Tsunami 

Magnitude

Subduction

Zone Tsunami Source (Reference/Derivation)

(a) Standard set for Pacific Ocean models, continued:

2007 Chile 14 Nov 15:40:50

22.204oS 69.869oW

14 Nov 15:41:11.2

22.64oS 70.62oW

7.7 7.6 CSSZ 1.65 × Z73 [real-time]

2009 Samoa 29 Sep 17:48:10

15.509oS 172.034oW

29 Sep 17:48:26.8

15.13oS 171.97oW

8.1 8.1 NTSZ 3.96 × A34 + 3.96 × B34 [real-time]

2010 Chile 27 Feb 06:34:14

35.909°S 72.733°W

27 Feb 06:35:15.4

35.95oS 73.15oW

8.8 8.8 CSSZ 17.24 × A88 + 8.82 × A90 + 11.84 × B88 + 18.39 × B89 +

16.75 × B90 + 20.78 × Z88 + 7.06 × Z90 [real-time]

2011 Honshu 11 Mar 05:46:24

38.297°N 142.372°E

11 Mar 05:46:23

38.486°N 142.597°E

9.0 9.0 KISZ 4.66 × B24 + 12.23 × B25 + 26.31 × A26 + 21.27 × B26 +

22.75 × A27 + 4.98 × B27 (Tang et al., 2012) [real-time]

(b) Supplementary historical tsunami events employed for forecast model testing:

1896 Sanriku 15 Jun 10:33:00

39.5oN 144.0oE

7.6 7.6 KISZ b25 × 1.413 [ad hoc]

1992 Mendocino 25 Apr 18:06:04

40.368oN 124.316oW

25 Apr 18:06:11.8

38.56oN 123.31oW

7.2 7.2 ACSZ a65 × 0.355 or b65 × 0.355 [ad hoc]

1995 Chile 30 Jul 05:11:24

23.340oS 70.294oW

30 Jul 05:11:56.9

24.17oS 70.74oW

8.0 8.0 CSSZ 2.812 × (a75 + b75) [ad hoc]

1995 Kuril 03 Dec 18:01:09

44.663oN 149.300oE

03 Dec 18:01:36.1

44.82oN 150.17oE

7.9 7.9 KISZ 1.991 × (a17 + z17) [ad hoc]

1996 Irian Jaya 17 Feb 05:59:31

0.891oS 136.952oE

17 Feb 06:00:02.8

0.67oS 136.62oE

8.2 8.2 NGSZ 2.7984 × (a9 + b9 + a10 + b10) [ad hoc]

2009 Papua NG 03 Jan 19:43:51

0.414oS 132.885oE

03 Jan 19:44:09.0

0.38oS 132.83oE

7.6 7.6 NGSZ 0.7046 × (b13 + b14) [ad hoc]

2009 Kuril 15 Jan 17:49:39

46.857oN 155.154oE

15 Jan 17:49:48.3

46.97oN 155.39oE

7.4 7.4 KISZ b12 x 0.7063 [ad hoc]

2009

Vanuatu/

07 Oct 22:03:15

13.052oS 166.187oE

07 Oct 22:03:28.9

12.59oS 166.27oE

7.6 7.6 NVSZ 1.2 × B24 + 0.26 × A23

followed after 15 minutes by

Santa Cruz 07 Oct 22:18:26

12.554oS 166.320oE

07 Oct 22:19:15.3

11.86oS 166.01oE

7.8 7.9 NVSZ 2.6 × B23 + 0.9 × A23 [preliminary]

(Yong Wei, personal communication)

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 7 
1.3 Tsunami warning and risk assessment

The forecast model development described here will permit Point Reyes to be incorporated into the tsunami forecasting system, SIFT. The system has had considerable success in accurately forecasting the impact of both moderate and severe

tsunami events in recent years, and in the following section, the methodology that

permits such forecasts is discussed as prelude to a description of forecast model 

development for Point Reyes. With the model in hand, validated with historical

events and with its stability verified by extensive testing against extreme scenarios,

real-time forecasts will be available to inform local emergency response. Additionally, the synthetic scenarios investigated during model development and reported 

here provide an initial tsunami risk assessment, as described in Section 4.

8 Spillane
2. Forecast Methodology

2.1 The tsunami model

In operational use, NOAA’s tsunami forecast model is used to extend a precomputed 

deepwater solution into the shallows, and onshore as inundation, if appropriate.

The model consists of a set of three nested grids, named A (outermost, with coarse

resolution), B (intermediate), and C (innermost). The latter provides fine resolution that, in a real-time application of the MOST (Method of Splitting Tsunami)

model (Titov and González, 1997; Titov and Synolakis, 1998), permits forecasts

at spatial scales (as little as a few tens of meters) relevant to local emergency

management. The validity of the MOST model applied in this manner and the 

operational effectiveness of the forecast system built around it have been demonstrated during unplanned tests in the Pacific basin, triggered by several mild to

moderate tsunami events in the years since the 2004 Indian Ocean disaster (Wei et 

al., 2008) and during the severe 2011 Tohoku/Honshu tsunami (hereafter referred

to in this report as the 2011 Honshu tsunami). Successful hindcasting of observed

historic events, even mild ones, during forecast model development lends credence 

to an ability to accurately forecast the impact of future events. Such validation of

tsunami modeling procedures is documented in other volumes of this series. Before

proceeding to a description of the forecast model development for Point Reyes, California, it is useful to describe the steps in the overall forecast process.

2.2 NOAA’s tsunami forecast system

Operational tsunami forecasts are generated at Tsunami Warning Centers, staffed 

continuously around the clock in Alaska and Hawaii, using the SIFT tool, developed at NCTR. The semi-automated process facilitates the steps by which TWC

operators assimilate data from an appropriate subset of DART tsunami sensors,

“invert” the data to determine the linear combination of precomputed propagation

solutions that best match the observations, then initiate a set of forecast model

runs if coastal communities are threatened, or, if warranted, cancel the warning.

Steps in the process are as follows:

• When a submarine earthquake occurs, the global network of seismometers

registers it. Based on the epicenter, the unit sources in the propagation

database (Gica et al., 2008) that are most likely to be involved in the event

and the DART array elements (Spillane et al., 2008) best placed to detect

the waves’ passage are identified. TWC operators can trigger DARTs into

rapid sampling mode in the event that this did not occur automatically in 

response to the seismic signal.

• There is now an unavoidable delay while the tsunami waves are in transit to

the DARTs. At least a quarter of a cycle of the first wave in the train must

be sampled before moving to the “inversion” step.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 9 
• When sufficient data have accumulated at one or more DARTs, the observed

time series are compared with the model series from the candidate unit

sources. Since the latter are precomputed (using the MOST code), and 

the dynamics of tsunami waves in deep water are linear, a least squares

approach can quickly identify the unit sources (and the appropriate scale

factors for each) that best fit the observations. The inversion methodology is

described by Percival et al. (2011).

• Drawing again on the propagation database, the scale factors are applied to

produce a composite basin-wide solution with which to identify the coastal

regions most threatened by the radiating waves.

• It is at this point that one or more forecast models are run. The composite 

propagation solution is employed as the boundary condition to the outermost

(A-grid) domain of a nested set of three real-time MOST model grids that

telescope with increasingly fine scale to the community of concern. A-grid

results provide boundary conditions to the B grid, which, in turn, forces the

innermost C grid. Nonlinear processes, including inundation, are modeled 

so that, relying on the validation procedures during model development, 

credible forecasts of the current event are available.

• Each forecast model provides quantitative and graphic forecast products

with which to inform the emergency response or to serve as the basis for

canceling or reducing the warnings. Unless the tsunami source is local,

the forecast is generally available before the waves arrive. Even when lead

time cannot be provided, the several hour duration of a significant event (in

which the first wave may not be the most damaging) gives added value to

the multi-hour forecasts provided.

Because multiple communities may be at risk, it may be necessary to run,

simultaneously or in a prioritized manner, multiple forecast models. Each must be

optimized to run efficiently in as little time as possible. The current target is that

an operational forecast model should be capable of simulating 4 hr of real time

within about 10 min of CPU time on a fast workstation computer.

10 Spillane
3. Model Development

3.1 Digital elevation models

Water depth determines local tsunami wave speed, and subaerial topography determines the extent to which tsunami waves inundate the land. Thus, a prerequisite

for credible tsunami modeling is the availability of accurate gridded bathymetric

and topographic datasets, termed digital elevation models, or DEMs. Given their

expertise in this area and the number of coastal communities needing tsunami

forecast capability, NCTR relies heavily on the NGDC to provide the DEMs needed.

In the case of Point Reyes, California, a subregion of the San Francisco DEM is

employed. This DEM, a composite of multiple data sources merged and converted

to a common datum of mean high water (MHW), was produced and documented

by Carignan et al. (2010). MHW is employed as the “zero level” in all forecast

models. The MOST model does not include tidal fluctuations, and, since a tsunami

may arrive at any stage of the tide, it is best to employ a “worst-case” approach

by assuming high tide when forecasting inundation. For some forecast models,

grounding of vessels and the strong and rapidly varying currents often associated 

with even mild tsunamis are of concern. For Point Reyes, which lacks a marina

and shoreline infrastructure, low water impacts are less important.

The Point Reyes subregion of the San Francisco DEM is illustrated in Figure 2; 

its salient features listed in Table 2 are reproduced from DEM documentation

(Carignan et al., 2010). The NGDC report thoroughly describes the data sources

and methods employed in constructing the DEM. With 1/3 arc sec (10 m) resolution,

the DEM provides the basis for the B and C grids for both reference and forecast

model usage. NCTR maintains an atlas of lower-resolution gridded bathymetries

that can be used for the A grids, as described later. All of the DEMs employed were

verified for consistency with charts, satellite imagery, and other datasets during

the course of MOST grid development. 

Grid Area San Francisco, California

Coverage Area 123.30° to 121.85°W; 37.32° to 38.48°N

Coordinate System Geographical decimal degrees

Horizontal Datum World Geodetic System 1984 (WGS84)

Vertical Datum Mean High Water (MHW)

Vertical Units Meters

Cell Size 1/3 arc sec

Grid Format ESRI Arc ASCII grid

Version Employed 24 February 2011 update

Table 2: The main features of the San Francisco digital elevation model (DEM), which

includes Point Reyes, California.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 11 
The elevations and depths used in the development of this forecast model were

based on the DEM provided by the NGDC; the author considers it to be a good

representation of the local topography and bathymetry. As new DEMs become

available, forecast models will be updated and report updates will be posted at

nctr.pmel.noaa.gov/forecast_reports/.

3.2 Tides and sea level variation

The history of tidal observation at Point Reyes dates back only to 1975. Tide station

9415020 is located near the end of a pier projecting into Drakes Bay, just west of

the historic Lifeboat Station. The pilings raise the deck well above sea level and do

not impede water movement. The instrumentation was upgraded in 2006 to include

a tsunami-capable gauge sampling at 1 min intervals (and on demand at 15 sec

intervals); some earlier data were sampled at 6 min intervals, and several historical events are only available as marigrams on microfiche. An ongoing project at

NGDC will be to digitize the more critical images in this archive; a few are available in digitized form in the NTWC archives.

Station characteristics for 9415020 are provided in Table 3, based on the

wealth of online tidal information available at NOAA’s CO-OPS (Center for Operational Oceanographic Products and Services) website, tidesandcurrents.noaa.

gov. Note the sizeable diurnal range of about 1.7 m and, while the long-term rate

of change in sea level is low (compared to more tectonically active areas), there is

substantial seasonal, interannual, and short-term variability.

An analysis of the 11 March 2011 Honshu event in the Point Reyes model is

given in Section 4.3, with time series data extracted from the CO-OPS website to

illustrate patterns of inundation. In a several hour section of 1 min data, the signature of an arriving tsunami is generally a burst of higher-frequency energy with a

sudden onset. However, during winter months in particular, similar bursts unrelated to tsunami activity are quite common. In January 2011, for example, several

occurred, one of which is illustrated in Figure 5. The tidal signal has been removed

with a Butterworth band-pass filter with cutoff periods at 5 and 120 min. (This

filter is used throughout the report to pre-process tide gauge records for comparison

with model prediction.) The lower panel of Figure 5 is the spectral wave energy at

hourly intervals from NDBC buoy 46026, 18 nm west of San Francisco. There is a

clear correlation between enhanced swell at this site and the detided residuals in

Drakes Bay, suggesting that surface waves can excite a coastal response. For the

example shown, the amplitude of this noise (perhaps 10–20 cm) would likely obscure

a mild tsunamis signature were one to arrive during such an episode. Deviations

(or residuals) from the astronomically predicted tide can be several centimeters and

the variability strong. In particular, the highest water level reported for the Point

Reyes tide gauge is 1.05 m above MHW (6 February 1998), so the use of MHW as

the zero level of modeled sea level may underestimate the truly worst case. While

the simultaneous arrival of the crest of a large tsunami at high tide during a storm 

surge has low probability, a feature of the simulated events reported below is that

sustained oscillations at a resonant period may extend the duration of the threat. 

This effect is notorious at Crescent City, California, which is frequently the most

heavily impacted U.S. West Coast location for remote events.

12 Spillane
3.3 The CFL condition and other considerations for grid design

Water depth-dependent wave speed, in conjunction with the spacing of the spatial

grid representation, places an upper limit on the time step permissible for stable

numerical solutions employing an explicit scheme. This is the CFL (Courant-Friedrichs-Levy) limit, which requires careful consideration when the grids employed

for a reference or forecast model are being designed. Finer-scale spatial grids, or

greater water depths, require shorter time steps, thereby increasing the amount

of computation required to simulate a specific real-time interval.

Another feature of the application of gridded numerical solutions to the tsunami 

wave problem is the shortening that the wave train encounters in moving from

deep water onto the shelf. In deep water, a grid spacing of 4 arc min (of latitude and

longitude, corresponding to ~7 km) is normally used to represent propagating wave

trains with a typical wavelength of the order of a few hundred kilometers. The

stored results of such propagation model runs are typically decimated by a factor

of 4, resulting in a database of ~30 km spacing (and 1 min temporal sampling) with

which to generate the boundary conditions for the outermost (A grid) of the nested

grids in a model solution. The extraction of the boundary conditions (of wave height

and the two horizontal velocity components) is achieved by linear interpolation in

space and time. To provide realistic interpolated values, the stored fields for these

variables must be smoothly varying and have adequate sampling in space and time

to resolve their structure. This necessitates the placement of the outer boundary

of the forecast model domain well offshore. The presence of the Mendocino Escarpment is another incentive to do so, to ensure that its role in topographic steering of 

trans-Pacific wave trains is adequately represented.

Point Reyes, California: Station 9415020 (37°59.7 ́N, 122°58.6 ́W)

Tidal Datum and Range Values (Epoch 1983–2001)

MHHW (Mean Higher High Water) 2.964 m

Great Diurnal

Range 

1.758 m

MHW (Mean High Water) 2.760 m

Mean Range 

1.193 m MSL (Mean Sea Level) 2.152 m

MLW (Mean Low Water) 1.567 m

MLLW (Mean Lower Low Water) 1.206 m

Sea Level Trends and Cycles

Long-term Sea Level Trend Increasing 1.39 ± 1.05 mm/yr

Seasonal Cycle Range Min. –90 mm (April); Max. +60 mm (September)

Interannual Variation (from 1980) Min. –19 mm (1989); Max. +22 mm (1997)

Extremes to Date (October 2014)

Maximum 3.810 m on 6 February 1998

Minimum 0.387 m on 19 January 1988

Table 3: Tidal characteristics of the Point Reyes tide gauge.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 13 
3.4 Specifics of the model grids

After several rounds of experimentation, the extents and resolutions of the nested 

grids were chosen; these are illustrated in Figures 6–8 and details are provided 

in Tables 4 and 5. The reference model grid extents were set early in the process

when the objective was to provide forecast results from Bodega Bay to Muir Beach,

but they have further value in ensuring adequate representation of waves entering

the domain from remote sources. The reference model grids are displayed in 

Figure 7; in the A- and B-grid panels, rectangles show the nested grid domain

within. In the case of the reference model C-grid panel, the reduced extent of the

equivalent forecast model grid is indicated. Figure 8 depicts the nested grids of 

the forecast model itself. The main focus of the forecast model, and of this report, 

is on the southwestern and southern portions of Marin County. Some mention of

the northern portion will be made as appropriate but with the exception of some

results that can be derived from the A grid, comprehensive forecasts for Bodega

Bay will require a dedicated model.

Both C grids lie entirely within the NGDC-provided DEM; A and B grids

include bathymetry and topography from other DEM datasets available at NCTR.

Some smoothing and editing were necessary to eliminate erroneous points or grid

features that tend to cause model instability. For example, “point” islands, where

an isolated grid cell stands above water, are eliminated, as are narrow channels

or inlets one grid-unit wide; these tend to resonate in the numerical solution.

Large depth changes between adjacent grid cells can also cause numerical problems; customized tools (such as “bathcorr”) are available to correct many of these

grid defects. An additional constraint on the bathymetry (Elena Tolkova, personal

communication), which identifies excessive depth changes in the discrete representation, was applied.

Reference Model for Point Reyes, California

Minimum offshore depth: 1.5 m; Water depth for dry land: 0.1 m; Friction coefficient (n2): 0.0009;

CPU time for a 4-hr simulation: 305 min

Grid Zonal Extent Meridional Extent Resolution Grid Points

A 128.000°W 121.500°W 36.000°N 42.500°N 30" × 30" 781 × 781

B 123.300°W 122.100°W 37.475°N 38.475°N 4" × 3" 1081 × 1201

C 123.150°W 122.533°W 37.825°N 38.350°N 4/3" × 1" 1666 × 1891

Forecast Model for Point Reyes, California

Minimum offshore depth: 2.5 m; Water depth for dry land: 0.1 m; Friction coefficient (n2): 0.0009;

CPU time for a 4-hr simulation: 8 min

Grid Zonal Extent Meridional Extent Resolution Grid Points

A 125.000°W 122.000°W 37.000°N 39.000°N 60" × 60" 181 × 121

B 123.300°W 122.100°W 37.550°N 38.475°N 18" × 15" 241 × 233

C 123.130°W 122.533°W 37.825°N 38.100°N 4" × 3" 538 × 331

CPU times for a 4-hr simulation are based on use of a single Intel® Xeon® E5670 2.93GHz processor.

Table 4: Specifics of the reference and forecast model grids employed for Point Reyes, California. For

the paired values in the resolution and grid points columns, the zonal (east to west) value is listed first,

followed by the meridional (north to south).

14 Spillane
Details of the model grids are provided in Tables 4 and 5. The latter lists 

the maximum depth, the CFL time step requirement that must not be exceeded,

and the actual time steps chosen for the reference and forecast model runs. Since 

the numerical solutions in the three grids proceed simultaneously in the current 

version of MOST employed by SIFT, there is a requirement that the A- and B-grid

time steps be integer multiples of the (innermost) C-grid time step, in addition

to satisfying the appropriate CFL requirement. For both reference and forecast

models, the CFL requirement of the C grid was the most stringent. The values

chosen are shown in Table 5 and are such that an integer multiple of each time 

step (15 × for the forecast model; 50 × for the reference model) is identically 30

sec, the chosen output time interval for both models. When run on an Intel® Xeon®

E5670 2.93 GHz processor, the forecast model produces 4 hr of simulation in 7.46

min, within the desired 10 min value for this metric.

3.5 Model run input and output files

In addition to providing the model grid file names, the appropriate time step, and

A and B grid multiples as provided in the tables above, it is necessary to provide

a number of additional parameters in an input file. These include the Manning

friction coefficient (n), a depth threshold to determine when a grid point becomes

inundated, and the threshold amplitude at the A-grid boundary that will start

the model. An upper limit on wave amplitude is specified in order to terminate

the run if the waves grow beyond reasonable expectation. Usual MOST values are

used: 0.0009 for the squared friction coefficient (n2)and 0.1 m for the inundation

threshold. The latter causes the inundation calculation to be avoided for insignificant water encroachments that are probably below the level of uncertainty in the

topographic data. Inundation can, optionally, be ignored in the A and B grids, as

is the norm in the (non-nested) MOST model runs that generate the propagation

database. When A- and B-grid inundation is excluded, water depths less than a

specified “minimum offshore depth” are treated as land; in effect, a “wall” is placed

at the corresponding isobath. When invoked, a typical value of 1–5 m is applied

as the threshold, although A and B inundation is normally permitted as a way to

gain some knowledge of tsunami impact beyond the scope of the C-grid domain.

Other parameter settings allow decimation of the output in space and/or time. As

noted above, 30 sec output has been the target and output at every spatial node is

preferred. These choices avoid aliasing in the output fields that may be suggestive

of instability (particularly in graphical output), when none, in fact, exists.

Grid File Name

Maximum 

Depth (m)

Minimum 

CFL (s)

Model Time 

Step (s)

Water 

Cells

A PtReyesCA_RM_A 5002 3.350 1.2 (2×) 436,723

PtReyesCA_FM_A 4379 7.137 6.0 (3×) 15,977

B PtReyesCA_RM_B 2166 0.637 0.6 (1×) 664,682

PtReyesCA_FM_B 2114 3.062 2.0 (1×) 26,598

C PtReyesCA_RM_C 98.6 0.995 0.6 1,411,698

PtReyesCA_FM_C 94.7 3.045 2.0 103,086

Table 5: Grid file names and grid-related parameters for Point Reyes, California. The time steps

for the A and B grids must be integer multiples of the basic time step chosen for the C grid.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 15 
Finally, the input file (supplied in Appendix A) provides options that control the

output produced. Output of the three variables—wave amplitude, zonal (positive to

the east) velocity, and meridional (positive to the north) velocity—can be written

(in netCDF format) for any combination of grids A, B, and C. These files can be

very large. A separate file, referred to as a SIFT file, contains the time series of

wave amplitude at each time step at discrete cells of a selected grid. Normally, the

time series at a “reference” or warning point, typically the location of a tide gauge,

is selected to permit validation in the case of future or historical events. As noted 

earlier, several additional sites within the model domain were specified during

development and are discussed in Section 4 of this report. The SIFT file output

also includes the distribution of the overall minimum and maximum wave amplitude and speed in each grid. By contrast with the complete space-time results of a

run, the SIFT file (also netCDF) is very compact.

By default, two additional output files are generated. A “listing” file summarizes run specifications, progress, and performance in terms of run time, as well

as information to determine the reason, should a run not start or terminate early. 

A “restart” file is produced so that a run can be resumed from the time it ended,

either normally or by operator intervention.

The input files described above are specific to the model itself. For an actual

run, the program must be pointed toward the files that contain the boundary conditions of wave amplitude (H) and velocity components (U, V) to be imposed at the

A-grid boundary. Time-varying conditions are generally extracted as a subset of a

basin-wide propagation solution (either a single unit source or several, individually

scaled and linearly combined) that mimics a particular event. These boundaryforcing files typically consist of 24 hr of values (beginning at the time of the earthquake), sampled at 1 min intervals and available on a 16 arc min grid. Occasionally, for more remote seismic sources or when delayed arrival of secondary waves

due to reflections are a concern (as has been seen at Hawaii), the time span of the

propagation run available for forcing is extended beyond one day.

16 Spillane
4. Results and Discussion

Before proceeding to an extensive suite of model runs that explore the threat to

Marin County, California, from various source regions, the stability of the Point

Reyes model is tested in both low and extreme amplitude situations. The former

we refer to as “micro-tsunami” testing, where the boundary forcing is at such a

low level (but not precisely zero) that the response is expected to be negligible.

These tests can be highly valuable in revealing localized instabilities that may

result from undesirable features in the discretized bathymetric representation.

Inlets or channels that are only one grid-cell wide may “ring” or resonate in a nonphysical way in the numerical solution. An instability may not grow large enough

to cause the model to fail but, in a run with typical tsunami amplitudes, may be

masked by actual wave variability.

Forcing by extreme events, which we refer to as “mega-tsunami” events, is

also tested. In addition to the need to test model stability under such circumstances, there is a parameter in the input file that truncates the run if a prescribed

threshold is exceeded. For operational use, the threshold must be set high enough

so that an extreme event run is not unnecessarily terminated. Both tests should

be performed for test sources whose waves enter the model domain from different

directions since, although stable for one set of incoming waves, an instability may

be encountered for another. The micro- and mega-tsunami testing of the forecast

and reference models is reported in the following subsections. Further evidence

of stability is provided by the extensive set of historical (Sections 4.3–4.6) and

synthetic (Section 4.7) scenarios, aimed at exploring the dependence of impact to

source location and used in independent testing by other members of the NCTR

team prior to the model’s release for operational use.

4.1 The micro-tsunami tests

Three cases (see Table 6) were run representing micro-tsunami sources in the

western Aleutians, the Philippines, and south of Japan (see Figure 10). Based on

sources from the propagation database (Gica et al., 2008), their amplitudes were

scaled down by a factor of 100 so as to mimic a Mw 6.167 / Slip 0.01 m source

rather than the Mw 7.5 / Slip 1 m of a unit source. A number of grid cells in the

B and C grids emerged as potential sources of instability. Generally, these were

minor indentations of the coastline barely resolved by the grids, or narrow channels. The region contains several inlets (called esteros) extending far inland that, 

at a practical level of spatial resolution, proved difficult to accommodate. Among

these are the upper reaches of the multiple arms of Drakes Estero and, feeding

into Bodega Bay, Estero Americano and Estero de San Antonio. A limited number

of grid cells in the outermost (A) grid required correction. These were generally

associated with non-physical features in the topographic database, such as a track

of ship-based soundings that were improperly merged with other data sources.

After an iterative process of grid correction and retesting using these sources, both

the reference and forecast model grids were deemed satisfactory and the testing

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 17 
of extreme and historical events could begin. Figure 9 illustrates a step in the 

process where a deficiency in the reference model grid generated a mild instability

(in the EPSZ B19 micro-tsunami scenario—see Table 6) causing the reference 

model time series at the reference point, initially in close agreement with the forecast model, to develop unrealistic, high-frequency oscillations. Though still generally tracking the forecast model result, and not growing without bound, the feature

could behave erratically in simulating real events. Modification of the reference

model bathymetry eliminated the problem, as seen in the lower panel of Figure 9, 

and micro-tsunami tests involving other sources (RNSZ B14 and ACSZ B6) did not

reveal other issues.

Scenario Source Zone Tsunami Source

α

[m]

Mega-tsunami (Mw 9.3) Scenario 

KISZ 1–10 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A1–10, B1–10 25

KISZ 22–31 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A22–31, B22–31 25

KISZ 32–41 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A32–41, B32–41 25

KISZ 56–65 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A56–65, B56–65 25

ACSZ 6–15 Aleutian-Alaska-Cascadia A6–15, B6–15 25

ACSZ 16–25 Aleutian-Alaska-Cascadia A16–25, B16–25 25

ACSZ 22–31 Aleutian-Alaska-Cascadia A22–31, B22–31 25

ACSZ 50–59 Aleutian-Alaska-Cascadia A50–59, B50–59 25

ACSZ 56–65 Aleutian-Alaska-Cascadia A56–65, B56–65 25

CSSZ 1–10 Central and South America A1–10, B1–10 25

CSSZ 37–46 Central and South America A37–46, B37–46 25

CSSZ 89–98 Central and South America A89–98, B89–98 25

CSSZ 102–111 Central and South America A102–111, B102–111 25

NTSZ 30–39 New Zealand-Kermadec-Tonga A30–39, B30–39 25

NVSZ 28–37 New Britain-Solomons-Vanuatu A28–37, B28–37 25

MOSZ 1–10 Manus-Oceanic Convergent Boundary A1–10, B1–10 25

NGSZ 3–12 North New Guinea A3–12, B3–12 25

EPSZ 6–15 East Philippines A6–15, B6–15 25

RNSZ 12–21 Ryukyu-Kyushu-Nankai A12–21, B12–21 25

Mw 7.5 Scenario

NTSZ 36 New Zealand-Kermadec-Tonga B36 1

Micro-tsunami (Mw 6.5) Scenario

EPSZ B19 East Philippines B19 0.01

RNSZ B14 Ryukyu-Kyushu-Nankai B14 0.01

ACSZ B6 Aleutian-Alaska-Cascadia B6 0.01

Table 6: Synthetic tsunami events employed in Point Reyes, California, model testing. The reference 

and forecast model solutions of those shown in bold text were intercompared extensively.

18 Spillane
4.2

The mega-tsunami tests

The record of tsunami impact on the northern California coast discussed later 

reveals that sources around the entire periphery of the Pacific can be felt. Indeed,

the catastrophic Indian Ocean tsunami of 2004 was detectable at Point Reyes, as

it was throughout the global ocean. A broad suite of 19 extreme events (so-called

mega-tsunamis) are part of the NCTR protocol for the testing of Pacific basin forecast models. These are listed in Table 6, and their locations are included in Figure 

10. To simulate each mega-tsunami source, 10 A–B pairs of unit sources are used,

with an evenly distributed slip of 25 m. As described by Gica et al. (2008), each

unit source represents a 100 × 50 km area of the fault surface, with the long axis

parallel to the plate boundary. Row B is shallowest, sloping from a nominal depth

of 5 km (unless a depth estimate has been provided by the USGS based on the

earthquake catalogs), row A is deeper, followed by rows Z, Y, X, etc. where appropriate. Thus, the mega-tsunami event sources represent 1000 km long ruptures

with a width of 100 km; the corresponding magnitude is Mw 9.3.

Discussion of the entire set in greater detail is provided (Section 4.7) once the 

validity of the forecast model has been established. Here we focus on a subset

of three synthetic cases, highlighted in Figure 10 and Table 6, to contrast the 

forecast model with the more highly resolved reference model. In Figures 11–13, 

the reference model results (from the subregion spanned by the forecast model)

are shown in the upper panel. The corresponding forecast model results in the

lower panel employ the same scale. Insets are used to show the time series (black

for reference model, red for forecast model) of H, U, and V at the warning point

(the Point Reyes tide gauge). The lagged correlation of H at the reference point is

drawn in the lower inset and illustrates that there is generally only a few minutes

lag between the time series, with the reference model lagging behind the forecast

model. This behavior is repeated in other scenarios investigated in this chapter.

It is a general feature of MOST and is due to the tendency of more finely resolved

features in the bathymetry slowing the progress of long waves, and arises in the

context of model validation using observations.

The agreement between the reference and forecast model results for the three

mega-tsunami events is good, both for the maximum amplitude and speed distributions, the reference point time series, and the discrete “snapshots” of the amplitude and vector velocity fields. The earliest waves show the best agreement; later

in the solution the reference and forecast model results begin to diverge as multiple

reflections with the coastline occur. A qualitative difference between the solutions

is often seen along the straight coastline north of Point Reyes Lighthouse (see

Figures 1 and 2). The straight shoreline, bounded by rocky headlands at the south

and north, supports edge waves that appear most noticeably in the reference model

results almost as a standing wave pattern, but generally do not propagate around

the headland and into Drakes Bay.

It is noticeable that, in all three of the cases shown, the reference model tends to

oscillate longer and have somewhat larger amplitude than does the forecast model

although the two solutions are in close agreement for the first few tsunami waves.

This is likely a physical reality: the more highly resolved bathymetry and coastline

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 19 
of the reference model provides greater scope for nonlinear features or reflected

waves to develop (as, for example, near the rocky headland west of Bodega Bay).

This observation suggests a caveat to operational use of the forecast model: while

accurate portrayal of the early history of an event is to be expected, the duration

of the event and the amplitude of later waves may be underestimated. Tide gauge

data will be needed to verify this conjecture, which is pursued later in this report.

The snapshot comparisons in the lower panels of Figures 11 and 12 are quite

reasonable, illustrating that the solutions match not just at the reference point. It is

worth noting too that, although the ACSZ 56–65 mega-tsunami event represents a

massive Cascadia tsunami, the scale of impact to the Point Reyes area (~3 m) is not

substantially greater than from trans-Pacific locations (KISZ 1–10 off Kamchatka

and NTSZ 30–39 near Samoa.) The Crescent City response to the same synthetic

Cascadia mega-tsunami event exceeds 10 m (Arcas and Uslu, 2010). It would appear

that the energy propagated alongshore to the south, perhaps due to sheltering by

Cape Mendocino, is reduced, and that perhaps the greatest impact to Marin County 

may be associated with source regions elsewhere in the Pacific basin.

In Figure 13, the comparison time was intentionally chosen later in the event

as a counterexample. While the warning point amplitudes and the nearby fields

of the forecast and reference model may be in reasonable agreement, the broader

wave patterns may have substantial phase differences. The comparisons in these

lower panels are restricted to the portion of C-grid area common to both models,

There is a suggestion that the nearshore velocity fields at the north and south forecast model boundaries differ somewhat from the reference model for which these

are internal points.

Before proceeding to validate the model with historical events, one other

synthetic event is standard in the testing protocol: a mild source of Mw 7.5 at

a remote location. A single unit source near Samoa (NTSZ B36, see Figure 10) 

is employed here and its representation by the reference and forecast model are

compared in Figure 14. Such an event results in a response of about 4 cm in Point

Reyes sea level and again, there is excellent agreement between both model representations in the earlier portion of the event.

The results presented above, for a variety of synthetic events, suggest that the

reference and forecast versions of the model are in good agreement. The match is 

particularly good in the early stages of a wave train; later, as reflections and other

interactions with the coastline occur, the solutions may diverge. The next task is to

ascertain whether the models replicate observations from actual tsunami events.

Given the manner in which the MOST model is forced, at its boundary (with wave

amplitudes and currents not available in real observations), it is not possible to validate the model independently. Rather, as described in Section 2.2, the validation 

will rely on the results of an external model, based perhaps on DART observations

or on a description of the tsunami source in the literature. As a result, the success 

of the model in replicating observations within its domain is, in part, dependent

on the adequacy of the forcing employed to represent the actual external wave

field. For historical events preceding the DART array, the unit source representations are based on seismic observations or coastal tide gauge data. Past experience

suggests that, in the far field at least, the propagation solution is not overly sensi20 Spillane
tive to variation in the unit source weights. Nonetheless, imperfections in forecast

model predictions of coastal observations will not necessarily indicate a defect in

the model itself. Neither are the tide gauge observations, available for comparison

with model prediction, perfect. They may include noise from wind wave activity,

possibly amplified by harbor resonances.

4.3 Model validation: The 2011 Honshu tsunami

In addition to its disastrous impact on the coast of Japan, the Honshu tsunami

of 11 March 2011 radiated waves throughout the Pacific basin. Those arriving at

nearby DARTs were of unprecedented amplitude and their signal-to-noise ratios

facilitated accurate and early source characterization. Further afield, the waves

were detectable at all operational DARTs in the basin and, while major damage

was mainly confined to Japan, significant signals were obtained at multiple coastal

tide gauges. Prior to this event, the 2006 Kuril tsunami event was the best available for model validation. For the U.S. West Coast at least, that role has now been

taken by the 2011 Honshu tsunami. The adequacy of the composite propagation

solution can be assessed by comparison with the BPR signals from the West Coast

DARTs. An additional BPR record is available for this purpose: the MARS cabled

observatory in Monterey Canyon included, between July 2010 and November 2011,

a pair of bottom pressure sensors at a depth of about 870 m. One was a typical

BPR, reporting at the standard DART 15 sec recording interval. The other was

an experimental sensor—the “Nano” (Paros et al., 2011)—sampling at 40 Hz with

enhanced sensitivity. For this report, we employ only data from the typical BPR.

The locations of the West Coast BPRs, reporting during the 2011 Honshu event,

are shown in Figure 15. To the left of the locator chart, the actual and simulated propagation model results, interpolated to the BPR locations, are compared.

There is clearly a strong agreement but even for the earliest waves, there are two

points of difference. Firstly, the model “waves” (drawn in black) arrive about eight

minutes early, a difference that is small compared to the transit time of over nine 

hours. Early arrival in the model is typical and is associated with the limited resolution of the basin-wide bathymetry. Finer-scale features in the actual bathymetry

slow down the real wave trains (the red curves). The other feature of the modeled

versus observed comparison is that the model underestimates the observed signal

by about 20% at all locations. In the right-hand panel of Figure 15, the lagged 

and scaled-up versions of the model time series are seen to be in excellent agreement with observations. Since these results are likely the best obtainable with

the current state of the DART array and inversion methodology, less than perfect

agreement between the forecast model and observations is not necessarily indicative of a major defect in the forecast model itself.

With that caveat, we proceed with the model validation. The prime location

for this purpose is the Point Reyes tide gauge itself, the “reference point” for the

current model. Other coastal locations termed “warning points” are of interest to

the TWCs though they may not have their own dedicated forecast model. In its

basic form, SIFT’s coastal forecast for warning points is generated by extrapolating offshore values from the propagation solution to the coast using Green’s law.

Based on simple assumptions, this law indicates that the waves should grow in

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 21 
inverse proportion to the one-fourth power of the depth ratio. The assumption is

crude at best, and it makes sense that, when a forecast model has been run, the

predictions within its domain are likely to be superior to the Green’s law equivalent and should replace them in an enhanced coastal forecast. For the Point Reyes

model, tide gauge observations are available at several points within the domain

and, in the case of the 2011 Honshu event, all of these had detectable signals. The

auxiliary sites are Bolinas, lying within the C grid but within the lagoon and

with only 6 min sampling; San Francisco, Alameda, and Richmond, within San

Francisco Bay and the model B grid, with 1 min sampling; Arena Cove, near the

northern bound of the forecast model A grid, also with 1 min sampling. The results

of the comparison may be seen in Figure 16 where the reference (black) and forecast (red) versions of the model response are compared to the observations (green.)

The model curves have been lagged to facilitate the comparison but, unlike the

20% enhancement needed to bring the propagation results into conformity with

the DART observations (see Figure 15), the amplitude within the forecast model

has not been adjusted. For the first six hours of the event, the agreement between

observation and model is quite gratifying, particularly at Point Reyes itself and at

San Francisco. For Arena Cove, the agreement is limited more to the early waves.

Perhaps as a result of resonance associated with local geometry, the observed

response grows and shifts to a higher frequency than appears in the model signals.

The reference model solution is a better match in amplitude to the observations

from Arena Cove than is the forecast model, whose representation of the geometry

is quite coarse.

The good agreement between the model amplitude and observation at Point

Reyes, particularly for the first wave, is an apparent contradiction of the situation

at the offshore sites. There, as noted above in the discussion of Figure 15, the 

model forcing underestimated the observations by some 20%. The explanation lies

in an unfortunate data loss in the 1 min data stream from the coastal tide gauges 

during the early part of the event. At most sites, the loss was 18 min, 16:03 to 16:20

UTC (slightly longer at San Francisco), as highlighted in yellow in Figure 16. 

During the event, and in the days that followed, 15 sec data were downloaded

from some tide gauges to bridge the gap. At Point Reyes, these supplementary

15 sec data were unavailable prior to 18:19 UTC. A few points from the 6 min data

stream were employed in the bridging and filtering operations that resulted in the

observed Point Reyes time series. Six minute data badly alias the short time scales

of the tsunami waves and, as a result, the apparent close agreement of model

amplitude and observation for the first wave peak is probably fortuitous.

Progressing deeper into San Francisco Bay, at Alameda and Richmond, the

match between the models themselves and the observations is degraded compared

with the better agreement near the entrance. Nonetheless, the agreement is quite

good and shows promise for an improved “coastal forecast” usage of Point Reyes’

forecast model results. Least satisfying, but understandable, is the comparison at

Bolinas. The tide gauge there lies within the mouth of the lagoon, and an adequate

representation of the narrow entrance channel is difficult, particularly in the forecast model. As is common with narrow-mouthed entrances to enclosed regions,

there is a tendency for the model to retain water (red curve in the upper panel of

Figure 16b) where Bolinas Lagoon increasingly does not empty during the “ebb”

22 Spillane
phase of the tsunami wave train. The reference model solution, perhaps as a result

of excessive modifications or inaccurate representation of entrance geometry in

the DEM, seems to resonate far more than the observational record. It is possible,

however, that with its 6 min sampling and placement, the Bolinas tide gauge is

not well suited to tsunami detection. On a positive note, the timing and amplitude

are not grossly dissimilar to the data. The purpose of the forecast model is more to 

predict the impact on the seaward side of the Stinson Beach spit, and, based on the

success at San Francisco, forecasts outside constricted regions of the model domain

are likely to be quite useful for warning purposes.

We now step back in order to verify the agreement between the reference and

forecast model solutions throughout the common portion of the C-grid domain.

In Figure 17, as was done for the purely synthetic scenarios, the solutions are

compared, based on their maximum amplitude and speed fields, and the time series

and lagged correlation at the Point Reyes tide gauge site. The distribution patterns

of the maximum fields are comparable and it is not unexpected, based on the Point

Reyes time series sample, that the reference model should be the greater, with

the mismatch coming perhaps for the later waves. A pointwise (zero lag) correlation distribution (not shown) between reference and forecast model throughout the

forecast model C-grid domain indicates that over 60% of the variance is explained,

except in constricted areas. The lagged correlation inset confirms a phase difference of only a few minutes between the reference and forecast model time series

at the tide gauge. As a further means of comparing the reference and forecast 

model solutions, snapshots of the amplitude and velocity fields are also provided in

Figure 17. A common scale is used for both the reference (upper panel) and forecast (lower panel) model. The agreement is particularly close when the comparison

time (indicated by the green line) is close to the first peak’s arrival at the tide

gauge. Two later sample times are shown in Figures 17d and 17e, illustrating 

that phase differences can increase as the event unfolds.

The analysis of the 2011 Honshu event in the Point Reyes model is concluded

with an examination of the pattern of inundation in Figure 18. For this purpose,

the full reference model C-grid domain is drawn. The model suggests that, had the

waves arrived at or above MHW, both the Limantour Spit and much of Stinson

Beach and the low-lying parts of Bolinas may have been inundated. In fact, as

illustrated in the inset based on the observed water level at the Point Reyes tide

gauge, the waves barely attained MHW. Though the reporting of the impact on

the U.S. may have been somewhat muted, given the gravity of the imagery from

Japan, it appears that on the U.S. West Coast, the main evidence of the tsunami 

was in excessive currents, notably in California at Santa Cruz and Crescent City.

As designed, with model sea level set at MHW, the forecast erred on the side of

conservatism. In the northern portion of the reference model domain (excluded 

in the forecast model C grid), the greatest response was predicted with inundation of the Doran Beach spit and the Dillon Beach / Lawson’s Landing area at the

north and south ends of Bodega Bay. Although in reality no actual inundation

occurred due to the state of the tide, video clips posted online document strong 

currents beneath the Lawson’s Landing pier, and oscillations of 2–3 ft with 20 min

periodicity were reported for Dillon Beach. Examination of the model time series,

both the reference and forecast versions, from Bodega Bay (not shown) indicate

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 23 
that the northern and southern portions were rising and falling together, so the

large amplitudes responsible for the inundation pattern were not associated with

the excitation of an alongshore standing wave mode. Also shown in Figure 18 is 

the CalEMA Inundation Line, based on an ensemble of synthetic mega-tsunami

scenarios. The MHW-based model prediction does impact, albeit at a lesser level,

the regions that the CalEMA study identifies as vulnerable.

4.4 Model validation with other preferred historical events

We now proceed to examine, for several other historical cases highlighted in

Table 1a and Figure 6, how well the reference and forecast model solutions

compare with observation. These are among the preferred cases in the NCTR

protocol to be applied in the validation of Pacific Ocean forecast models. The reference and forecast model time series are intercompared at Point Reyes tide gauge, 

Arena Cove, and San Francisco, and are validated where possible with observation, and the same representations of maximum amplitude, pointwise correlation,

and snapshots of the reference and forecast model fields are drawn.

The results, displayed and described below, represent other DART-detected

and well-documented recent events: 2010 Chile, 2009 Samoa, and 2006 Kuril, the

latter being the first substantial event for which direct observation of the tsunami

wave train was available from multiple deep water DART sites. These events

occurred subsequent to the installation of the tide gauge at Point Reyes. Two preDART cases are included in this section: 1964 Alaska and 1946 Unimak, whose

large amplitudes caused severe damage to Hawaii and provided the impetus for

the establishment of the TWCs. Source characterization for these events is based

on the literature, with the source mechanism estimated from the seismic record.

For the 2010 Chile event, the direct comparison of the reference and forecast

model appears in Figure 19 with satisfactory results, both in terms of reference to forecast model intercomparison and agreement with the observed time

series at the three locations displayed in Figure 20. The amplitude series match 

well throughout the six-hour period shown, and there is strong pointwise correlation throughout the common domain. Comparisons of observations with predictions based on the dedicated forecast models are to be found in the forecast model

reports for Arena Cove (Spillane, in press) and San Francisco (Uslu et al., 2010)

and in post-event reports online at the NCTR website. Excellent agreement is seen

for Point Reyes and San Francisco, although the leading wave at Point Reyes is

overestimated and the timing of some later features at San Francisco is less than

perfect. The observational record at Arena Cove is noisier, although the amplitude

of the first wave is captured well by both models.

For the 2009 Samoa event, the equivalent set of results is shown in Figures 21 

and 22. Despite the considerably more complex structure of the maximum amplitude field, the forecast model pattern is in good agreement with that from the reference model and the time series for the first few hours agree well. Later, the forecast

model solution appears to decay faster than that from the reference model. Considering the Point Reyes observations in Figure 22, the reference model is in better

agreement with the amplitude of later waves. At San Francisco, the situation is

24 Spillane
less clear, with the reference model perhaps overestimating the observed response,

while at Arena Cove, neither model (as extracted from the A grid) reproduces the

severe ringing evident in the observations.

Figures 23 and 24 represent the 2006 Kuril event. Agreement between the

models is strong, both for the early and later portions of the record shown. However,

in comparisons with observations, the models underestimate later features in the

San Francisco observations, and the forecast model response decays far too rapidly

at Arena Cove. At both locations outside the C grid, the predicted maxima are less

than 50% of what was observed. To summarize these three events, with weaker

impacts than the 2011 Honshu event, the accuracy of a revised “coastal forecast”

based on the A and B grids may be reduced. It remains to be demonstrated whether

they are significantly better than those based on Green’s law.

The 1964 Alaska and 1946 Unimak events were widely felt along the U.S. West

Coast, although the greatest impact was to the Hawaiian Islands. The model representations of these major pre-DART events are illustrated in Figures 25–28. The 

reference and forecast model representations of the 1964 Alaska event in the C grid

are seen (Figure 25) to be in close agreement, both in terms of their maxima and

at the arrival of the first wave peak. During the 1964 Alaska event, a runup of

240 cm was reported for Drakes Bay (Point Reyes) with 274 cm at Muir Beach

and 113 cm at San Francisco. Arena Cove and Bodega Bay experienced runups of

183 cm and 76 cm, respectively. The maxima of the model time series (Figure 26) 

are in good agreement with these reports, although both the reference and forecast

model amplitudes for the first wave at San Francisco are about twice the observed

value. 

The representation of the 1946 Unimak event is also satisfactory, with close

agreement of the pattern of reference and forecast model maxima, the time series of 

wave amplitude and velocity at the Point Reyes reference point, and for the instantaneous “snapshots” of these fields an hour after the leading peak (Figure 27). 

Reported runups associated with the 1946 Unimak event were 240 cm at Arena

Cove, 130 cm at Bolinas, and 256 cm at Muir Beach; runup at San Francisco and

Alameda were 26 cm and 20 cm, respectively. The model hindcasts for San Francisco (Figure 28) are in reasonable agreement with the observation, and the model

maximum at Point Reyes is consistent with the reported runup at nearby Bolinas.

The model result for Arena Cove considerably underestimates the reported value.

This may be due to the coarse representation of Arena Cove in the A grid of the

present model, with the better result for the 1964 Alaska event being fortuitious,

or indicative of directionality as a factor in model fidelity. However, for both events,

the results support the usefulness of model results beyond the C grid for forecast

purposes.

4.5 Other historical simulations of interest at Point Reyes, California

The above analysis has documented good agreement between the forecast model

and the slower-running reference version. This permits us to simulate the balance

of the historical cases (and the remaining mega-tsunami scenarios) in Table 1a, 

where impacts to the study area have been reported with the forecast model alone.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 25 
These runs are intended to further validate the stability of the forecast model but

also provide some information on the exposure of the region to tsunamis generated 

at various points on the periphery of the Pacific.

The quality of the modeling of the historical events highlighted above is likely

to be the result of good characterizations of the source, based on DART observations in the case of recent tsunamis or extensive post-event analysis in the case

of the historical examples. In the absence of direct and timely observations, the

successes of the forecast models are likely to be much reduced. An extreme case

in point is the 1896 Sanriku event, a so-called “tsunami-earthquake” (Dudley and

Lee, 1998), causing devastating losses in Japan despite its modest magnitude and

scant warning in the form of ground motion. A digitized marigram from Sausalito

(across the Golden Gate from San Francisco) is available from the NTWC archives

and is drawn in the lower panel of Figure 29. While the timing is reasonably

represented, the amplitude considerably underestimates the reported runup of 10

cm at Sausalito and 20 cm at San Francisco. The nearest location outside the bay

to report runup for this event was Santa Cruz, at 150 cm.

For the 1957 Andreanof event, reported runup values of 29 cm at Bodega Bay,

26 cm at San Francisco, and 18 cm at Alameda are in reasonable agreement with

the model results (35 cm, 46 cm, and 23 cm, respectively). No observed time series

is available for comparison for this event, nor for the 1994 East Kuril event. For

the latter, only a 4 cm runup reported at Alameda is available for validation; the

maximum model amplitude for Alameda at 2.5 cm is in good agreement. For the

remaining events in Table 1a, time series are available for more thorough validation and are displayed in Figures 30–36 with limited comment; runup values from

the NGDC database, where available, are added as annotations to the graphics.

The impact of the 1952 Kamchatka Mw 9.0 event is available as a marigram

from San Francisco (Figure 30). Its amplitude there is well represented by the

model, suggesting that a runup of 3 m or more may have occurred at Point Reyes

and elsewhere in Marin County. For the 1960 Chile Mw 9.5 event, the character

of the observed response is quite different from the model representation. As seen

in Figure 31, the model exceeds the observed amplitude response by a factor of

2–3, and lacks the higher frequency components evident in the observations some

hours into the event. The model wave arrives about 20 min early. At Alameda,

also within San Francisco Bay, the maximum amplitude of the model, at 68 cm, is

about twice the reported runup of 31 cm. At Stinson Beach, the model exaggeration

is less severe: 217 cm compared to the observed 152 cm, but is again large (68 cm

compared to the observed 25 cm) near Bodega Bay.

Figure 32 presents the validation results for the 1996 Andreanof event. At Point

Reyes the agreement is quite good, and at Alameda the weak model waves seem

to capture some of the features of the observed series. At Arena Cove, however,

the signal is far too weak to be visible against the high noise background. For the

2001 Peru (Figure 33) and 2003 Hokkaido (Figure 34) events, the validation is 

quite satisfactory, but for the winter 2003 Rat Island event, as seen in Figure 35, 

there is considerable noise at the validation sites, limiting the visibility of signals

as weak as the model predicts. This event is, however, notable in that, aided by

direct observations of bottom pressure from precursors to the DART array, useful

26 Spillane
forecasts were provided to inform Hawaii’s emergency response. The 2006 Tonga

event proved useful for validation of the Point Reyes model, with a strong response,

shown in Figure 36, that agrees well with observation.

The year 2007 brought several events with which to validate the model, beginning with the normal thrust earthquake seaward of the Kuril Trench in January

2007. As seen in Figure 37, the model correctly captured the leading trough and 

amplitude seen at Point Reyes and San Francisco, although at Arena Cove, the

background noise limits the usefulness of the observations. The 2007 Solomon

event hindcast (Figure 38) is reasonably satisfactory but the signal in both the

model and the observations is weak. In August, an event off Peru (Figure 39) 

appears to match well the observations at Point Reyes, but at Arena Cove and

San Francisco, while the model seems to capture the amplitude and timing of the

early waves, the later portion of the event is less satisfactory. The final event to be

treated, among those listed in Table 1a, is the weak winter 2007 Chile event. Not

surprisingly, since the forecast amplitudes are very small off California, there is 

not a lot to be learned from this event, displayed in Figure 40.

Several additional events, listed in Table 1b, are available for analysis. Of

these, the 1896 Sanriku event has been presented earlier, and the Cape Mendocino

tsunami of 1992 as the sole, albeit weak, representative of a Cascadia event, is

described in the next Section. The remainder, generally weak in terms of their

impact and most occurring in winter where the noise background limits the signalto-noise ratio, are not reported other than to state that all ran without difficulty or

evidence of instability.

4.6 The Mendocino earthquake of 25 April 1992

Of special interest to northern California is the Mendocino earthquake of 25

April 1992. This has the distinction of being the most recent substantial thrust

event on the Cascadia Subduction Zone. While strike-slip events are commonplace

offshore in this region, as shown in the upper right panel of Figure 41, it is thrust 

faults that have the potential to generate significant vertical displacements of the

seafloor that cause large tsunamis. The epicenter of the 1992 event was on land to

the southeast of the plate triple-junction off Cape Mendocino. Uplift on the order of

a meter of a 25 km stretch of the nearshore, between Cape Mendocino and Punta

Gorda to the south, was evident in a die-off of intertidal organisms, reported by

Carver et al. (1994). Presumably extending offshore too, this deformation is not

well represented by either of the southernmost unit sources (ACSZ A/B65) now

available in the propagation database (see Figure 6, where the epicenter is marked

by the seismic “beach ball”). A custom source, available from NCTR but not part

of the propagation database, is used to model the event for comparison with two

digitized marigrams, obtained from the NTWC archives and plotted in the lower

panels of Figure 41. The model performs reasonably in representing the leading

wave, though the model series had to be delayed by 30 min to achieve alignment.

This time offset, greater both in actual time units and as a percentage of travel

time than those typically necessary to adjust transbasin predictions, may be the

result of the coarse representation of the nearshore bathymetry. Another possible

explanation is that this event, described by González et al. (1995), may have generPMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 27 
ated a train of coastal-trapped edge waves. Traveling slower than normal tsunami

waves taking a deep water route, the edge waves may have resulted in a delayed

arrival and an extended duration for the event. This possibility, and the suggestion

that the ACSZ source line should be extended at least one unit further south, make

this an event worth further study. The reference and forecast models for Point

Reyes and other West Coast models (Eureka, Crescent City, etc.) have a major role

in ongoing risk assessment studies for Cascadia.

To summarize the analysis of historical events in the preceding sections, it

would appear that the Point Reyes forecast model is capable of producing accurate

forecasts for this open coast site on the U.S. West Coast. Though the actual waves

may be difficult to observe accurately at the tide gauge during winter storms, the

objective of producing credible forecasts of sizeable tsunami impacts appears to

have been met. Enhanced “coastal forecast” estimates for locations within the

Point Reyes B grid can be useful, while sites in the A grid (as illustrated by Arena

Cove) may have less utility.

4.7 Simulation of the remaining synthetic mega-tsunami events

We conclude this section with a summary of other model runs, included to verify the

stability of the Point Reyes model, that provide useful information on the exposure

of Point Reyes to potentially hazardous future events within the Pacific. As noted

earlier, the sparse instrumental record of actual events needs to be augmented

with credible scenarios to permit risk assessment. While not pretending to be a

full-blown risk assessment for the Point Reyes and southwest Marin County area,

the full set of mega-tsunamis modeled during stability testing can provide some

early estimates.

Results for the set of 19 mega-tsunami events based on the forecast model are

presented in Figure 42. Each source is a composite of 20 unit sources from the A

and B rows with an evenly distributed slip of 25 m, representing a Mw 9.3 event. A

color-coded square, drawn at the geometric center of each synthetic source, is used

to represent the impact at Point Reyes resulting from that source. The measure of 

impact employed in Figure 42 is the maximum amplitude of the predicted time 

series at the reference point. There is no simple relationship apparent between

source orientation, location, or great circle distance to Point Reyes; focusing associated with seafloor features can more than compensate for the decay associated

with geometric spreading. It is notable that the greatest impact at Point Reyes

comes from transbasin sources rather than from those representing Cascadia. The

latter apparently beam most of their energy directly onshore or offshore into the

open ocean; arrows normal to the plate boundary are used in Figure 42 as an 

approximate indicator of main beam direction.

Further results from the suite of mega-tsunami event scenarios are presented

in Table 7. Seven sites within the C and B grids of the forecast model are represented, with the first being the Point Reyes tide gauge, illustrated graphically in

Figure 42. Limatour Beach is a well-visited recreational site within the Point

Reyes National Seashore; Stinson Beach, adjacent to Bolinas, and Muir Beach

are coastal communities between Point Reyes and the southern limit of the forecast model C grid at Point Bonita. Doran Beach and Lawson’s Landing represent

28 Spillane
communities within Bodega Bay, which is only represented in the forecast model B

grid. San Francisco, also in the B grid, is included owing to the wealth of tsunami

records available there. While Point Reyes has the most (10) instances of the

greatest amplitude among the selected sites, for the mega-tsunami events treated

here, Muir Beach, with seven instances and the two overall greatest impacts, is

clearly threatened. These results are consistent with the large runup reported

at Muir Beach in the historical record. Lawson’s Landing, with the remaining

two cases (one representing the southern end of Cascadia, the other the mid-Aleutians), is also clearly at risk. Given the inundation that might have resulted had

the 2011 Honshu waves arrived under adverse tidal conditions (Figure 18) and 

statements by emergency responders in the “Marin Tsunami” video, Bodega Bay

perhaps warrants a dedicated forecast model, although it lacks an instrumented

reference point. Given the linear geometry and orientation of Bodega and Tomales

bays, version 4 of MOST, which is not limited to north-south and east-west grid

lines, should be well suited.

Finally, the set of 19 mega-tsunami scenarios evaluated here is an approximate

match to the set employed in the CalEMA study that established an inundation

line for California. In Figure 43, an ensemble of the inundation predictions by

the Point Reyes forecast model is compared with the CalEMA results. The forecast model C-grid cells inundated by one or more of the mega-tsunami scenarios

are colored red; the CalEMA inundation line is drawn in blue. (The flooded area,

in square kilometers, associated with each scenario is included in Table 7.) The 

underlying topography in Figure 43 uses the reference model grid to better indicate coastal indentations. The forecast model provides a reasonable match in most

of the threatened areas, particularly the Limantour Spit and Beach areas and

Stinson Beach. In some areas, such as Muir Beach, the reduced resolution of the

forecast model limits the penetration of flooding there. No attempt has been made

to adequately represent Tomales Bay in the forecast model. Its shallowness and

the constrictions at its mouth cannot be adequately represented at the spatial resolution necessitated by the run-time constraints for emergency usage.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 29 
Scenario Flooding Impact Sites Amp.

(Great Circle, km) Area Rank PTR1 LIM2 STN3 MUR4 DOR5 LAW6 SFO7 Rank

ACSZ 56–65 (688) 5.18 7 159 152 160 182 201 224 115 13

ACSZ 50–59 (1278) 4.72 11 202 106 217 373 194 193 203 4

CSSZ 1–10 (2994) 1.18 18 99 69 64 72 48 52 37 18

ACSZ 22–31 (3277) 6.34 4 239 221 288 227 251 333 150 6

ACSZ 16–25 (3731) 4.97 8 266 121 234 275 162 194 102 8

ACSZ 6–15 (4731) 2.55 17 134 87 117 136 118 120 81 17

KISZ 1–10 (5856) 4.93 10 354 152 184 245 144 189 90 6

CSSZ 37–46 (6070) 0 19 42 36 38 35 37 38 25 19

KISZ 22–31 (7724) 4.24 12 251 129 170 231 212 182 74 11

NTSZ 30–39 (8054) 7.00 2 402 226 263 277 239 309 127 3

KISZ 32–41 (8368) 6.39 3 318 169 288 502 361 440 159 2

RNSZ 12–21 (8808) 3.27 15 209 84 115 162 110 121 57 14

KISZ 56–65 (9429) 3.94 13 166 96 145 233 171 204 87 12

NVSZ 28–37 (9553) 4.96 9 258 131 149 149 173 202 88 10

MOSZ 1–10 (9943) 7.71 1 460 295 324 513 240 277 200 1

CSSZ 89–98 (10063) 3.48 14 140 134 102 78 102 136 43 16

NGSZ 3–12 (10801) 3.15 16 162 107 143 145 133 131 104 15

EPSZ 6–15 (10932) 6.31 5 246 160 264 296 211 235 137 7

CSSZ 102–111 (11010) 3.27 6 265 132 156 193 157 172 77 9

Overall Max. 402 295 324 513 361 440 203

1–Point Reyes Tide Gauge; 2–Limantour Beach; 3–Stinson Beach; 4–Muir Beach; 

B-Grid: 5–Doran Spit; 6–Lawson’s Landing; 7–San Francisco Tide Gauge

Table 7: Mega-tsunami scenario impacts, represented by flooding and maximum amplitude at several 

sites within the model domain.

30 Spillane
5. Conclusions

To conclude, good agreement between observations and model predictions for a

subset of historical events, including the recent 2011 Honshu tsunami, has been

established, and the stability of the model for numerous synthetic events has been

demonstrated. In particular, the reliability of the forecast model, designed to

run rapidly in real-time emergency conditions, has been proven by the favorable

comparison with reference model predictions, particularly during the early hours

of an event. The model will be included in the SIFT system employed operationally at the Tsunami Warning Centers, and will permit the Point Reyes, California

beaches and the communities of Bolinas, Stinson Beach, and Muir Beach to be

added to the coastal communities for which forecast capability is available. Additionally, this model will provide a tool for use in risk assessment studies.

In addition to the scenarios run by the author and reported here, further tests

have been made by other members of the group at NCTR, and will continue to be

made by staff at the Tsunami Warning Centers and others, perhaps in training

situations. Among the many related tools developed at NCTR is ComMIT (the 

Community Model Interface for Tsunamis; Titov et al., 2011), which provides a

highly intuitive graphical environment in which to exercise and explore forecast

models for any combination of propagation database unit sources. Were any of these

avenues to reveal a problem with the model, its origin (most likely in some quirk of

the bathymetric files) would be located and corrected, with the revised version then

re-installed for operational use. The development of the forecast system will be a

dynamic process, with new models added (and old ones revisited) from the current

list of U.S. interests nationally and globally. As algorithms and methodologies to

represent meteo- or landslide-generated tsunamis become available in the coming

years, the utility of current forecast models beyond purely seismic events could

well expand.

6. Acknowledgments

Many members of the NCTR group provided valuable assistance in the production

of this report. In particular, Diego Arcas edited the first draft for content and style.

An anonymous reviewer provided numerous valuable suggestions. Nazila Merati,

Yong Wei, and Jean Newman performed the SIFT testing reported in Appendix C.

CalEMA and other California entities distribute GIS online datasets used in the

graphics. The modeling could not proceed without the detailed DEM produced at

NGDC by the painstaking combination of numerous bathymetric and topographic

surveys. Digitized marigrams for a number of historic events were acquired from

the NTWC archives. This publication is partially funded by the Joint Institute

for the Study of the Atmosphere and Ocean (JISAO) under NOAA Cooperative 

Agreements NA17RJ1232 and NA10OAR4320148. This is JISAO Contribution

No. 2088, PMEL Contribution No. 3401, and NOAA ISI ID283.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 31 

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(2011): A second generation of tsunami inundation maps for the state of

California. Pure and Appl. Geophys., 168(11), 2133–2146.

Carignan, K.S., L.A. Taylor, B.W. Eakins, R.J. Caldwell, D.Z. Friday, P.R.

Grothe, and E. Lim. (2010): Digital Elevation Models of Central California

and San Francisco Bay: Procedures, Data Sources and Analysis. ngdc.noaa.

gov/dem/report/download/1220.

Carver, G.A., A.S. Jayko, D.W. Valentine, and W.H. Li (1994): Coastal uplift

associated with the 1992 Cape Mendocino earthquake, northern California.

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Census Bureau (2010): United States Census Bureau American FactFinder

Community Facts. URL: factfinder2.census.gov/faces/nav/jsf/pages/

community_facts.xhtml.

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Dunbar, P. (2007): Increasing public awareness of natural hazards via the internet. Nat. Hazards, 42(3) doi:10.1007/s11069-006-9072-3, 529–536.

Gica, E., M. Spillane, V.V. Titov, C.D. Chamberlin, and J.C. Newman (2008):

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González, F.I., K. Satake, E.F. Boss, and H.O. Mofjeld (1995): Edge wave and

non-trapped modes of the 25 April 1992 Cape Mendocino tsunami. Pure 

and Appl. Geophys., 144(3–4), 409–426, doi:10.1007/BF00874375.

Kanamori, H., and J.J. Cipar (1974): Focal process of the great Chilean earthquake, May 22, 1960. Phys. Earth Planet. Inter., 9, 128–136.

Lander, J.F., and P.A. Lockridge (1989): United States tsunamis (including

United States possessions): 1690–1988. US Department of Commerce,

NOAA, NESDIS, and NGDC, Publication 41-2, 265 pp.

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usgs.gov/gip/95/index.html.

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López, A.M., and E.A. Okal (2006): A seismological reassessment of the source

of the 1946 Aleutian “tsunami” earthquake. Geophys. J. Int., 165(3), 835–

849, doi:10.1111/j.1365- 246x.2006.02899.x.

Niemi, T.M., and N.T. Hall (1996): Historical changes in the tidal marsh of

Tomales Bay and Olema Creek, Marin County, California. J. Coastal Res., 

12(1), 90–102.

O’Brien, M.P. (1946): Preliminary Report on Seismic Sea Waves from Aleutian

Earthquake of April 1, 1946, Tech. Rep. HE 116207, Wave Project, Fluid

Mechanics Lab., University of California, Berkeley.

Paros, J., E. Bernard, J. Delaney, C. Meinig, M. Spillane, P. Migliacio, L. Tang,

W. Chadwick, T. Schaad, and S. Stalin (2011): Breakthrough underwater

technology holds promise for improved local tsunami warnings. Oceans ‘11 

MTS/IEEE, Kona, Hawaii, 19–22 September 2011.

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010-9688-1, 567–590.

Spillane, M.C., E. Gica, V.V. Titov, and H.O. Mofjeld (2008): Tsunameter network design for the U.S. DART® arrays in the Pacific and Atlantic oceans.

NOAA Tech. Memo. OAR PMEL-143, 165 pp.

Spillane, M.C.: A Tsunami Forecast Model for Arena Cove, California. US Department of Commerce, NOAA OAR Special Report, PMEL Tsunami Forecast Series, in press. 

Tang, L., C. Chamberlin, E. Tolkova, M. Spillane, V.V. Titov, E.N. Bernard,

and H.O. Mofjeld (2006): Assessment of potential tsunami impact for Pearl

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100617, 36 pp.

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Titov, V.V., and C.E. Synolakis (1998). Numerical modeling of tidal wave

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PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 35 

FIGURES

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 37 

Figure 1: The Point Reyes area of west and south Marin County, California.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 39 
Figure 2: Extract from the oblique 3-D view of the San Francisco DEM provided by NGDC. The focus is Point Reyes;

areas of potential inundation identified by CalEMA are highlighted in red.

Figure 3: View of the Point Reyes headland and Drakes Bay in its lee.

40 Spillane
Figure 4: Distribution of the historical tsunami sources employed for the development of the Point Reyes forecast model. Those highlighted in red are more

extensively investigated using the reference model.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 41 
Figure 5: A sample time interval from the Point Reyes tsunami-capable tide gauge, unrelated to

tsunami activity. The evolving surface wave spectrum is shown in the lower panel.

42 Spillane
Figure 6: The setting of Point Reyes and its nested forecast model grids. The C grids of other West Coast 

forecast models are marked, as are various sites with data available for this study. The closest unit sources

of the propagation database lie north of Cape Mendocino, and the epicenter of the most recent Cascadia

thrust event is marked.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 43 
Figure 7: Nested grid representation for the Point Reyes reference model (RM).

44 Spillane
Figure 8: Nested grid representation for the Point Reyes forecast model (FM).

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 45 
Figure 9: Comparison of the reference (RM) and forecast model (FM) time series at the warning

point for three “micro-tsunami” sources in the Western Pacific. The lowest panel illustrates the

appearance of model instability before the reference model C-grid bathymetry was finalized.

46 Spillane
Figure 10: Locations of synthetic tsunami scenarios employed in model development. Three micro-tsunami scenarios and the magnitude 7.5 case employ a

single unit source; 19 combine 10 pairs of unit sources to model mega-tsunamis. Details are provided in Table 6. Cases highlighted in red have both forecastand reference model solutions.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 47 
Figure 11: Comparison of reference and forecast model results for the ACSZ 56–65 synthetic mega-tsunami,

representing the Cascadia Subduction Zone. (a) Distributions of maximum amplitude in the reference (upper

panel) and forecast (lower panel) model results with their time series (reference model–black, forecast model–

red) and lagged correlation at the Point Reyes tide gauge as insets.

(a)

48 Spillane
Figure 11, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 49 
Figure 11, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

50 Spillane
Figure 11, continued: (d) as in (c) but at the later time when the reference and forecast model solutions have

diverged somewhat.

(d)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 51 
Figure 12: Comparison of reference and forecast model results for the synthetic KISZ 01–10 mega-tsunami,

representing Kamchatka. (a) Distributions of maximum amplitude in the reference (upper panel) and forecast

(lower panel) model results with their time series (reference model–black, forecast model–red) and lagged

correlation at the Point Reyes tide gauge as insets.

(a)

52 Spillane
Figure 12, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 53 
Figure 12, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel)

and forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

54 Spillane
Figure 12, continued: (d) as in (c) but at the later time near the end of the simulation.

(d)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 55 
Figure 13: Comparison of reference and forecast model results for the synthetic NTSZ 30–39 event representing Samoa. (a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower

panel) model results with their time series (reference model–black, forecast model–red) and lagged correlation

at the Point Reyes tide gauge as insets.

(a)

56 Spillane
Figure 13, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 57 
Figure 13, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

58 Spillane
Figure 13, continued: (d) as in (c) but at the later time when the reference and forecast model solutions have

diverged somewhat.

(d)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 59 
Figure 14: Comparison of reference and forecast model results for a moderate synthetic event at NTSZ B36

near Samoa. (a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel)

model results with their time series (reference model–black, forecast model–red) and lagged correlation at the

Point Reyes tide gauge as insets.

(a)

60 Spillane
Figure 14, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 61 
Figure 14, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first major wave peak).

(c)

62 Spillane
Figure 14, continued: (d) as in (c) but at the later time when the reference and forecast model solutions have

diverged somewhat.

(d)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 63 
Figure 15: Observed time series (red curves) from DART® and MARS bottom pressure sensors during the 2011 Honshu event, compared with the

forecast model representation (black curves) based on the propagation database (see Table 1(a)). Model time series in the right-hand panel havebeen lagged, and a common scale factor of 1.2 applied.

64 Spillane
Figure 16: Comparison of observations with reference and forecast model-predicted time series for the historical 2011 Honshu event at selected locations

where tide gauge data are available: (a) Point Reyes, Arena Cove, and San Francisco; (b) Bolinas (6-min data), Alameda, and Richmond. The time periodhighlighted in yellow marks an outage of 18 min or more that occured for the 1-min data streams along the entire West Coast during the event. Runupvalues from the NGDC catalog, when available, are indicated in the lower right of each panel for this and subsequent figures.

(a) (b)

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 65 
Figure 17: Comparison of reference and forecast model results for the historical 2011 Honshu event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model

results with their time series (reference model–black, forecast model–red) and lagged correlation at the Point

Reyes tide gauge as insets.

(a)

66 Spillane
Figure 17, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 67 
Figure 17, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

68 Spillane
Figure 17, continued: (d) as in (c) but during a later wave peak.

(d)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 69 
Figure 17, continued: (e) as in (c) and (d) but during a later wave trough.

(e)

70 Spillane
Figure 18: Inundation forecast from the reference model (RM) C grid for the 2011 Honshu event,

compared with the CalEMA inundation line. The inset in the upper right shows tide gauge data from

Point Reyes. Actual tides were well below MHW so the inundation forecast was overly conservative.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 71 
Figure 19: Comparison of reference and forecast model results for the historical 2010 Chile event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model results

with their time series (reference model–black, forecast model–red) and lagged correlation at the Point Reyes

tide gauge as insets.

(a)

72 Spillane
Figure 19, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 73 
Figure 19, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

74 Spillane
Figure 20: Modeled and observed time series comparison for the

historical 2010 Chile event.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 75 
Figure 21: Comparison of reference and forecast model results for the historical 2009 Samoa event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model

results with their time series (reference model–black, forecast model–red) and lagged correlation at the Point

Reyes tide gauge as insets.

(a)

76 Spillane
Figure 21, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 77 
Figure 21, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at a time between waves at the reference point.

(c)

78 Spillane
Figure 22: Modeled and observed time series comparison for the

historical 2009 Samoa event.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 79 
Figure 23: Comparison of reference and forecast model results for the historical 2006 Kuril event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model

results with their time series (reference model–black, forecast model–red) and lagged correlation at the Point

Reyes tide gauge as insets.

(a)

80 Spillane
Figure 23, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 81 
Figure 23, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

82 Spillane
Figure 24: Modeled and observed time series comparison for the

historical 2006 Kuril event.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 83 
Figure 25: Comparison of reference and forecast model results for the historical 1964 Alaska event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model

results with their time series (reference model–black, forecast model–red) and lagged correlation at the Point

Reyes tide gauge as insets.

(a)

84 Spillane
Figure 25, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 85 
Figure 25, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at the time indicated in the upper panel inset (the first wave peak).

(c)

86 Spillane
Figure 26: Modeled and observed time series comparison for the

historical 1964 Alaska event.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 87 
Figure 27: Comparison of reference and forecast model results for the historical 1946 Unimak event.

(a) Distributions of maximum amplitude in the reference (upper panel) and forecast (lower panel) model results

with their time series (reference model–black, forecast model–red) and lagged correlation at the Point Reyes

tide gauge as insets.

(a)

88 Spillane
Figure 27, continued: (b) distributions of maximum speed in the reference (upper panel) and forecast (lower

panel) model results with the time series of the vector components at the Point Reyes tide gauge as insets.

(b)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 89 
Figure 27, continued: (c) comparison of the wave amplitude and currents in the reference (upper panel) and

forecast (lower panel) model results at a later wave peak.

(c)

90 Spillane
Figure 28: Modeled and observed time series comparison for the

historical 1946 Unimak event.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 91 
Figure 29: Modeled and observed time series comparison for the

Sanriku event of 15 June 1896.

Figure 30: Modeled and observed time series comparison for theKamchatka event of 4 November 1952.

92 Spillane
Figure 31: Modeled and observed time series comparison for the

Chile event of 22 May 1960.

Figure 32: Modeled and observed time series comparison for theAndreanof event of 10 June 1996.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 93 
Figure 33: Modeled and observed time series comparison for the

Peru event of 23 June 2001.

Figure 34: Modeled and observed time series comparison for theHokkaido event of 25 September 2003.

94 Spillane
Figure 35: Modeled and observed time series comparison for the

Rat Island event of 17 November 2003.

Figure 36: Modeled and observed time series comparison for theTonga event of 3 May 2006.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 95 
Figure 37: Modeled and observed time series comparison for the

normal thrust event off the Kuril Islands on 13 January 2007.

Figure 38: Modeled and observed time series comparison for theSolomon event of 1 April 2007.

96 Spillane
Figure 39: Modeled and observed time series comparison for the

Peru event of 15 August 2007.

Figure 40: Modeled and observed time series comparison for theChile event of 14 November 2007.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 97 
Figure 41: The Cape Mendocino event of 25 April 1992. The upper panels show the

frequency of non-thrust events in the vicinity, with only two having a focal mechanism

characteristic of subduction. The lower panels show a comparison of the forecast model

with observations at Arena Cove and Point Reyes.

98 Spillane
Figure 42: Predicted maximum sea level (from the forecast model) at the Point Reyes tide gauge that might result were “mega-tsunamis” to occur at various

locations around the Pacific basin.

PMEL Tsunami ForecastSeries: Vol. 6—PointReyes, California 99 
Figure 43: Chart of the area inundated by one or more of the mega-tsunami scenarios based on the forecast model. Shown in blue is the CalEMA inundation

line, which is based on a similar ensemble of scenarios.

100 Spillane
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 101 

Appendix A. Model input files for Point Reyes, 

California

As discussed in Section 3.5, input files providing model parameters, the file

names of the nested grids, and the output specifications are necessary in order

to run the model in either its reference or forecast mode. These files are provided

below; each record contains the value(s) and an annotation of purpose.

A1. Reference model *.in file for Point Reyes, California

The following table contains the parameter and file choices used in the input file

for the SIFT implementation (most3_facts_nc.in) of the reference model (RM) for

Point Reyes, California. When run on an Intel® Xeon® E5670 2.93 GHz processor

during development the model simulated 4 hr in 2.69 CPU hr.

0.001 Minimum amplitude of input offshore wave (m)

1.5 Minimum depth of offshore (m)

0.1 Dry land depth of inundation (m)

0.0009 Friction coefficient (n**2)

1 Let A Grid and B Grid run up

900.0 Max eta before blow-up (m)

1.0 Time step (sec)

28800 Total number of time steps in run

2 Time steps between A-grid computations

1 Time steps between B-grid computations

30 Time steps between output steps

0 Time steps before saving first output step

1 Save output every n-th grid point, n=

PtReyesCA_RM_A.most A-grid bathymetry file

PtReyesCA_RM_B.most B-grid bathymetry file

PtReyesCA_RM_C.most C-grid bathymetry file

./ Directory of source files

./ Directory for output files

1 1 1 1 netCDF output for A, B, C, SIFT

1 Number of time series locations

3 335 967 Grid & cell indices for reference point
102 Spillane

A2. Forecast model *.in file for Point Reyes, California

The following table contains the parameter and file choices used in the input file

for the SIFT implementation (most3_facts_nc.in) of the optimized forecast model

(FM) for Point Reyes, California. When run on an Intel® Xeon® E5670 2.93 GHz

processor the model simulates 4 hr in under 8 min, satisfying the 10 min target

for this metric.

0.001 Minimum amplitude of input offshore wave (m)

2.5 Minimum depth of offshore (m)

0.1 Dry land depth of inundation (m)

0.0009 Friction coefficient (n**2)

1 Let A Grid and B Grid run up

900.0 Max eta before blow-up (m)

2.0 Time step (sec)

32400 Total number of time steps in run

3 Time steps between A-grid computations

1 Time steps between B-grid computations

15 Time steps between output steps

0 Time steps before saving first output step

1 Save output every n-th grid point, n=

PtReyesCA_FM_A.most A-grid bathymetry file

PtReyesCA_FM_B.most B-grid bathymetry file

PtReyesCA_FM_C.most C-grid bathymetry file

./ Directory of source files

./ Directory for output files

1 1 1 1 netCDF output for A, B, C, SIFT

1 Number of time series locations

3 139 125 Grid & cell indices 

for 237.02333333 37.99666667
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 103 

Appendix B. Propagation Database

Pacific Ocean Unit Sources

The NOAA propagation database presented in this section is the representation

of the database as of March 2013, and may not be the most current version of the

database available upon publication.

PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 105 Figure B1: Aleutian–Alaska–Cascadia Subduction Zone unit sources.

1

5

10

15 20

25

30

40

35

45

50

55

60

65

 a, b

 165°E

 180°W

 165°W 150°W

 135°W

 40°N

 45°N

 50°N

 55°N

 60°N
106 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

acsz-1a Aleutian–Alaska–Cascadia 164.7994 55.9606 299 17 19.61

acsz-1b Aleutian–Alaska–Cascadia 164.4310 55.5849 299 17 5

acsz-2a Aleutian–Alaska–Cascadia 166.3418 55.4016 310.2 17 19.61

acsz-2b Aleutian–Alaska–Cascadia 165.8578 55.0734 310.2 17 5

acsz-3a Aleutian–Alaska–Cascadia 167.2939 54.8919 300.2 23.36 24.82

acsz-3b Aleutian–Alaska–Cascadia 166.9362 54.5356 300.2 23.36 5

acsz-4a Aleutian–Alaska–Cascadia 168.7131 54.2852 310.2 38.51 25.33

acsz-4b Aleutian–Alaska–Cascadia 168.3269 54.0168 310.2 24 5

acsz-5a Aleutian–Alaska–Cascadia 169.7447 53.7808 302.8 37.02 23.54

acsz-5b Aleutian–Alaska–Cascadia 169.4185 53.4793 302.8 21.77 5

acsz-6a Aleutian–Alaska–Cascadia 171.0144 53.3054 303.2 35.31 22.92

acsz-6b Aleutian–Alaska–Cascadia 170.6813 52.9986 303.2 21 5

acsz-7a Aleutian–Alaska–Cascadia 172.1500 52.8528 298.2 35.56 20.16

acsz-7b Aleutian–Alaska–Cascadia 171.8665 52.5307 298.2 17.65 5

acsz-8a Aleutian–Alaska–Cascadia 173.2726 52.4579 290.8 37.92 20.35

acsz-8b Aleutian–Alaska–Cascadia 173.0681 52.1266 290.8 17.88 5

acsz-9a Aleutian–Alaska–Cascadia 174.5866 52.1434 289 39.09 21.05

acsz-9b Aleutian–Alaska–Cascadia 174.4027 51.8138 289 18.73 5

acsz-10a Aleutian–Alaska–Cascadia 175.8784 51.8526 286.1 40.51 20.87

acsz-10b Aleutian–Alaska–Cascadia 175.7265 51.5245 286.1 18.51 5

acsz-11a Aleutian–Alaska–Cascadia 177.1140 51.6488 280 15 17.94

acsz-11b Aleutian–Alaska–Cascadia 176.9937 51.2215 280 15 5

acsz-12a Aleutian–Alaska–Cascadia 178.4500 51.5690 273 15 17.94

acsz-12b Aleutian–Alaska–Cascadia 178.4130 51.1200 273 15 5

acsz-13a Aleutian–Alaska–Cascadia 179.8550 51.5340 271 15 17.94

acsz-13b Aleutian–Alaska–Cascadia 179.8420 51.0850 271 15 5

acsz-14a Aleutian–Alaska–Cascadia 181.2340 51.5780 267 15 17.94

acsz-14b Aleutian–Alaska–Cascadia 181.2720 51.1290 267 15 5

acsz-15a Aleutian–Alaska–Cascadia 182.6380 51.6470 265 15 17.94

acsz-15b Aleutian–Alaska–Cascadia 182.7000 51.2000 265 15 5

acsz-16a Aleutian–Alaska–Cascadia 184.0550 51.7250 264 15 17.94

acsz-16b Aleutian–Alaska–Cascadia 184.1280 51.2780 264 15 5

acsz-17a Aleutian–Alaska–Cascadia 185.4560 51.8170 262 15 17.94

acsz-17b Aleutian–Alaska–Cascadia 185.5560 51.3720 262 15 5

acsz-18a Aleutian–Alaska–Cascadia 186.8680 51.9410 261 15 17.94

acsz-18b Aleutian–Alaska–Cascadia 186.9810 51.4970 261 15 5

acsz-19a Aleutian–Alaska–Cascadia 188.2430 52.1280 257 15 17.94

acsz-19b Aleutian–Alaska–Cascadia 188.4060 51.6900 257 15 5

continued on next page

Table B1: Earthquake parameters for Aleutian–Alaska–Cascadia Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 107 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

acsz-20a Aleutian–Alaska–Cascadia 189.5810 52.3550 251 15 17.94

acsz-20b Aleutian–Alaska–Cascadia 189.8180 51.9300 251 15 5

acsz-21a Aleutian–Alaska–Cascadia 190.9570 52.6470 251 15 17.94

acsz-21b Aleutian–Alaska–Cascadia 191.1960 52.2220 251 15 5

acsz-21z Aleutian–Alaska–Cascadia 190.7399 53.0443 250.8 15 30.88

acsz-22a Aleutian–Alaska–Cascadia 192.2940 52.9430 247 15 17.94

acsz-22b Aleutian–Alaska–Cascadia 192.5820 52.5300 247 15 5

acsz-22z Aleutian–Alaska–Cascadia 192.0074 53.3347 247.8 15 30.88

acsz-23a Aleutian–Alaska–Cascadia 193.6270 53.3070 245 15 17.94

acsz-23b Aleutian–Alaska–Cascadia 193.9410 52.9000 245 15 5

acsz-23z Aleutian–Alaska–Cascadia 193.2991 53.6768 244.6 15 30.88

acsz-24a Aleutian–Alaska–Cascadia 194.9740 53.6870 245 15 17.94

acsz-24b Aleutian–Alaska–Cascadia 195.2910 53.2800 245 15 5

acsz-24y Aleutian–Alaska–Cascadia 194.3645 54.4604 244.4 15 43.82

acsz-24z Aleutian–Alaska–Cascadia 194.6793 54.0674 244.6 15 30.88

acsz-25a Aleutian–Alaska–Cascadia 196.4340 54.0760 250 15 17.94

acsz-25b Aleutian–Alaska–Cascadia 196.6930 53.6543 250 15 5

acsz-25y Aleutian–Alaska–Cascadia 195.9009 54.8572 247.9 15 43.82

acsz-25z Aleutian–Alaska–Cascadia 196.1761 54.4536 248.1 15 30.88

acsz-26a Aleutian–Alaska–Cascadia 197.8970 54.3600 253 15 17.94

acsz-26b Aleutian–Alaska–Cascadia 198.1200 53.9300 253 15 5

acsz-26y Aleutian–Alaska–Cascadia 197.5498 55.1934 253.1 15 43.82

acsz-26z Aleutian–Alaska–Cascadia 197.7620 54.7770 253.3 15 30.88

acsz-27a Aleutian–Alaska–Cascadia 199.4340 54.5960 256 15 17.94

acsz-27b Aleutian–Alaska–Cascadia 199.6200 54.1600 256 15 5

acsz-27x Aleutian–Alaska–Cascadia 198.9736 55.8631 256.5 15 56.24

acsz-27y Aleutian–Alaska–Cascadia 199.1454 55.4401 256.6 15 43.82

acsz-27z Aleutian–Alaska–Cascadia 199.3135 55.0170 256.8 15 30.88

acsz-28a Aleutian–Alaska–Cascadia 200.8820 54.8300 253 15 17.94

acsz-28b Aleutian–Alaska–Cascadia 201.1080 54.4000 253 15 5

acsz-28x Aleutian–Alaska–Cascadia 200.1929 56.0559 252.5 15 56.24

acsz-28y Aleutian–Alaska–Cascadia 200.4167 55.6406 252.7 15 43.82

acsz-28z Aleutian–Alaska–Cascadia 200.6360 55.2249 252.9 15 30.88

acsz-29a Aleutian–Alaska–Cascadia 202.2610 55.1330 247 15 17.94

acsz-29b Aleutian–Alaska–Cascadia 202.5650 54.7200 247 15 5

acsz-29x Aleutian–Alaska–Cascadia 201.2606 56.2861 245.7 15 56.24

acsz-29y Aleutian–Alaska–Cascadia 201.5733 55.8888 246 15 43.82

acsz-29z Aleutian–Alaska–Cascadia 201.8797 55.4908 246.2 15 30.88

continued on next page

Table B1: (continued)
108 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

acsz-30a Aleutian–Alaska–Cascadia 203.6040 55.5090 240 15 17.94

acsz-30b Aleutian–Alaska–Cascadia 203.9970 55.1200 240 15 5

acsz-30w Aleutian–Alaska–Cascadia 201.9901 56.9855 239.5 15 69.12

acsz-30x Aleutian–Alaska–Cascadia 202.3851 56.6094 239.8 15 56.24

acsz-30y Aleutian–Alaska–Cascadia 202.7724 56.2320 240.2 15 43.82

acsz-30z Aleutian–Alaska–Cascadia 203.1521 55.8534 240.5 15 30.88

acsz-31a Aleutian–Alaska–Cascadia 204.8950 55.9700 236 15 17.94

acsz-31b Aleutian–Alaska–Cascadia 205.3400 55.5980 236 15 5

acsz-31w Aleutian–Alaska–Cascadia 203.0825 57.3740 234.5 15 69.12

acsz-31x Aleutian–Alaska–Cascadia 203.5408 57.0182 234.9 15 56.24

acsz-31y Aleutian–Alaska–Cascadia 203.9904 56.6607 235.3 15 43.82

acsz-31z Aleutian–Alaska–Cascadia 204.4315 56.3016 235.7 15 30.88

acsz-32a Aleutian–Alaska–Cascadia 206.2080 56.4730 236 15 17.94

acsz-32b Aleutian–Alaska–Cascadia 206.6580 56.1000 236 15 5

acsz-32w Aleutian–Alaska–Cascadia 204.4129 57.8908 234.3 15 69.12

acsz-32x Aleutian–Alaska–Cascadia 204.8802 57.5358 234.7 15 56.24

acsz-32y Aleutian–Alaska–Cascadia 205.3385 57.1792 235.1 15 43.82

acsz-32z Aleutian–Alaska–Cascadia 205.7880 56.8210 235.5 15 30.88

acsz-33a Aleutian–Alaska–Cascadia 207.5370 56.9750 236 15 17.94

acsz-33b Aleutian–Alaska–Cascadia 207.9930 56.6030 236 15 5

acsz-33w Aleutian–Alaska–Cascadia 205.7126 58.3917 234.2 15 69.12

acsz-33x Aleutian–Alaska–Cascadia 206.1873 58.0371 234.6 15 56.24

acsz-33y Aleutian–Alaska–Cascadia 206.6527 57.6808 235 15 43.82

acsz-33z Aleutian–Alaska–Cascadia 207.1091 57.3227 235.4 15 30.88

acsz-34a Aleutian–Alaska–Cascadia 208.9371 57.5124 236 15 17.94

acsz-34b Aleutian–Alaska–Cascadia 209.4000 57.1400 236 15 5

acsz-34w Aleutian–Alaska–Cascadia 206.9772 58.8804 233.5 15 69.12

acsz-34x Aleutian–Alaska–Cascadia 207.4677 58.5291 233.9 15 56.24

acsz-34y Aleutian–Alaska–Cascadia 207.9485 58.1760 234.3 15 43.82

acsz-34z Aleutian–Alaska–Cascadia 208.4198 57.8213 234.7 15 30.88

acsz-35a Aleutian–Alaska–Cascadia 210.2597 58.0441 230 15 17.94

acsz-35b Aleutian–Alaska–Cascadia 210.8000 57.7000 230 15 5

acsz-35w Aleutian–Alaska–Cascadia 208.0204 59.3199 228.8 15 69.12

acsz-35x Aleutian–Alaska–Cascadia 208.5715 58.9906 229.3 15 56.24

acsz-35y Aleutian–Alaska–Cascadia 209.1122 58.6590 229.7 15 43.82

acsz-35z Aleutian–Alaska–Cascadia 209.6425 58.3252 230.2 15 30.88

acsz-36a Aleutian–Alaska–Cascadia 211.3249 58.6565 218 15 17.94

acsz-36b Aleutian–Alaska–Cascadia 212.0000 58.3800 218 15 5

continued on next page

Table B1: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 109 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

acsz-36w Aleutian–Alaska–Cascadia 208.5003 59.5894 215.6 15 69.12

acsz-36x Aleutian–Alaska–Cascadia 209.1909 59.3342 216.2 15 56.24

acsz-36y Aleutian–Alaska–Cascadia 209.8711 59.0753 216.8 15 43.82

acsz-36z Aleutian–Alaska–Cascadia 210.5412 58.8129 217.3 15 30.88

acsz-37a Aleutian–Alaska–Cascadia 212.2505 59.2720 213.7 15 17.94

acsz-37b Aleutian–Alaska–Cascadia 212.9519 59.0312 213.7 15 5

acsz-37x Aleutian–Alaska–Cascadia 210.1726 60.0644 213 15 56.24

acsz-37y Aleutian–Alaska–Cascadia 210.8955 59.8251 213.7 15 43.82

acsz-37z Aleutian–Alaska–Cascadia 211.6079 59.5820 214.3 15 30.88

acsz-38a Aleutian–Alaska–Cascadia 214.6555 60.1351 260.1 0 15

acsz-38b Aleutian–Alaska–Cascadia 214.8088 59.6927 260.1 0 15

acsz-38y Aleutian–Alaska–Cascadia 214.3737 60.9838 259 0 15

acsz-38z Aleutian–Alaska–Cascadia 214.5362 60.5429 259 0 15

acsz-39a Aleutian–Alaska–Cascadia 216.5607 60.2480 267 0 15

acsz-39b Aleutian–Alaska–Cascadia 216.6068 59.7994 267 0 15

acsz-40a Aleutian–Alaska–Cascadia 219.3069 59.7574 310.9 0 15

acsz-40b Aleutian–Alaska–Cascadia 218.7288 59.4180 310.9 0 15

acsz-41a Aleutian–Alaska–Cascadia 220.4832 59.3390 300.7 0 15

acsz-41b Aleutian–Alaska–Cascadia 220.0382 58.9529 300.7 0 15

acsz-42a Aleutian–Alaska–Cascadia 221.8835 58.9310 298.9 0 15

acsz-42b Aleutian–Alaska–Cascadia 221.4671 58.5379 298.9 0 15

acsz-43a Aleutian–Alaska–Cascadia 222.9711 58.6934 282.3 0 15

acsz-43b Aleutian–Alaska–Cascadia 222.7887 58.2546 282.3 0 15

acsz-44a Aleutian–Alaska–Cascadia 224.9379 57.9054 340.9 12 11.09

acsz-44b Aleutian–Alaska–Cascadia 224.1596 57.7617 340.9 7 5

acsz-45a Aleutian–Alaska–Cascadia 225.4994 57.1634 334.1 12 11.09

acsz-45b Aleutian–Alaska–Cascadia 224.7740 56.9718 334.1 7 5

acsz-46a Aleutian–Alaska–Cascadia 226.1459 56.3552 334.1 12 11.09

acsz-46b Aleutian–Alaska–Cascadia 225.4358 56.1636 334.1 7 5

acsz-47a Aleutian–Alaska–Cascadia 226.7731 55.5830 332.3 12 11.09

acsz-47b Aleutian–Alaska–Cascadia 226.0887 55.3785 332.3 7 5

acsz-48a Aleutian–Alaska–Cascadia 227.4799 54.6763 339.4 12 11.09

acsz-48b Aleutian–Alaska–Cascadia 226.7713 54.5217 339.4 7 5

acsz-49a Aleutian–Alaska–Cascadia 227.9482 53.8155 341.2 12 11.09

acsz-49b Aleutian–Alaska–Cascadia 227.2462 53.6737 341.2 7 5

acsz-50a Aleutian–Alaska–Cascadia 228.3970 53.2509 324.5 12 11.09

acsz-50b Aleutian–Alaska–Cascadia 227.8027 52.9958 324.5 7 5

acsz-51a Aleutian–Alaska–Cascadia 229.1844 52.6297 318.4 12 11.09

continued on next page

Table B1: (continued)
110 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

acsz-51b Aleutian–Alaska–Cascadia 228.6470 52.3378 318.4 7 5

acsz-52a Aleutian–Alaska–Cascadia 230.0306 52.0768 310.9 12 11.09

acsz-52b Aleutian–Alaska–Cascadia 229.5665 51.7445 310.9 7 5

acsz-53a Aleutian–Alaska–Cascadia 231.1735 51.5258 310.9 12 11.09

acsz-53b Aleutian–Alaska–Cascadia 230.7150 51.1935 310.9 7 5

acsz-54a Aleutian–Alaska–Cascadia 232.2453 50.8809 314.1 12 11.09

acsz-54b Aleutian–Alaska–Cascadia 231.7639 50.5655 314.1 7 5

acsz-55a Aleutian–Alaska–Cascadia 233.3066 49.9032 333.7 12 11.09

acsz-55b Aleutian–Alaska–Cascadia 232.6975 49.7086 333.7 7 5

acsz-56a Aleutian–Alaska–Cascadia 234.0588 49.1702 315 11 12.82

acsz-56b Aleutian–Alaska–Cascadia 233.5849 48.8584 315 9 5

acsz-57a Aleutian–Alaska–Cascadia 234.9041 48.2596 341 11 12.82

acsz-57b Aleutian–Alaska–Cascadia 234.2797 48.1161 341 9 5

acsz-58a Aleutian–Alaska–Cascadia 235.3021 47.3812 344 11 12.82

acsz-58b Aleutian–Alaska–Cascadia 234.6776 47.2597 344 9 5

acsz-59a Aleutian–Alaska–Cascadia 235.6432 46.5082 345 11 12.82

acsz-59b Aleutian–Alaska–Cascadia 235.0257 46.3941 345 9 5

acsz-60a Aleutian–Alaska–Cascadia 235.8640 45.5429 356 11 12.82

acsz-60b Aleutian–Alaska–Cascadia 235.2363 45.5121 356 9 5

acsz-61a Aleutian–Alaska–Cascadia 235.9106 44.6227 359 11 12.82

acsz-61b Aleutian–Alaska–Cascadia 235.2913 44.6150 359 9 5

acsz-62a Aleutian–Alaska–Cascadia 235.9229 43.7245 359 11 12.82

acsz-62b Aleutian–Alaska–Cascadia 235.3130 43.7168 359 9 5

acsz-63a Aleutian–Alaska–Cascadia 236.0220 42.9020 350 11 12.82

acsz-63b Aleutian–Alaska–Cascadia 235.4300 42.8254 350 9 5

acsz-64a Aleutian–Alaska–Cascadia 235.9638 41.9818 345 11 12.82

acsz-64b Aleutian–Alaska–Cascadia 235.3919 41.8677 345 9 5

acsz-65a Aleutian–Alaska–Cascadia 236.2643 41.1141 345 11 12.82

acsz-65b Aleutian–Alaska–Cascadia 235.7000 41.0000 345 9 5

acsz-238a Aleutian–Alaska–Cascadia 213.2878 59.8406 236.8 15 17.94

acsz-238y Aleutian–Alaska–Cascadia 212.3424 60.5664 236.8 15 43.82

acsz-238z Aleutian–Alaska–Cascadia 212.8119 60.2035 236.8 15 30.88

Table B1: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 111 

Figure B2: Central and South America Subduction Zone unit sources.

1

5 10 15

20 25

30 35

40

45

50

55

60

65

70

75

80

85

90

95

100

105

110

115

 108°W 99°W 90°W 81°W 72°W 63°W

 54°S

 36°S

 18°S

 0° 

 18°N

b,a
112 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-1a Central and South America 254.4573 20.8170 359 19 15.4

cssz-1b Central and South America 254.0035 20.8094 359 12 5

cssz-1z Central and South America 254.7664 20.8222 359 50 31.67

cssz-2a Central and South America 254.5765 20.2806 336.8 19 15.4

cssz-2b Central and South America 254.1607 20.1130 336.8 12 5

cssz-3a Central and South America 254.8789 19.8923 310.6 18.31 15.27

cssz-3b Central and South America 254.5841 19.5685 310.6 11.85 5

cssz-4a Central and South America 255.6167 19.2649 313.4 17.62 15.12

cssz-4b Central and South America 255.3056 18.9537 313.4 11.68 5

cssz-5a Central and South America 256.2240 18.8148 302.7 16.92 15

cssz-5b Central and South America 255.9790 18.4532 302.7 11.54 5

cssz-6a Central and South America 256.9425 18.4383 295.1 16.23 14.87

cssz-6b Central and South America 256.7495 18.0479 295.1 11.38 5

cssz-7a Central and South America 257.8137 18.0339 296.9 15.54 14.74

cssz-7b Central and South America 257.6079 17.6480 296.9 11.23 5

cssz-8a Central and South America 258.5779 17.7151 290.4 14.85 14.61

cssz-8b Central and South America 258.4191 17.3082 290.4 11.08 5

cssz-9a Central and South America 259.4578 17.4024 290.5 14.15 14.47

cssz-9b Central and South America 259.2983 16.9944 290.5 10.92 5

cssz-10a Central and South America 260.3385 17.0861 290.8 13.46 14.34

cssz-10b Central and South America 260.1768 16.6776 290.8 10.77 5

cssz-11a Central and South America 261.2255 16.7554 291.8 12.77 14.21

cssz-11b Central and South America 261.0556 16.3487 291.8 10.62 5

cssz-12a Central and South America 262.0561 16.4603 288.9 12.08 14.08

cssz-12b Central and South America 261.9082 16.0447 288.9 10.46 5

cssz-13a Central and South America 262.8638 16.2381 283.2 11.38 13.95

cssz-13b Central and South America 262.7593 15.8094 283.2 10.31 5

cssz-14a Central and South America 263.6066 16.1435 272.1 10.69 13.81

cssz-14b Central and South America 263.5901 15.7024 272.1 10.15 5

cssz-15a Central and South America 264.8259 15.8829 293 10 13.68

cssz-15b Central and South America 264.6462 15.4758 293 10 5

cssz-15y Central and South America 265.1865 16.6971 293 10 31.05

cssz-15z Central and South America 265.0060 16.2900 293 10 22.36

cssz-16a Central and South America 265.7928 15.3507 304.9 15 15.82

cssz-16b Central and South America 265.5353 14.9951 304.9 12.5 5

cssz-16y Central and South America 266.3092 16.0619 304.9 15 41.7

cssz-16z Central and South America 266.0508 15.7063 304.9 15 28.76

cssz-17a Central and South America 266.4947 14.9019 299.5 20 17.94

cssz-17b Central and South America 266.2797 14.5346 299.5 15 5

cssz-17y Central and South America 266.9259 15.6365 299.5 20 52.14

continued on next page

Table B2: Earthquake parameters for Central and South America Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 113 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-17z Central and South America 266.7101 15.2692 299.5 20 35.04

cssz-18a Central and South America 267.2827 14.4768 298 21.5 17.94

cssz-18b Central and South America 267.0802 14.1078 298 15 5

cssz-18y Central and South America 267.6888 15.2148 298 21.5 54.59

cssz-18z Central and South America 267.4856 14.8458 298 21.5 36.27

cssz-19a Central and South America 268.0919 14.0560 297.6 23 17.94

cssz-19b Central and South America 267.8943 13.6897 297.6 15 5

cssz-19y Central and South America 268.4880 14.7886 297.6 23 57.01

cssz-19z Central and South America 268.2898 14.4223 297.6 23 37.48

cssz-20a Central and South America 268.8929 13.6558 296.2 24 17.94

cssz-20b Central and South America 268.7064 13.2877 296.2 15 5

cssz-20y Central and South America 269.1796 14.2206 296.2 45.5 73.94

cssz-20z Central and South America 269.0362 13.9382 296.2 45.5 38.28

cssz-21a Central and South America 269.6797 13.3031 292.6 25 17.94

cssz-21b Central and South America 269.5187 12.9274 292.6 15 5

cssz-21x Central and South America 269.8797 13.7690 292.6 68 131.8

cssz-21y Central and South America 269.8130 13.6137 292.6 68 85.43

cssz-21z Central and South America 269.7463 13.4584 292.6 68 39.07

cssz-22a Central and South America 270.4823 13.0079 288.6 25 17.94

cssz-22b Central and South America 270.3492 12.6221 288.6 15 5

cssz-22x Central and South America 270.6476 13.4864 288.6 68 131.8

cssz-22y Central and South America 270.5925 13.3269 288.6 68 85.43

cssz-22z Central and South America 270.5374 13.1674 288.6 68 39.07

cssz-23a Central and South America 271.3961 12.6734 292.4 25 17.94

cssz-23b Central and South America 271.2369 12.2972 292.4 15 5

cssz-23x Central and South America 271.5938 13.1399 292.4 68 131.8

cssz-23y Central and South America 271.5279 12.9844 292.4 68 85.43

cssz-23z Central and South America 271.4620 12.8289 292.4 68 39.07

cssz-24a Central and South America 272.3203 12.2251 300.2 25 17.94

cssz-24b Central and South America 272.1107 11.8734 300.2 15 5

cssz-24x Central and South America 272.5917 12.6799 300.2 67 131.1

cssz-24y Central and South America 272.5012 12.5283 300.2 67 85.1

cssz-24z Central and South America 272.4107 12.3767 300.2 67 39.07

cssz-25a Central and South America 273.2075 11.5684 313.8 25 17.94

cssz-25b Central and South America 272.9200 11.2746 313.8 15 5

cssz-25x Central and South America 273.5950 11.9641 313.8 66 130.4

cssz-25y Central and South America 273.4658 11.8322 313.8 66 84.75

cssz-25z Central and South America 273.3366 11.7003 313.8 66 39.07

cssz-26a Central and South America 273.8943 10.8402 320.4 25 17.94

continued on next page

Table B2: (continued)
114 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-26b Central and South America 273.5750 10.5808 320.4 15 5

cssz-26x Central and South America 274.3246 11.1894 320.4 66 130.4

cssz-26y Central and South America 274.1811 11.0730 320.4 66 84.75

cssz-26z Central and South America 274.0377 10.9566 320.4 66 39.07

cssz-27a Central and South America 274.4569 10.2177 316.1 25 17.94

cssz-27b Central and South America 274.1590 9.9354 316.1 15 5

cssz-27z Central and South America 274.5907 10.3444 316.1 66 39.07

cssz-28a Central and South America 274.9586 9.8695 297.1 22 14.54

cssz-28b Central and South America 274.7661 9.4988 297.1 11 5

cssz-28z Central and South America 275.1118 10.1643 297.1 42.5 33.27

cssz-29a Central and South America 275.7686 9.4789 296.6 19 11.09

cssz-29b Central and South America 275.5759 9.0992 296.6 7 5

cssz-30a Central and South America 276.6346 8.9973 302.2 19 9.36

cssz-30b Central and South America 276.4053 8.6381 302.2 5 5

cssz-31a Central and South America 277.4554 8.4152 309.1 19 7.62

cssz-31b Central and South America 277.1851 8.0854 309.1 3 5

cssz-31z Central and South America 277.7260 8.7450 309.1 19 23.9

cssz-32a Central and South America 278.1112 7.9425 303 18.67 8.49

cssz-32b Central and South America 277.8775 7.5855 303 4 5

cssz-32z Central and South America 278.3407 8.2927 303 21.67 24.49

cssz-33a Central and South America 278.7082 7.6620 287.6 18.33 10.23

cssz-33b Central and South America 278.5785 7.2555 287.6 6 5

cssz-33z Central and South America 278.8328 8.0522 287.6 24.33 25.95

cssz-34a Central and South America 279.3184 7.5592 269.5 18 17.94

cssz-34b Central and South America 279.3223 7.1320 269.5 15 5

cssz-35a Central and South America 280.0039 7.6543 255.9 17.67 14.54

cssz-35b Central and South America 280.1090 7.2392 255.9 11 5

cssz-35x Central and South America 279.7156 8.7898 255.9 29.67 79.22

cssz-35y Central and South America 279.8118 8.4113 255.9 29.67 54.47

cssz-35z Central and South America 279.9079 8.0328 255.9 29.67 29.72

cssz-36a Central and South America 281.2882 7.6778 282.5 17.33 11.09

cssz-36b Central and South America 281.1948 7.2592 282.5 7 5

cssz-36x Central and South America 281.5368 8.7896 282.5 32.33 79.47

cssz-36y Central and South America 281.4539 8.4190 282.5 32.33 52.73

cssz-36z Central and South America 281.3710 8.0484 282.5 32.33 25.99

cssz-37a Central and South America 282.5252 6.8289 326.9 17 10.23

cssz-37b Central and South America 282.1629 6.5944 326.9 6 5

cssz-38a Central and South America 282.9469 5.5973 355.4 17 10.23

cssz-38b Central and South America 282.5167 5.5626 355.4 6 5

continued on next page

Table B2: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 115 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-39a Central and South America 282.7236 4.3108 24.13 17 10.23

cssz-39b Central and South America 282.3305 4.4864 24.13 6 5

cssz-39z Central and South America 283.0603 4.1604 24.13 35 24.85

cssz-40a Central and South America 282.1940 3.3863 35.28 17 10.23

cssz-40b Central and South America 281.8427 3.6344 35.28 6 5

cssz-40y Central and South America 282.7956 2.9613 35.28 35 53.52

cssz-40z Central and South America 282.4948 3.1738 35.28 35 24.85

cssz-41a Central and South America 281.6890 2.6611 34.27 17 10.23

cssz-41b Central and South America 281.3336 2.9030 34.27 6 5

cssz-41z Central and South America 281.9933 2.4539 34.27 35 24.85

cssz-42a Central and South America 281.2266 1.9444 31.29 17 10.23

cssz-42b Central and South America 280.8593 2.1675 31.29 6 5

cssz-42z Central and South America 281.5411 1.7533 31.29 35 24.85

cssz-43a Central and South America 280.7297 1.1593 33.3 17 10.23

cssz-43b Central and South America 280.3706 1.3951 33.3 6 5

cssz-43z Central and South America 281.0373 0.9573 33.3 35 24.85

cssz-44a Central and South America 280.3018 0.4491 28.8 17 10.23

cssz-44b Central and South America 279.9254 0.6560 28.8 6 5

cssz-45a Central and South America 279.9083 -0.3259 26.91 10 8.49

cssz-45b Central and South America 279.5139 -0.1257 26.91 4 5

cssz-46a Central and South America 279.6461 -0.9975 15.76 10 8.49

cssz-46b Central and South America 279.2203 -0.8774 15.76 4 5

cssz-47a Central and South America 279.4972 -1.7407 6.9 10 8.49

cssz-47b Central and South America 279.0579 -1.6876 6.9 4 5

cssz-48a Central and South America 279.3695 -2.6622 8.96 10 8.49

cssz-48b Central and South America 278.9321 -2.5933 8.96 4 5

cssz-48y Central and South America 280.2444 -2.8000 8.96 10 25.85

cssz-48z Central and South America 279.8070 -2.7311 8.96 10 17.17

cssz-49a Central and South America 279.1852 -3.6070 13.15 10 8.49

cssz-49b Central and South America 278.7536 -3.5064 13.15 4 5

cssz-49y Central and South America 280.0486 -3.8082 13.15 10 25.85

cssz-49z Central and South America 279.6169 -3.7076 13.15 10 17.17

cssz-50a Central and South America 279.0652 -4.3635 4.78 10.33 9.64

cssz-50b Central and South America 278.6235 -4.3267 4.78 5.33 5

cssz-51a Central and South America 279.0349 -5.1773 359.4 10.67 10.81

cssz-51b Central and South America 278.5915 -5.1817 359.4 6.67 5

cssz-52a Central and South America 279.1047 -5.9196 349.8 11 11.96

cssz-52b Central and South America 278.6685 -5.9981 349.8 8 5

cssz-53a Central and South America 279.3044 -6.6242 339.2 10.25 11.74

continued on next page

Table B2: (continued)
116 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-53b Central and South America 278.8884 -6.7811 339.2 7.75 5

cssz-53y Central and South America 280.1024 -6.3232 339.2 19.25 37.12

cssz-53z Central and South America 279.7035 -6.4737 339.2 19.25 20.64

cssz-54a Central and South America 279.6256 -7.4907 340.8 9.5 11.53

cssz-54b Central and South America 279.2036 -7.6365 340.8 7.5 5

cssz-54y Central and South America 280.4267 -7.2137 340.8 20.5 37.29

cssz-54z Central and South America 280.0262 -7.3522 340.8 20.5 19.78

cssz-55a Central and South America 279.9348 -8.2452 335.4 8.75 11.74

cssz-55b Central and South America 279.5269 -8.4301 335.4 7.75 5

cssz-55x Central and South America 281.0837 -7.7238 335.4 21.75 56.4

cssz-55y Central and South America 280.7009 -7.8976 335.4 21.75 37.88

cssz-55z Central and South America 280.3180 -8.0714 335.4 21.75 19.35

cssz-56a Central and South America 280.3172 -8.9958 331.6 8 11.09

cssz-56b Central and South America 279.9209 -9.2072 331.6 7 5

cssz-56x Central and South America 281.4212 -8.4063 331.6 23 57.13

cssz-56y Central and South America 281.0534 -8.6028 331.6 23 37.59

cssz-56z Central and South America 280.6854 -8.7993 331.6 23 18.05

cssz-57a Central and South America 280.7492 -9.7356 328.7 8.6 10.75

cssz-57b Central and South America 280.3640 -9.9663 328.7 6.6 5

cssz-57x Central and South America 281.8205 -9.0933 328.7 23.4 57.94

cssz-57y Central and South America 281.4636 -9.3074 328.7 23.4 38.08

cssz-57z Central and South America 281.1065 -9.5215 328.7 23.4 18.22

cssz-58a Central and South America 281.2275 -10.5350 330.5 9.2 10.4

cssz-58b Central and South America 280.8348 -10.7532 330.5 6.2 5

cssz-58y Central and South America 281.9548 -10.1306 330.5 23.8 38.57

cssz-58z Central and South America 281.5913 -10.3328 330.5 23.8 18.39

cssz-59a Central and South America 281.6735 -11.2430 326.2 9.8 10.05

cssz-59b Central and South America 281.2982 -11.4890 326.2 5.8 5

cssz-59y Central and South America 282.3675 -10.7876 326.2 24.2 39.06

cssz-59z Central and South America 282.0206 -11.0153 326.2 24.2 18.56

cssz-60a Central and South America 282.1864 -11.9946 326.5 10.4 9.71

cssz-60b Central and South America 281.8096 -12.2384 326.5 5.4 5

cssz-60y Central and South America 282.8821 -11.5438 326.5 24.6 39.55

cssz-60z Central and South America 282.5344 -11.7692 326.5 24.6 18.73

cssz-61a Central and South America 282.6944 -12.7263 325.5 11 9.36

cssz-61b Central and South America 282.3218 -12.9762 325.5 5 5

cssz-61y Central and South America 283.3814 -12.2649 325.5 25 40.03

cssz-61z Central and South America 283.0381 -12.4956 325.5 25 18.9

cssz-62a Central and South America 283.1980 -13.3556 319 11 9.79

continued on next page

Table B2: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 117 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-62b Central and South America 282.8560 -13.6451 319 5.5 5

cssz-62y Central and South America 283.8178 -12.8300 319 27 42.03

cssz-62z Central and South America 283.5081 -13.0928 319 27 19.33

cssz-63a Central and South America 283.8032 -14.0147 317.9 11 10.23

cssz-63b Central and South America 283.4661 -14.3106 317.9 6 5

cssz-63z Central and South America 284.1032 -13.7511 317.9 29 19.77

cssz-64a Central and South America 284.4144 -14.6482 315.7 13 11.96

cssz-64b Central and South America 284.0905 -14.9540 315.7 8 5

cssz-65a Central and South America 285.0493 -15.2554 313.2 15 13.68

cssz-65b Central and South America 284.7411 -15.5715 313.2 10 5

cssz-66a Central and South America 285.6954 -15.7816 307.7 14.5 13.68

cssz-66b Central and South America 285.4190 -16.1258 307.7 10 5

cssz-67a Central and South America 286.4127 -16.2781 304.3 14 13.68

cssz-67b Central and South America 286.1566 -16.6381 304.3 10 5

cssz-67z Central and South America 286.6552 -15.9365 304.3 23 25.78

cssz-68a Central and South America 287.2481 -16.9016 311.8 14 13.68

cssz-68b Central and South America 286.9442 -17.2264 311.8 10 5

cssz-68z Central and South America 287.5291 -16.6007 311.8 26 25.78

cssz-69a Central and South America 287.9724 -17.5502 314.9 14 13.68

cssz-69b Central and South America 287.6496 -17.8590 314.9 10 5

cssz-69y Central and South America 288.5530 -16.9934 314.9 29 50.02

cssz-69z Central and South America 288.2629 -17.2718 314.9 29 25.78

cssz-70a Central and South America 288.6731 -18.2747 320.4 14 13.25

cssz-70b Central and South America 288.3193 -18.5527 320.4 9.5 5

cssz-70y Central and South America 289.3032 -17.7785 320.4 30 50.35

cssz-70z Central and South America 288.9884 -18.0266 320.4 30 25.35

cssz-71a Central and South America 289.3089 -19.1854 333.2 14 12.82

cssz-71b Central and South America 288.8968 -19.3820 333.2 9 5

cssz-71y Central and South America 290.0357 -18.8382 333.2 31 50.67

cssz-71z Central and South America 289.6725 -19.0118 333.2 31 24.92

cssz-72a Central and South America 289.6857 -20.3117 352.4 14 12.54

cssz-72b Central and South America 289.2250 -20.3694 352.4 8.67 5

cssz-72z Central and South America 290.0882 -20.2613 352.4 32 24.63

cssz-73a Central and South America 289.7731 -21.3061 358.9 14 12.24

cssz-73b Central and South America 289.3053 -21.3142 358.9 8.33 5

cssz-73z Central and South America 290.1768 -21.2991 358.9 33 24.34

cssz-74a Central and South America 289.7610 -22.2671 3.06 14 11.96

cssz-74b Central and South America 289.2909 -22.2438 3.06 8 5

continued on next page

Table B2: (continued)
118 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-75a Central and South America 289.6982 -23.1903 4.83 14.09 11.96

cssz-75b Central and South America 289.2261 -23.1536 4.83 8 5

cssz-76a Central and South America 289.6237 -24.0831 4.67 14.18 11.96

cssz-76b Central and South America 289.1484 -24.0476 4.67 8 5

cssz-77a Central and South America 289.5538 -24.9729 4.3 14.27 11.96

cssz-77b Central and South America 289.0750 -24.9403 4.3 8 5

cssz-78a Central and South America 289.4904 -25.8621 3.86 14.36 11.96

cssz-78b Central and South America 289.0081 -25.8328 3.86 8 5

cssz-79a Central and South America 289.3491 -26.8644 11.34 14.45 11.96

cssz-79b Central and South America 288.8712 -26.7789 11.34 8 5

cssz-80a Central and South America 289.1231 -27.7826 14.16 14.54 11.96

cssz-80b Central and South America 288.6469 -27.6762 14.16 8 5

cssz-81a Central and South America 288.8943 -28.6409 13.19 14.63 11.96

cssz-81b Central and South America 288.4124 -28.5417 13.19 8 5

cssz-82a Central and South America 288.7113 -29.4680 9.68 14.72 11.96

cssz-82b Central and South America 288.2196 -29.3950 9.68 8 5

cssz-83a Central and South America 288.5944 -30.2923 5.36 14.81 11.96

cssz-83b Central and South America 288.0938 -30.2517 5.36 8 5

cssz-84a Central and South America 288.5223 -31.1639 3.8 14.9 11.96

cssz-84b Central and South America 288.0163 -31.1351 3.8 8 5

cssz-85a Central and South America 288.4748 -32.0416 2.55 15 11.96

cssz-85b Central and South America 287.9635 -32.0223 2.55 8 5

cssz-86a Central and South America 288.3901 -33.0041 7.01 15 11.96

cssz-86b Central and South America 287.8768 -32.9512 7.01 8 5

cssz-87a Central and South America 288.1050 -34.0583 19.4 15 11.96

cssz-87b Central and South America 287.6115 -33.9142 19.4 8 5

cssz-88a Central and South America 287.5309 -35.0437 32.81 15 11.96

cssz-88b Central and South America 287.0862 -34.8086 32.81 8 5

cssz-88z Central and South America 287.9308 -35.2545 32.81 30 24.9

cssz-89a Central and South America 287.2380 -35.5993 14.52 16.67 11.96

cssz-89b Central and South America 286.7261 -35.4914 14.52 8 5

cssz-89z Central and South America 287.7014 -35.6968 14.52 30 26.3

cssz-90a Central and South America 286.8442 -36.5645 22.64 18.33 11.96

cssz-90b Central and South America 286.3548 -36.4004 22.64 8 5

cssz-90z Central and South America 287.2916 -36.7142 22.64 30 27.68

cssz-91a Central and South America 286.5925 -37.2488 10.9 20 11.96

cssz-91b Central and South America 286.0721 -37.1690 10.9 8 5

cssz-91z Central and South America 287.0726 -37.3224 10.9 30 29.06

continued on next page

Table B2: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 119 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-92a Central and South America 286.4254 -38.0945 8.23 20 11.96

cssz-92b Central and South America 285.8948 -38.0341 8.23 8 5

cssz-92z Central and South America 286.9303 -38.1520 8.23 26.67 29.06

cssz-93a Central and South America 286.2047 -39.0535 13.46 20 11.96

cssz-93b Central and South America 285.6765 -38.9553 13.46 8 5

cssz-93z Central and South America 286.7216 -39.1495 13.46 23.33 29.06

cssz-94a Central and South America 286.0772 -39.7883 3.4 20 11.96

cssz-94b Central and South America 285.5290 -39.7633 3.4 8 5

cssz-94z Central and South America 286.6255 -39.8133 3.4 20 29.06

cssz-95a Central and South America 285.9426 -40.7760 9.84 20 11.96

cssz-95b Central and South America 285.3937 -40.7039 9.84 8 5

cssz-95z Central and South America 286.4921 -40.8481 9.84 20 29.06

cssz-96a Central and South America 285.7839 -41.6303 7.6 20 11.96

cssz-96b Central and South America 285.2245 -41.5745 7.6 8 5

cssz-96x Central and South America 287.4652 -41.7977 7.6 20 63.26

cssz-96y Central and South America 286.9043 -41.7419 7.6 20 46.16

cssz-96z Central and South America 286.3439 -41.6861 7.6 20 29.06

cssz-97a Central and South America 285.6695 -42.4882 5.3 20 11.96

cssz-97b Central and South America 285.0998 -42.4492 5.3 8 5

cssz-97x Central and South America 287.3809 -42.6052 5.3 20 63.26

cssz-97y Central and South America 286.8101 -42.5662 5.3 20 46.16

cssz-97z Central and South America 286.2396 -42.5272 5.3 20 29.06

cssz-98a Central and South America 285.5035 -43.4553 10.53 20 11.96

cssz-98b Central and South America 284.9322 -43.3782 10.53 8 5

cssz-98x Central and South America 287.2218 -43.6866 10.53 20 63.26

cssz-98y Central and South America 286.6483 -43.6095 10.53 20 46.16

cssz-98z Central and South America 286.0755 -43.5324 10.53 20 29.06

cssz-99a Central and South America 285.3700 -44.2595 4.86 20 11.96

cssz-99b Central and South America 284.7830 -44.2237 4.86 8 5

cssz-99x Central and South America 287.1332 -44.3669 4.86 20 63.26

cssz-99y Central and South America 286.5451 -44.3311 4.86 20 46.16

cssz-99z Central and South America 285.9574 -44.2953 4.86 20 29.06

cssz-100a Central and South America 285.2713 -45.1664 5.68 20 11.96

cssz-100b Central and South America 284.6758 -45.1246 5.68 8 5

cssz-100x Central and South America 287.0603 -45.2918 5.68 20 63.26

cssz-100y Central and South America 286.4635 -45.2500 5.68 20 46.16

cssz-100z Central and South America 285.8672 -45.2082 5.68 20 29.06

cssz-101a Central and South America 285.3080 -45.8607 352.6 20 9.36

continued on next page

Table B2: (continued)
120 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-101b Central and South America 284.7067 -45.9152 352.6 5 5

cssz-101y Central and South America 286.5089 -45.7517 352.6 20 43.56

cssz-101z Central and South America 285.9088 -45.8062 352.6 20 26.46

cssz-102a Central and South America 285.2028 -47.1185 17.72 5 9.36

cssz-102b Central and South America 284.5772 -46.9823 17.72 5 5

cssz-102y Central and South America 286.4588 -47.3909 17.72 5 18.07

cssz-102z Central and South America 285.8300 -47.2547 17.72 5 13.72

cssz-103a Central and South America 284.7075 -48.0396 23.37 7.5 11.53

cssz-103b Central and South America 284.0972 -47.8630 23.37 7.5 5

cssz-103x Central and South America 286.5511 -48.5694 23.37 7.5 31.11

cssz-103y Central and South America 285.9344 -48.3928 23.37 7.5 24.58

cssz-103z Central and South America 285.3199 -48.2162 23.37 7.5 18.05

cssz-104a Central and South America 284.3440 -48.7597 14.87 10 13.68

cssz-104b Central and South America 283.6962 -48.6462 14.87 10 5

cssz-104x Central and South America 286.2962 -49.1002 14.87 10 39.73

cssz-104y Central and South America 285.6440 -48.9867 14.87 10 31.05

cssz-104z Central and South America 284.9933 -48.8732 14.87 10 22.36

cssz-105a Central and South America 284.2312 -49.4198 0.25 9.67 13.4

cssz-105b Central and South America 283.5518 -49.4179 0.25 9.67 5

cssz-105x Central and South America 286.2718 -49.4255 0.25 9.67 38.59

cssz-105y Central and South America 285.5908 -49.4236 0.25 9.67 30.2

cssz-105z Central and South America 284.9114 -49.4217 0.25 9.67 21.8

cssz-106a Central and South America 284.3730 -50.1117 347.5 9.25 13.04

cssz-106b Central and South America 283.6974 -50.2077 347.5 9.25 5

cssz-106x Central and South America 286.3916 -49.8238 347.5 9.25 37.15

cssz-106y Central and South America 285.7201 -49.9198 347.5 9.25 29.11

cssz-106z Central and South America 285.0472 -50.0157 347.5 9.25 21.07

cssz-107a Central and South America 284.7130 -50.9714 346.5 9 12.82

cssz-107b Central and South America 284.0273 -51.0751 346.5 9 5

cssz-107x Central and South America 286.7611 -50.6603 346.5 9 36.29

cssz-107y Central and South America 286.0799 -50.7640 346.5 9 28.47

cssz-107z Central and South America 285.3972 -50.8677 346.5 9 20.64

cssz-108a Central and South America 285.0378 -51.9370 352 8.67 12.54

cssz-108b Central and South America 284.3241 -51.9987 352 8.67 5

cssz-108x Central and South America 287.1729 -51.7519 352 8.67 35.15

cssz-108y Central and South America 286.4622 -51.8136 352 8.67 27.61

cssz-108z Central and South America 285.7505 -51.8753 352 8.67 20.07

cssz-109a Central and South America 285.2635 -52.8439 353.1 8.33 12.24

cssz-109b Central and South America 284.5326 -52.8974 353.1 8.33 5

continued on next page

Table B2: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 121 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

cssz-109x Central and South America 287.4508 -52.6834 353.1 8.33 33.97

cssz-109y Central and South America 286.7226 -52.7369 353.1 8.33 26.73

cssz-109z Central and South America 285.9935 -52.7904 353.1 8.33 19.49

cssz-110a Central and South America 285.5705 -53.4139 334.2 8 11.96

cssz-110b Central and South America 284.8972 -53.6076 334.2 8 5

cssz-110x Central and South America 287.5724 -52.8328 334.2 8 32.83

cssz-110y Central and South America 286.9081 -53.0265 334.2 8 25.88

cssz-110z Central and South America 286.2408 -53.2202 334.2 8 18.92

cssz-111a Central and South America 286.1627 -53.8749 313.8 8 11.96

cssz-111b Central and South America 285.6382 -54.1958 313.8 8 5

cssz-111x Central and South America 287.7124 -52.9122 313.8 8 32.83

cssz-111y Central and South America 287.1997 -53.2331 313.8 8 25.88

cssz-111z Central and South America 286.6832 -53.5540 313.8 8 18.92

cssz-112a Central and South America 287.3287 -54.5394 316.4 8 11.96

cssz-112b Central and South America 286.7715 -54.8462 316.4 8 5

cssz-112x Central and South America 288.9756 -53.6190 316.4 8 32.83

cssz-112y Central and South America 288.4307 -53.9258 316.4 8 25.88

cssz-112z Central and South America 287.8817 -54.2326 316.4 8 18.92

cssz-113a Central and South America 288.3409 -55.0480 307.6 8 11.96

cssz-113b Central and South America 287.8647 -55.4002 307.6 8 5

cssz-113x Central and South America 289.7450 -53.9914 307.6 8 32.83

cssz-113y Central and South America 289.2810 -54.3436 307.6 8 25.88

cssz-113z Central and South America 288.8130 -54.6958 307.6 8 18.92

cssz-114a Central and South America 289.5342 -55.5026 301.5 8 11.96

cssz-114b Central and South America 289.1221 -55.8819 301.5 8 5

cssz-114x Central and South America 290.7472 -54.3647 301.5 8 32.83

cssz-114y Central and South America 290.3467 -54.7440 301.5 8 25.88

cssz-114z Central and South America 289.9424 -55.1233 301.5 8 18.92

cssz-115a Central and South America 290.7682 -55.8485 292.7 8 11.96

cssz-115b Central and South America 290.4608 -56.2588 292.7 8 5

cssz-115x Central and South America 291.6714 -54.6176 292.7 8 32.83

cssz-115y Central and South America 291.3734 -55.0279 292.7 8 25.88

cssz-115z Central and South America 291.0724 -55.4382 292.7 8 18.92

Table B2: (continued)

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 123 

Figure B3: Eastern Philippines Subduction Zone unit sources.

 120°E 123°E 126°E 129°E 132°E

 0° 

 4°N

 8°N

 12°N

 16°N

 20°N

1

3

5

7

9

11

13

15

17

19

21

a,b
124 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

epsz-0a Eastern Philippines 128.5264 1.5930 180 44 26.92

epsz-0b Eastern Philippines 128.8496 1.5930 180 26 5

epsz-1a Eastern Philippines 128.5521 2.3289 153.6 44.2 27.62

epsz-1b Eastern Philippines 128.8408 2.4720 153.6 26.9 5

epsz-2a Eastern Philippines 128.1943 3.1508 151.9 45.9 32.44

epsz-2b Eastern Philippines 128.4706 3.2979 151.9 32.8 5.35

epsz-3a Eastern Philippines 127.8899 4.0428 155.2 57.3 40.22

epsz-3b Eastern Philippines 128.1108 4.1445 155.2 42.7 6.31

epsz-4a Eastern Philippines 127.6120 4.8371 146.8 71.4 48.25

epsz-4b Eastern Philippines 127.7324 4.9155 146.8 54.8 7.39

epsz-5a Eastern Philippines 127.3173 5.7040 162.9 79.9 57.4

epsz-5b Eastern Philippines 127.3930 5.7272 162.9 79.4 8.25

epsz-6a Eastern Philippines 126.6488 6.6027 178.9 48.6 45.09

epsz-6b Eastern Philippines 126.9478 6.6085 178.9 48.6 7.58

epsz-7a Eastern Philippines 126.6578 7.4711 175.8 50.7 45.52

epsz-7b Eastern Philippines 126.9439 7.4921 175.8 50.7 6.83

epsz-8a Eastern Philippines 126.6227 8.2456 163.3 56.7 45.6

epsz-8b Eastern Philippines 126.8614 8.3164 163.3 48.9 7.92

epsz-9a Eastern Philippines 126.2751 9.0961 164.1 47 43.59

epsz-9b Eastern Philippines 126.5735 9.1801 164.1 44.9 8.3

epsz-10a Eastern Philippines 125.9798 9.9559 164.5 43.1 42.25

epsz-10b Eastern Philippines 126.3007 10.0438 164.5 43.1 8.09

epsz-11a Eastern Philippines 125.6079 10.6557 155 37.8 38.29

epsz-11b Eastern Philippines 125.9353 10.8059 155 37.8 7.64

epsz-12a Eastern Philippines 125.4697 11.7452 172.1 36 37.01

epsz-12b Eastern Philippines 125.8374 11.7949 172.1 36 7.62

epsz-13a Eastern Philippines 125.2238 12.1670 141.5 32.4 33.87

epsz-13b Eastern Philippines 125.5278 12.4029 141.5 32.4 7.08

epsz-14a Eastern Philippines 124.6476 13.1365 158.2 23 25.92

epsz-14b Eastern Philippines 125.0421 13.2898 158.2 23 6.38

epsz-15a Eastern Philippines 124.3107 13.9453 156.1 24.1 26.51

epsz-15b Eastern Philippines 124.6973 14.1113 156.1 24.1 6.09

epsz-16a Eastern Philippines 123.8998 14.4025 140.3 19.5 21.69

epsz-16b Eastern Philippines 124.2366 14.6728 140.3 19.5 5

epsz-17a Eastern Philippines 123.4604 14.7222 117.6 15.3 18.19

epsz-17b Eastern Philippines 123.6682 15.1062 117.6 15.3 5

epsz-18a Eastern Philippines 123.3946 14.7462 67.4 15 17.94

epsz-18b Eastern Philippines 123.2219 15.1467 67.4 15 5

epsz-19a Eastern Philippines 121.3638 15.7400 189.6 15 17.94

epsz-19b Eastern Philippines 121.8082 15.6674 189.6 15 5

epsz-20a Eastern Philippines 121.6833 16.7930 203.3 15 17.94

epsz-20b Eastern Philippines 122.0994 16.6216 203.3 15 5

epsz-21a Eastern Philippines 121.8279 17.3742 184.2 15 17.94

epsz-21b Eastern Philippines 122.2814 17.3425 184.2 15 5

Table B3: Earthquake parameters for Eastern Philippines Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 125 

Figure B4: Kamchatka–Bering Subduction Zone unit sources.

 144°E

 152°E 160°E 168°E

 176°E

 40°N

 44°N

 48°N

 52°N

 56°N

 60°N

1

3

5

z,a,b
126 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kbsz-1a Kamchatka-Bering 161.8374 57.5485 201.5 29 26.13

kbsz-1b Kamchatka-Bering 162.5162 57.4030 202.1 25 5

kbsz-2a Kamchatka-Bering 162.4410 58.3816 201.7 29 26.13

kbsz-2b Kamchatka-Bering 163.1344 58.2343 202.3 25 5

kbsz-2z Kamchatka-Bering 161.7418 58.5249 201.1 29 50.37

kbsz-3a Kamchatka-Bering 163.5174 59.3493 218.9 29 26.13

kbsz-3b Kamchatka-Bering 164.1109 59.1001 219.4 25 5

kbsz-3z Kamchatka-Bering 162.9150 59.5958 218.4 29 50.37

kbsz-4a Kamchatka-Bering 164.7070 60.0632 222.2 29 26.13

kbsz-4b Kamchatka-Bering 165.2833 59.7968 222.7 25 5

kbsz-4z Kamchatka-Bering 164.1212 60.3270 221.7 29 50.37

kbsz-5a Kamchatka-Bering 165.8652 60.7261 220.5 29 26.13

kbsz-5b Kamchatka-Bering 166.4692 60.4683 221 25 5

Table B4: Earthquake parameters for Kamchatka–Bering Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 127 

Figure B5: Kamchatka–Kuril–Japan–Izu–Mariana–Yap Subduction Zone unit sources.

 130°E 140°E 150°E 160°E 170°E

 10°N

 20°N

 30°N

 40°N

 50°N

1

5

25

30

35

40

45

50

55

70

75

10

15

20

60 65

y,z,a,b,c
128 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-0a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 162.8200 56.3667 194.4 29 26.13

kisz-0b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 163.5057 56.2677 195 25 5

kisz-0z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 162.1309 56.4618 193.8 29 50.37

kisz-1a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 162.4318 55.5017 195 29 26.13

kisz-1b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 163.1000 55.4000 195 25 5

kisz-1y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.0884 55.7050 195 29 74.61

kisz-1z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.7610 55.6033 195 29 50.37

kisz-2a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.9883 54.6784 200 29 26.13

kisz-2b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 162.6247 54.5440 200 25 5

kisz-2y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.7072 54.9471 200 29 74.61

kisz-2z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.3488 54.8127 200 29 50.37

kisz-3a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.4385 53.8714 204 29 26.13

kisz-3b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 162.0449 53.7116 204 25 5

kisz-3y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.2164 54.1910 204 29 74.61

kisz-3z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.8286 54.0312 204 29 50.37

kisz-4a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.7926 53.1087 210 29 26.13

kisz-4b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 161.3568 52.9123 210 25 5

kisz-4y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 159.6539 53.5015 210 29 74.61

kisz-4z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.2246 53.3051 210 29 50.37

kisz-5a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.0211 52.4113 218 29 26.13

kisz-5b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 160.5258 52.1694 218 25 5

kisz-5y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 159.0005 52.8950 218 29 74.61

kisz-5z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 159.5122 52.6531 218 29 50.37

kisz-6a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 159.1272 51.7034 218 29 26.13

kisz-6b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 159.6241 51.4615 218 25 5

kisz-6y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 158.1228 52.1871 218 29 74.61

kisz-6z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 158.6263 51.9452 218 29 50.37

kisz-7a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 158.2625 50.9549 214 29 26.13

kisz-7b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 158.7771 50.7352 214 25 5

kisz-7y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 157.2236 51.3942 214 29 74.61

kisz-7z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 157.7443 51.1745 214 29 50.37

kisz-8a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 157.4712 50.2459 218 31 27.7

kisz-8b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 157.9433 50.0089 218 27 5

kisz-8y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.5176 50.7199 218 31 79.2

kisz-8z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.9956 50.4829 218 31 53.45

kisz-9a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.6114 49.5583 220 31 27.7

kisz-9b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 157.0638 49.3109 220 27 5

kisz-9y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 155.6974 50.0533 220 31 79.2

kisz-9z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.1556 49.8058 220 31 53.45

continued on next page

Table B5: Earthquake parameters for Kamchatka-Kuril-Japan-Izu-Mariana-Yap Subduction Zone

unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 129 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-10a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 155.7294 48.8804 221 31 27.7

kisz-10b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.1690 48.6278 221 27 5

kisz-10y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 154.8413 49.3856 221 31 79.2

kisz-10z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 155.2865 49.1330 221 31 53.45

kisz-11a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 154.8489 48.1821 219 31 27.7

kisz-11b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 155.2955 47.9398 219 27 5

kisz-11y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.9472 48.6667 219 31 79.2

kisz-11z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 154.3991 48.4244 219 31 53.45

kisz-11c Kamchatka-Kuril-Japan-Izu-Mariana-Yap 156.0358 47.5374 39 57.89 4.602

kisz-12a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.9994 47.4729 217 31 27.7

kisz-12b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 154.4701 47.2320 217 27 5

kisz-12y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.0856 47.9363 217 31 79.2

kisz-12z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.5435 47.7046 217 31 53.45

kisz-12c Kamchatka-Kuril-Japan-Izu-Mariana-Yap 155.2208 46.8473 37 57.89 4.602

kisz-13a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.2239 46.7564 218 31 27.7

kisz-13b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.6648 46.5194 218 27 5

kisz-13y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 152.3343 47.2304 218 31 79.2

kisz-13z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 152.7801 46.9934 218 31 53.45

kisz-13c Kamchatka-Kuril-Japan-Izu-Mariana-Yap 154.3957 46.1257 38 57.89 4.602

kisz-14a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 152.3657 46.1514 225 23 24.54

kisz-14b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 152.7855 45.8591 225 23 5

kisz-14y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 151.5172 46.7362 225 23 63.62

kisz-14z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 151.9426 46.4438 225 23 44.08

kisz-14c Kamchatka-Kuril-Japan-Izu-Mariana-Yap 153.4468 45.3976 45 57.89 4.602

kisz-15a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 151.4663 45.5963 233 25 23.73

kisz-15b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 151.8144 45.2712 233 22 5

kisz-15y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 150.7619 46.2465 233 25 65.99

kisz-15z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 151.1151 45.9214 233 25 44.86

kisz-16a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 150.4572 45.0977 237 25 23.73

kisz-16b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 150.7694 44.7563 237 22 5

kisz-16y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 149.8253 45.7804 237 25 65.99

kisz-16z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 150.1422 45.4390 237 25 44.86

kisz-17a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 149.3989 44.6084 237 25 23.73

kisz-17b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 149.7085 44.2670 237 22 5

kisz-17y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 148.7723 45.2912 237 25 65.99

kisz-17z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 149.0865 44.9498 237 25 44.86

kisz-18a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 148.3454 44.0982 235 25 23.73

kisz-18b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 148.6687 43.7647 235 22 5

kisz-18y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.6915 44.7651 235 25 65.99

continued on next page

Table B5: (continued)
130 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-18z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 148.0194 44.4316 235 25 44.86

kisz-19a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.3262 43.5619 233 25 23.73

kisz-19b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.6625 43.2368 233 22 5

kisz-19y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.6463 44.2121 233 25 65.99

kisz-19z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.9872 43.8870 233 25 44.86

kisz-20a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.3513 43.0633 237 25 23.73

kisz-20b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.6531 42.7219 237 22 5

kisz-20y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.7410 43.7461 237 25 65.99

kisz-20z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.0470 43.4047 237 25 44.86

kisz-21a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.3331 42.5948 239 25 23.73

kisz-21b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.6163 42.2459 239 22 5

kisz-21y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.7603 43.2927 239 25 65.99

kisz-21z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.0475 42.9438 239 25 44.86

kisz-22a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.3041 42.1631 242 25 23.73

kisz-22b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.5605 41.8037 242 22 5

kisz-22y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.7854 42.8819 242 25 65.99

kisz-22z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.0455 42.5225 242 25 44.86

kisz-23a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.2863 41.3335 202 21 21.28

kisz-23b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.8028 41.1764 202 19 5

kisz-23v Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.6816 42.1189 202 21 110.9

kisz-23w Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.2050 41.9618 202 21 92.95

kisz-23x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.7273 41.8047 202 21 75.04

kisz-23y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.2482 41.6476 202 21 57.12

kisz-23z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7679 41.4905 202 21 39.2

kisz-24a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.9795 40.3490 185 21 21.28

kisz-24b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.5273 40.3125 185 19 5

kisz-24x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.3339 40.4587 185 21 75.04

kisz-24y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.8827 40.4221 185 21 57.12

kisz-24z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.4312 40.3856 185 21 39.2

kisz-25a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.8839 39.4541 185 21 21.28

kisz-25b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.4246 39.4176 185 19 5

kisz-25y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.8012 39.5272 185 21 57.12

kisz-25z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.3426 39.4907 185 21 39.2

kisz-26a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7622 38.5837 188 21 21.28

kisz-26b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.2930 38.5254 188 19 5

kisz-26x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.1667 38.7588 188 21 75.04

kisz-26y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.6990 38.7004 188 21 57.12

kisz-26z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.2308 38.6421 188 21 39.2

kisz-27a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.5320 37.7830 198 21 21.28

continued on next page

Table B5: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 131 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-27b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.0357 37.6534 198 19 5

kisz-27x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.0142 38.1717 198 21 75.04

kisz-27y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.5210 38.0421 198 21 57.12

kisz-27z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.0269 37.9126 198 21 39.2

kisz-28a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.1315 37.0265 208 21 21.28

kisz-28b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.5941 36.8297 208 19 5

kisz-28x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.7348 37.6171 208 21 75.04

kisz-28y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.2016 37.4202 208 21 57.12

kisz-28z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.6671 37.2234 208 21 39.2

kisz-29a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.5970 36.2640 211 21 21.28

kisz-29b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.0416 36.0481 211 19 5

kisz-29y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.7029 36.6960 211 21 57.12

kisz-29z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.1506 36.4800 211 21 39.2

kisz-30a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.0553 35.4332 205 21 21.28

kisz-30b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.5207 35.2560 205 19 5

kisz-30y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.1204 35.7876 205 21 57.12

kisz-30z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.5883 35.6104 205 21 39.2

kisz-31a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.6956 34.4789 190 22 22.1

kisz-31b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.1927 34.4066 190 20 5

kisz-31v Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.2025 34.8405 190 22 115.8

kisz-31w Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.7021 34.7682 190 22 97.02

kisz-31x Kamchatka-Kuril-Japan-Izu-Mariana-Yap 139.2012 34.6958 190 22 78.29

kisz-31y Kamchatka-Kuril-Japan-Izu-Mariana-Yap 139.6997 34.6235 190 22 59.56

kisz-31z Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.1979 34.5512 190 22 40.83

kisz-32a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.0551 33.0921 180 32 23.48

kisz-32b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.5098 33.0921 180 21.69 5

kisz-33a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.0924 32.1047 173.8 27.65 20.67

kisz-33b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.5596 32.1473 173.8 18.27 5

kisz-34a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.1869 31.1851 172.1 25 18.26

kisz-34b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.6585 31.2408 172.1 15.38 5

kisz-35a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.4154 30.1707 163 25 17.12

kisz-35b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.8662 30.2899 163 14.03 5

kisz-36a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.6261 29.2740 161.7 25.73 18.71

kisz-36b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.0670 29.4012 161.7 15.91 5

kisz-37a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.0120 28.3322 154.7 20 14.54

kisz-37b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.4463 28.5124 154.7 11 5

kisz-38a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.2254 27.6946 170.3 20 14.54

kisz-38b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.6955 27.7659 170.3 11 5

kisz-39a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.3085 26.9127 177.2 24.23 17.42

continued on next page

Table B5: (continued)
132 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-39b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7674 26.9325 177.2 14.38 5

kisz-40a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.2673 26.1923 189.4 26.49 22.26

kisz-40b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7090 26.1264 189.4 20.2 5

kisz-41a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.1595 25.0729 173.7 22.07 19.08

kisz-41b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.6165 25.1184 173.7 16.36 5

kisz-42a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7641 23.8947 143.5 21.54 18.4

kisz-42b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.1321 24.1432 143.5 15.54 5

kisz-43a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.5281 23.0423 129.2 23.02 18.77

kisz-43b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.8128 23.3626 129.2 15.99 5

kisz-44a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.2230 22.5240 134.6 28.24 18.56

kisz-44b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.5246 22.8056 134.6 15.74 5

kisz-45a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.0895 21.8866 125.8 36.73 22.79

kisz-45b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.3171 22.1785 125.8 20.84 5

kisz-46a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.6972 21.3783 135.9 30.75 20.63

kisz-46b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.9954 21.6469 135.9 18.22 5

kisz-47a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.0406 20.9341 160.1 29.87 19.62

kisz-47b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.4330 21.0669 160.1 17 5

kisz-48a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.3836 20.0690 158 32.75 19.68

kisz-48b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.7567 20.2108 158 17.07 5

kisz-49a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.6689 19.3123 164.5 25.07 21.41

kisz-49b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.0846 19.4212 164.5 19.16 5

kisz-50a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.9297 18.5663 172.1 22 22.1

kisz-50b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.3650 18.6238 172.1 20 5

kisz-51a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.9495 17.7148 175.1 22.06 22.04

kisz-51b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.3850 17.7503 175.1 19.93 5

kisz-52a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.9447 16.8869 180 25.51 18.61

kisz-52b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.3683 16.8869 180 15.79 5

kisz-53a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.8626 16.0669 185.2 27.39 18.41

kisz-53b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.2758 16.0309 185.2 15.56 5

kisz-54a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.7068 15.3883 199.1 28.12 20.91

kisz-54b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 147.0949 15.2590 199.1 18.56 5

kisz-55a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.4717 14.6025 204.3 29.6 26.27

kisz-55b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.8391 14.4415 204.3 25.18 5

kisz-56a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.1678 13.9485 217.4 32.04 26.79

kisz-56b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 146.4789 13.7170 217.4 25.84 5

kisz-57a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.6515 13.5576 235.8 37 24.54

kisz-57b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.8586 13.2609 235.8 23 5

kisz-58a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.9648 12.9990 237.8 37.72 24.54

kisz-58b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 145.1589 12.6984 237.8 23 5

continued on next page

Table B5: (continued)
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 133 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

kisz-59a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.1799 12.6914 242.9 34.33 22.31

kisz-59b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 144.3531 12.3613 242.9 20.25 5

kisz-60a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.3687 12.3280 244.9 30.9 20.62

kisz-60b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 143.5355 11.9788 244.9 18.2 5

kisz-61a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7051 12.1507 261.8 35.41 25.51

kisz-61b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 142.7582 11.7883 261.8 24.22 5

kisz-62a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.6301 11.8447 245.7 39.86 34.35

kisz-62b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 141.7750 11.5305 245.7 35.94 5

kisz-63a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.8923 11.5740 256.2 42 38.46

kisz-63b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.9735 11.2498 256.2 42 5

kisz-64a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.1387 11.6028 269.6 42.48 38.77

kisz-64b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 140.1410 11.2716 269.6 42.48 5

kisz-65a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 139.4595 11.5883 288.7 44.16 39.83

kisz-65b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 139.3541 11.2831 288.7 44.16 5

kisz-66a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.1823 11.2648 193.1 45 40.36

kisz-66b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.4977 11.1929 193.1 45 5

kisz-67a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.9923 10.3398 189.8 45 40.36

kisz-67b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.3104 10.2856 189.8 45 5

kisz-68a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.7607 9.6136 201.7 45 40.36

kisz-68b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 138.0599 9.4963 201.7 45 5

kisz-69a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.4537 8.8996 213.5 45 40.36

kisz-69b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.7215 8.7241 213.5 45 5

kisz-70a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.0191 8.2872 226.5 45 40.36

kisz-70b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 137.2400 8.0569 226.5 45 5

kisz-71a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 136.3863 7.9078 263.9 45 40.36

kisz-71b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 136.4202 7.5920 263.9 45 5

kisz-72a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 135.6310 7.9130 276.9 45 40.36

kisz-72b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 135.5926 7.5977 276.9 45 5

kisz-73a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 134.3296 7.4541 224 45 40.36

kisz-73b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 134.5600 7.2335 224 45 5

kisz-74a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 133.7125 6.8621 228.1 45 40.36

kisz-74b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 133.9263 6.6258 228.1 45 5

kisz-75a Kamchatka-Kuril-Japan-Izu-Mariana-Yap 133.0224 6.1221 217.7 45 40.36

kisz-75b Kamchatka-Kuril-Japan-Izu-Mariana-Yap 133.2751 5.9280 217.7 45 5

Table B5: (continued)

PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 135 Figure B6: Manus–Oceanic Convergent Boundary Subduction Zone unit sources. 135°E 140°E 145°E 150°E 155°E

 0°

 3°S

 6°S

 9°S 3°N 1 3 5 7 9 11 13 15 17 , a,b
136 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

mosz-1a Manus-Oceanic Convergent Boundary 154.0737 -4.8960 140.2 15 15.88

mosz-1b Manus-Oceanic Convergent Boundary 154.4082 -4.6185 140.2 15 2.94

mosz-2a Manus-Oceanic Convergent Boundary 153.5589 -4.1575 140.2 15 15.91

mosz-2b Manus-Oceanic Convergent Boundary 153.8931 -3.8800 140.2 15 2.97

mosz-3a Manus-Oceanic Convergent Boundary 153.0151 -3.3716 143.9 15 16.64

mosz-3b Manus-Oceanic Convergent Boundary 153.3662 -3.1160 143.9 15 3.7

mosz-4a Manus-Oceanic Convergent Boundary 152.4667 -3.0241 127.7 15 17.32

mosz-4b Manus-Oceanic Convergent Boundary 152.7321 -2.6806 127.7 15 4.38

mosz-5a Manus-Oceanic Convergent Boundary 151.8447 -2.7066 114.3 15 17.57

mosz-5b Manus-Oceanic Convergent Boundary 152.0235 -2.3112 114.3 15 4.63

mosz-6a Manus-Oceanic Convergent Boundary 151.0679 -2.2550 115 15 17.66

mosz-6b Manus-Oceanic Convergent Boundary 151.2513 -1.8618 115 15 4.72

mosz-7a Manus-Oceanic Convergent Boundary 150.3210 -2.0236 107.2 15 17.73

mosz-7b Manus-Oceanic Convergent Boundary 150.4493 -1.6092 107.2 15 4.79

mosz-8a Manus-Oceanic Convergent Boundary 149.3226 -1.6666 117.8 15 17.83

mosz-8b Manus-Oceanic Convergent Boundary 149.5251 -1.2829 117.8 15 4.89

mosz-9a Manus-Oceanic Convergent Boundary 148.5865 -1.3017 112.7 15 17.84

mosz-9b Manus-Oceanic Convergent Boundary 148.7540 -0.9015 112.7 15 4.9

mosz-10a Manus-Oceanic Convergent Boundary 147.7760 -1.1560 108 15 17.78

mosz-10b Manus-Oceanic Convergent Boundary 147.9102 -0.7434 108 15 4.84

mosz-11a Manus-Oceanic Convergent Boundary 146.9596 -1.1226 102.5 15 17.54

mosz-11b Manus-Oceanic Convergent Boundary 147.0531 -0.6990 102.5 15 4.6

mosz-12a Manus-Oceanic Convergent Boundary 146.2858 -1.1820 87.48 15 17.29

mosz-12b Manus-Oceanic Convergent Boundary 146.2667 -0.7486 87.48 15 4.35

mosz-13a Manus-Oceanic Convergent Boundary 145.4540 -1.3214 83.75 15 17.34

mosz-13b Manus-Oceanic Convergent Boundary 145.4068 -0.8901 83.75 15 4.4

mosz-14a Manus-Oceanic Convergent Boundary 144.7151 -1.5346 75.09 15 17.21

mosz-14b Manus-Oceanic Convergent Boundary 144.6035 -1.1154 75.09 15 4.27

mosz-15a Manus-Oceanic Convergent Boundary 143.9394 -1.8278 70.43 15 16.52

mosz-15b Manus-Oceanic Convergent Boundary 143.7940 -1.4190 70.43 15 3.58

mosz-16a Manus-Oceanic Convergent Boundary 143.4850 -2.2118 50.79 15 15.86

mosz-16b Manus-Oceanic Convergent Boundary 143.2106 -1.8756 50.79 15 2.92

mosz-17a Manus-Oceanic Convergent Boundary 143.1655 -2.7580 33 15 16.64

mosz-17b Manus-Oceanic Convergent Boundary 142.8013 -2.5217 33 15 3.7

Table B6: Earthquake parameters for Manus–Oceanic Convergent Boundary Subduction Zone unit

sources.
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 137 Figure B7: New Guinea Subduction Zone unit sources. 130°E 135°E 140°E 145°E 150°E

 0°

 3°S

 6°S

 9°S 3°N 1 3 5 7 9 11 13 15 b, a
138 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

ngsz-1a New Guinea 143.6063 -4.3804 120 29 25.64

ngsz-1b New Guinea 143.8032 -4.0402 120 29 1.4

ngsz-2a New Guinea 142.9310 -3.9263 114 27.63 20.1

ngsz-2b New Guinea 143.0932 -3.5628 114 21.72 1.6

ngsz-3a New Guinea 142.1076 -3.5632 114 20.06 18.73

ngsz-3b New Guinea 142.2795 -3.1778 114 15.94 5

ngsz-4a New Guinea 141.2681 -3.2376 114 21 17.76

ngsz-4b New Guinea 141.4389 -2.8545 114 14.79 5

ngsz-5a New Guinea 140.4592 -2.8429 114 21.26 16.14

ngsz-5b New Guinea 140.6296 -2.4605 114 12.87 5

ngsz-6a New Guinea 139.6288 -2.4960 114 22.72 15.4

ngsz-6b New Guinea 139.7974 -2.1175 114 12 5

ngsz-7a New Guinea 138.8074 -2.1312 114 21.39 15.4

ngsz-7b New Guinea 138.9776 -1.7491 114 12 5

ngsz-8a New Guinea 138.0185 -1.7353 113.1 18.79 15.14

ngsz-8b New Guinea 138.1853 -1.3441 113.1 11.7 5

ngsz-9a New Guinea 137.1805 -1.5037 111 15.24 13.23

ngsz-9b New Guinea 137.3358 -1.0991 111 9.47 5

ngsz-10a New Guinea 136.3418 -1.1774 111 13.51 11.09

ngsz-10b New Guinea 136.4983 -0.7697 111 7 5

ngsz-11a New Guinea 135.4984 -0.8641 111 11.38 12.49

ngsz-11b New Guinea 135.6562 -0.4530 111 8.62 5

ngsz-12a New Guinea 134.6759 -0.5216 110.5 10 13.68

ngsz-12b New Guinea 134.8307 -0.1072 110.5 10 5

ngsz-13a New Guinea 133.3065 -1.0298 99.5 10 13.68

ngsz-13b New Guinea 133.3795 -0.5935 99.5 10 5

ngsz-14a New Guinea 132.4048 -0.8816 99.5 10 13.68

ngsz-14b New Guinea 132.4778 -0.4453 99.5 10 5

ngsz-15a New Guinea 131.5141 -0.7353 99.5 10 13.68

ngsz-15b New Guinea 131.5871 -0.2990 99.5 10 5

Table B7: Earthquake parameters for New Guinea Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 139 

Figure B8: New Zealand–Kermadec–Tonga Subduction Zone unit sources.

 175°E 180°W 175°W 170°W

 42°S

 36°S

 30°S

 24°S

 18°S

5

10

15

20

25

30

35

a,

b,

c
140 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

ntsz-1a New Zealand–Kermadec–Tonga 174.0985 -41.3951 258.6 24 25.34

ntsz-1b New Zealand–Kermadec–Tonga 174.2076 -41.7973 258.6 24 5

ntsz-2a New Zealand–Kermadec–Tonga 175.3289 -41.2592 260.6 29.38 23.17

ntsz-2b New Zealand–Kermadec–Tonga 175.4142 -41.6454 260.6 21.31 5

ntsz-3a New Zealand–Kermadec–Tonga 176.2855 -40.9950 250.7 29.54 21.74

ntsz-3b New Zealand–Kermadec–Tonga 176.4580 -41.3637 250.7 19.56 5

ntsz-4a New Zealand–Kermadec–Tonga 177.0023 -40.7679 229.4 24.43 18.87

ntsz-4b New Zealand–Kermadec–Tonga 177.3552 -41.0785 229.4 16.1 5

ntsz-5a New Zealand–Kermadec–Tonga 177.4114 -40.2396 210 18.8 19.29

ntsz-5b New Zealand–Kermadec–Tonga 177.8951 -40.4525 210 16.61 5

ntsz-6a New Zealand–Kermadec–Tonga 177.8036 -39.6085 196.7 18.17 15.8

ntsz-6b New Zealand–Kermadec–Tonga 178.3352 -39.7310 196.7 12.48 5

ntsz-7a New Zealand–Kermadec–Tonga 178.1676 -38.7480 197 28.1 17.85

ntsz-7b New Zealand–Kermadec–Tonga 178.6541 -38.8640 197 14.89 5

ntsz-8a New Zealand–Kermadec–Tonga 178.6263 -37.8501 201.4 31.47 18.78

ntsz-8b New Zealand–Kermadec–Tonga 179.0788 -37.9899 201.4 16 5

ntsz-9a New Zealand–Kermadec–Tonga 178.9833 -36.9770 202.2 29.58 20.02

ntsz-9b New Zealand–Kermadec–Tonga 179.4369 -37.1245 202.2 17.48 5

ntsz-10a New Zealand–Kermadec–Tonga 179.5534 -36.0655 210.6 32.1 20.72

ntsz-10b New Zealand–Kermadec–Tonga 179.9595 -36.2593 210.6 18.32 5

ntsz-11a New Zealand–Kermadec–Tonga 179.9267 -35.3538 201.7 25 16.09

ntsz-11b New Zealand–Kermadec–Tonga 180.3915 -35.5040 201.7 12.81 5

ntsz-12a New Zealand–Kermadec–Tonga 180.4433 -34.5759 201.2 25 15.46

ntsz-12b New Zealand–Kermadec–Tonga 180.9051 -34.7230 201.2 12.08 5

ntsz-13a New Zealand–Kermadec–Tonga 180.7990 -33.7707 199.8 25.87 19.06

ntsz-13b New Zealand–Kermadec–Tonga 181.2573 -33.9073 199.8 16.33 5

ntsz-14a New Zealand–Kermadec–Tonga 181.2828 -32.9288 202.4 31.28 22.73

ntsz-14b New Zealand–Kermadec–Tonga 181.7063 -33.0751 202.4 20.77 5

ntsz-15a New Zealand–Kermadec–Tonga 181.4918 -32.0035 205.4 32.33 22.64

ntsz-15b New Zealand–Kermadec–Tonga 181.8967 -32.1665 205.4 20.66 5

ntsz-16a New Zealand–Kermadec–Tonga 181.9781 -31.2535 205.5 34.29 23.59

ntsz-16b New Zealand–Kermadec–Tonga 182.3706 -31.4131 205.5 21.83 5

ntsz-17a New Zealand–Kermadec–Tonga 182.4819 -30.3859 210.3 37.6 25.58

ntsz-17b New Zealand–Kermadec–Tonga 182.8387 -30.5655 210.3 24.3 5

ntsz-18a New Zealand–Kermadec–Tonga 182.8176 -29.6545 201.6 37.65 26.13

ntsz-18b New Zealand–Kermadec–Tonga 183.1985 -29.7856 201.6 25 5

ntsz-19a New Zealand–Kermadec–Tonga 183.0622 -28.8739 195.7 34.41 26.13

ntsz-19b New Zealand–Kermadec–Tonga 183.4700 -28.9742 195.7 25 5

ntsz-20a New Zealand–Kermadec–Tonga 183.2724 -28.0967 188.8 38 26.13

ntsz-20b New Zealand–Kermadec–Tonga 183.6691 -28.1508 188.8 25 5

continued on next page

Table B8: Earthquake parameters for New Zealand–Kermadec–Tonga Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 141 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

ntsz-21a New Zealand–Kermadec–Tonga 183.5747 -27.1402 197.1 32.29 24.83

ntsz-21b New Zealand–Kermadec–Tonga 183.9829 -27.2518 197.1 23.37 5

ntsz-22a New Zealand–Kermadec–Tonga 183.6608 -26.4975 180 29.56 18.63

ntsz-22b New Zealand–Kermadec–Tonga 184.0974 -26.4975 180 15.82 5

ntsz-23a New Zealand–Kermadec–Tonga 183.7599 -25.5371 185.8 32.42 20.56

ntsz-23b New Zealand–Kermadec–Tonga 184.1781 -25.5752 185.8 18.13 5

ntsz-24a New Zealand–Kermadec–Tonga 183.9139 -24.6201 188.2 33.31 23.73

ntsz-24b New Zealand–Kermadec–Tonga 184.3228 -24.6734 188.2 22 5

ntsz-25a New Zealand–Kermadec–Tonga 184.1266 -23.5922 198.5 29.34 19.64

ntsz-25b New Zealand–Kermadec–Tonga 184.5322 -23.7163 198.5 17.03 5

ntsz-26a New Zealand–Kermadec–Tonga 184.6613 -22.6460 211.7 30.26 19.43

ntsz-26b New Zealand–Kermadec–Tonga 185.0196 -22.8497 211.7 16.78 5

ntsz-27a New Zealand–Kermadec–Tonga 185.0879 -21.9139 207.9 31.73 20.67

ntsz-27b New Zealand–Kermadec–Tonga 185.4522 -22.0928 207.9 18.27 5

ntsz-28a New Zealand–Kermadec–Tonga 185.4037 -21.1758 200.5 32.44 21.76

ntsz-28b New Zealand–Kermadec–Tonga 185.7849 -21.3084 200.5 19.58 5

ntsz-29a New Zealand–Kermadec–Tonga 185.8087 -20.2629 206.4 32.47 20.4

ntsz-29b New Zealand–Kermadec–Tonga 186.1710 -20.4312 206.4 17.94 5

ntsz-30a New Zealand–Kermadec–Tonga 186.1499 -19.5087 200.9 32.98 22.46

ntsz-30b New Zealand–Kermadec–Tonga 186.5236 -19.6432 200.9 20.44 5

ntsz-31a New Zealand–Kermadec–Tonga 186.3538 -18.7332 193.9 34.41 21.19

ntsz-31b New Zealand–Kermadec–Tonga 186.7339 -18.8221 193.9 18.89 5

ntsz-32a New Zealand–Kermadec–Tonga 186.5949 -17.8587 194.1 30 19.12

ntsz-32b New Zealand–Kermadec–Tonga 186.9914 -17.9536 194.1 16.4 5

ntsz-33a New Zealand–Kermadec–Tonga 186.8172 -17.0581 190 33.15 23.34

ntsz-33b New Zealand–Kermadec–Tonga 187.2047 -17.1237 190 21.52 5

ntsz-34a New Zealand–Kermadec–Tonga 186.7814 -16.2598 182.1 15 13.41

ntsz-34b New Zealand–Kermadec–Tonga 187.2330 -16.2759 182.1 9.68 5

ntsz-34c New Zealand–Kermadec–Tonga 187.9697 -16.4956 7.62 57.06 6.571

ntsz-35a New Zealand–Kermadec–Tonga 186.8000 -15.8563 149.8 15 12.17

ntsz-35b New Zealand–Kermadec–Tonga 187.1896 -15.6384 149.8 8.24 5

ntsz-35c New Zealand–Kermadec–Tonga 187.8776 -15.6325 342.4 57.06 6.571

ntsz-36a New Zealand–Kermadec–Tonga 186.5406 -15.3862 123.9 40.44 36.72

ntsz-36b New Zealand–Kermadec–Tonga 186.7381 -15.1025 123.9 39.38 5

ntsz-36c New Zealand–Kermadec–Tonga 187.3791 -14.9234 307 57.06 6.571

ntsz-37a New Zealand–Kermadec–Tonga 185.9883 -14.9861 102 68.94 30.99

ntsz-37b New Zealand–Kermadec–Tonga 186.0229 -14.8282 102 31.32 5

ntsz-38a New Zealand–Kermadec–Tonga 185.2067 -14.8259 88.4 80 26.13

ntsz-38b New Zealand–Kermadec–Tonga 185.2044 -14.7479 88.4 25 5

ntsz-39a New Zealand–Kermadec–Tonga 184.3412 -14.9409 82.55 80 26.13

ntsz-39b New Zealand–Kermadec–Tonga 184.3307 -14.8636 82.55 25 5

Table B8: (continued)

PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 143 Figure B9: New Britain–Solomons–Vanuatu Subduction Zone unit sources.

 150°E 156°E 162°E 168°E 174°E

 25°S

 20°S

 15°S

 5°S

 10°S

1

5

10

15

20

25

30

35

a,b
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 145 

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

nvsz-20b New Britain–Solomons–Vanuatu 163.7581 -10.7858 262.9 25.22 5

nvsz-21a New Britain–Solomons–Vanuatu 164.9445 -10.4183 287.9 40.31 23.3

nvsz-21b New Britain–Solomons–Vanuatu 164.8374 -10.7442 287.9 21.47 5

nvsz-22a New Britain–Solomons–Vanuatu 166.0261 -11.1069 317.1 42.39 20.78

nvsz-22b New Britain–Solomons–Vanuatu 165.7783 -11.3328 317.1 18.4 5

nvsz-23a New Britain–Solomons–Vanuatu 166.5179 -12.2260 342.4 47.95 22.43

nvsz-23b New Britain–Solomons–Vanuatu 166.2244 -12.3171 342.4 20.4 5

nvsz-24a New Britain–Solomons–Vanuatu 166.7236 -13.1065 342.6 47.13 28.52

nvsz-24b New Britain–Solomons–Vanuatu 166.4241 -13.1979 342.6 28.06 5

nvsz-25a New Britain–Solomons–Vanuatu 166.8914 -14.0785 350.3 54.1 31.16

nvsz-25b New Britain–Solomons–Vanuatu 166.6237 -14.1230 350.3 31.55 5

nvsz-26a New Britain–Solomons–Vanuatu 166.9200 -15.1450 365.6 50.46 29.05

nvsz-26b New Britain–Solomons–Vanuatu 166.6252 -15.1170 365.6 28.75 5

nvsz-27a New Britain–Solomons–Vanuatu 167.0053 -15.6308 334.2 44.74 25.46

nvsz-27b New Britain–Solomons–Vanuatu 166.7068 -15.7695 334.2 24.15 5

nvsz-28a New Britain–Solomons–Vanuatu 167.4074 -16.3455 327.5 41.53 22.44

nvsz-28b New Britain–Solomons–Vanuatu 167.1117 -16.5264 327.5 20.42 5

nvsz-29a New Britain–Solomons–Vanuatu 167.9145 -17.2807 341.2 49.1 24.12

nvsz-29b New Britain–Solomons–Vanuatu 167.6229 -17.3757 341.2 22.48 5

nvsz-30a New Britain–Solomons–Vanuatu 168.2220 -18.2353 348.6 44.19 23.99

nvsz-30b New Britain–Solomons–Vanuatu 167.8895 -18.2991 348.6 22.32 5

nvsz-31a New Britain–Solomons–Vanuatu 168.5022 -19.0510 345.6 42.2 22.26

nvsz-31b New Britain–Solomons–Vanuatu 168.1611 -19.1338 345.6 20.2 5

nvsz-32a New Britain–Solomons–Vanuatu 168.8775 -19.6724 331.1 42.03 21.68

nvsz-32b New Britain–Solomons–Vanuatu 168.5671 -19.8338 331.1 19.49 5

nvsz-33a New Britain–Solomons–Vanuatu 169.3422 -20.4892 332.9 40.25 22.4

nvsz-33b New Britain–Solomons–Vanuatu 169.0161 -20.6453 332.9 20.37 5

nvsz-34a New Britain–Solomons–Vanuatu 169.8304 -21.2121 329.1 39 22.73

nvsz-34b New Britain–Solomons–Vanuatu 169.5086 -21.3911 329.1 20.77 5

nvsz-35a New Britain–Solomons–Vanuatu 170.3119 -21.6945 311.9 39 22.13

nvsz-35b New Britain–Solomons–Vanuatu 170.0606 -21.9543 311.9 20.03 5

nvsz-36a New Britain–Solomons–Vanuatu 170.9487 -22.1585 300.4 39.42 23.5

nvsz-36b New Britain–Solomons–Vanuatu 170.7585 -22.4577 300.4 21.71 5

nvsz-37a New Britain–Solomons–Vanuatu 171.6335 -22.3087 281.3 30 22.1

nvsz-37b New Britain–Solomons–Vanuatu 171.5512 -22.6902 281.3 20 5

Table B9: (continued)

144 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

nvsz-1a New Britain–Solomons–Vanuatu 148.6217 -6.4616 243.2 32.34 15.69

nvsz-1b New Britain–Solomons–Vanuatu 148.7943 -6.8002 234.2 12.34 5

nvsz-2a New Britain–Solomons–Vanuatu 149.7218 -6.1459 260.1 35.1 16.36

nvsz-2b New Britain–Solomons–Vanuatu 149.7856 -6.5079 260.1 13.13 5

nvsz-3a New Britain–Solomons–Vanuatu 150.4075 -5.9659 245.7 42.35 18.59

nvsz-3b New Britain–Solomons–Vanuatu 150.5450 -6.2684 245.7 15.77 5

nvsz-4a New Britain–Solomons–Vanuatu 151.1095 -5.5820 238.2 42.41 23.63

nvsz-4b New Britain–Solomons–Vanuatu 151.2851 -5.8639 238.2 21.88 5

nvsz-5a New Britain–Solomons–Vanuatu 152.0205 -5.1305 247.7 49.22 32.39

nvsz-5b New Britain–Solomons–Vanuatu 152.1322 -5.4020 247.7 33.22 5

nvsz-6a New Britain–Solomons–Vanuatu 153.3450 -5.1558 288.6 53.53 33.59

nvsz-6b New Britain–Solomons–Vanuatu 153.2595 -5.4089 288.6 34.87 5

nvsz-7a New Britain–Solomons–Vanuatu 154.3814 -5.6308 308.3 39.72 19.18

nvsz-7b New Britain–Solomons–Vanuatu 154.1658 -5.9017 308.3 16.48 5

nvsz-8a New Britain–Solomons–Vanuatu 155.1097 -6.3511 317.2 45.33 22.92

nvsz-8b New Britain–Solomons–Vanuatu 154.8764 -6.5656 317.2 21 5

nvsz-9a New Britain–Solomons–Vanuatu 155.5027 -6.7430 290.5 48.75 22.92

nvsz-9b New Britain–Solomons–Vanuatu 155.3981 -7.0204 290.5 21 5

nvsz-10a New Britain–Solomons–Vanuatu 156.4742 -7.2515 305.9 36.88 27.62

nvsz-10b New Britain–Solomons–Vanuatu 156.2619 -7.5427 305.9 26.9 5

nvsz-11a New Britain–Solomons–Vanuatu 157.0830 -7.8830 305.4 32.97 29.72

nvsz-11b New Britain–Solomons–Vanuatu 156.8627 -8.1903 305.4 29.63 5

nvsz-12a New Britain–Solomons–Vanuatu 157.6537 -8.1483 297.9 37.53 28.57

nvsz-12b New Britain–Solomons–Vanuatu 157.4850 -8.4630 297.9 28.13 5

nvsz-13a New Britain–Solomons–Vanuatu 158.5089 -8.5953 302.7 33.62 23.02

nvsz-13b New Britain–Solomons–Vanuatu 158.3042 -8.9099 302.7 21.12 5

nvsz-14a New Britain–Solomons–Vanuatu 159.1872 -8.9516 293.3 38.44 34.06

nvsz-14b New Britain–Solomons–Vanuatu 159.0461 -9.2747 293.3 35.54 5

nvsz-15a New Britain–Solomons–Vanuatu 159.9736 -9.5993 302.8 46.69 41.38

nvsz-15b New Britain–Solomons–Vanuatu 159.8044 -9.8584 302.8 46.69 5

nvsz-16a New Britain–Solomons–Vanuatu 160.7343 -10.0574 301 46.05 41

nvsz-16b New Britain–Solomons–Vanuatu 160.5712 -10.3246 301 46.05 5

nvsz-17a New Britain–Solomons–Vanuatu 161.4562 -10.5241 298.4 40.12 37.22

nvsz-17b New Britain–Solomons–Vanuatu 161.2900 -10.8263 298.4 40.12 5

nvsz-18a New Britain–Solomons–Vanuatu 162.0467 -10.6823 274.1 40.33 29.03

nvsz-18b New Britain–Solomons–Vanuatu 162.0219 -11.0238 274.1 28.72 5

nvsz-19a New Britain–Solomons–Vanuatu 162.7818 -10.5645 261.3 34.25 24.14

nvsz-19b New Britain–Solomons–Vanuatu 162.8392 -10.9315 261.3 22.51 5

nvsz-20a New Britain–Solomons–Vanuatu 163.7222 -10.5014 262.9 50.35 26.3

continued on next page

Table B9: Earthquake parameters for New Britain–Solomons–Vanuatu Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 147 

Figure B10: New Zealand–Puysegur Subduction Zone unit sources.

 160°E 164°E 168°E 172°E 176°E 180°W

 52°S

 48°S

 44°S

 40°S

 36°S

1

3

5

7

b, a
148 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

nzsz-1a New Zealand–Puysegur 168.0294 -45.4368 41.5 15 17.94

nzsz-1b New Zealand–Puysegur 167.5675 -45.1493 41.5 15 5

nzsz-2a New Zealand–Puysegur 167.3256 -46.0984 37.14 15 17.94

nzsz-2b New Zealand–Puysegur 166.8280 -45.8365 37.14 15 5

nzsz-3a New Zealand–Puysegur 166.4351 -46.7897 39.53 15 17.94

nzsz-3b New Zealand–Puysegur 165.9476 -46.5136 39.53 15 5

nzsz-4a New Zealand–Puysegur 166.0968 -47.2583 15.38 15 17.94

nzsz-4b New Zealand–Puysegur 165.4810 -47.1432 15.38 15 5

nzsz-5a New Zealand–Puysegur 165.7270 -48.0951 13.94 15 17.94

nzsz-5b New Zealand–Puysegur 165.0971 -47.9906 13.94 15 5

nzsz-6a New Zealand–Puysegur 165.3168 -49.0829 22.71 15 17.94

nzsz-6b New Zealand–Puysegur 164.7067 -48.9154 22.71 15 5

nzsz-7a New Zealand–Puysegur 164.8017 -49.9193 23.25 15 17.94

nzsz-7b New Zealand–Puysegur 164.1836 -49.7480 23.25 15 5

Table B10: Earthquake parameters for New Zealand–Puysegur Subduction Zone unit sources.
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 149 Figure B11: Ryukyu–Kyushu–Nankai Subduction Zone unit sources. 120°E 125°E 130°E 135°E 140°E 21°N 24°N

 27°N

 30°N

 33°N

 36°N

1 3

5

7

9

11

13

15

17

19

21

a,b
150 Spillane

Segment Description

Longitude

(°E)

Latitude

(°N)

Strike

(°)

Dip

(°)

Depth 

(km)

rnsz-1a Ryukyu–Kyushu–Nankai 122.6672 23.6696 262 14 11.88

rnsz-1b Ryukyu–Kyushu–Nankai 122.7332 23.2380 262 10 3.2

rnsz-2a Ryukyu–Kyushu–Nankai 123.5939 23.7929 259.9 18.11 12.28

rnsz-2b Ryukyu–Kyushu–Nankai 123.6751 23.3725 259.9 10 3.6

rnsz-3a Ryukyu–Kyushu–Nankai 124.4604 23.9777 254.6 19.27 14.65

rnsz-3b Ryukyu–Kyushu–Nankai 124.5830 23.5689 254.6 12.18 4.1

rnsz-4a Ryukyu–Kyushu–Nankai 125.2720 24.2102 246.8 18 20.38

rnsz-4b Ryukyu–Kyushu–Nankai 125.4563 23.8177 246.8 16 6.6

rnsz-5a Ryukyu–Kyushu–Nankai 125.9465 24.5085 233.6 18 20.21

rnsz-5b Ryukyu–Kyushu–Nankai 126.2241 24.1645 233.6 16 6.43

rnsz-6a Ryukyu–Kyushu–Nankai 126.6349 25.0402 228.7 17.16 19.55

rnsz-6b Ryukyu–Kyushu–Nankai 126.9465 24.7176 228.7 15.16 6.47

rnsz-7a Ryukyu–Kyushu–Nankai 127.2867 25.6343 224 15.85 17.98

rnsz-7b Ryukyu–Kyushu–Nankai 127.6303 25.3339 224 13.56 6.26

rnsz-8a Ryukyu–Kyushu–Nankai 128.0725 26.3146 229.7 14.55 14.31

rnsz-8b Ryukyu–Kyushu–Nankai 128.3854 25.9831 229.7 9.64 5.94

rnsz-9a Ryukyu–Kyushu–Nankai 128.6642 26.8177 219.2 15.4 12.62

rnsz-9b Ryukyu–Kyushu–Nankai 129.0391 26.5438 219.2 8 5.66

rnsz-10a Ryukyu–Kyushu–Nankai 129.2286 27.4879 215.2 17 12.55

rnsz-10b Ryukyu–Kyushu–Nankai 129.6233 27.2402 215.2 8.16 5.45

rnsz-11a Ryukyu–Kyushu–Nankai 129.6169 28.0741 201.3 17 12.91

rnsz-11b Ryukyu–Kyushu–Nankai 130.0698 27.9181 201.3 8.8 5.26

rnsz-12a Ryukyu–Kyushu–Nankai 130.6175 29.0900 236.7 16.42 13.05

rnsz-12b Ryukyu–Kyushu–Nankai 130.8873 28.7299 236.7 9.57 4.74

rnsz-13a Ryukyu–Kyushu–Nankai 130.7223 29.3465 195.2 20.25 15.89

rnsz-13b Ryukyu–Kyushu–Nankai 131.1884 29.2362 195.2 12.98 4.66

rnsz-14a Ryukyu–Kyushu–Nankai 131.3467 30.3899 215.1 22.16 19.73

rnsz-14b Ryukyu–Kyushu–Nankai 131.7402 30.1507 215.1 17.48 4.71

rnsz-15a Ryukyu–Kyushu–Nankai 131.9149 31.1450 216 15.11 16.12

rnsz-15b Ryukyu–Kyushu–Nankai 132.3235 30.8899 216 13.46 4.48

rnsz-16a Ryukyu–Kyushu–Nankai 132.5628 31.9468 220.9 10.81 10.88

rnsz-16b Ryukyu–Kyushu–Nankai 132.9546 31.6579 220.9 7.19 4.62

rnsz-17a Ryukyu–Kyushu–Nankai 133.6125 32.6956 239 10.14 12.01

rnsz-17b Ryukyu–Kyushu–Nankai 133.8823 32.3168 239 8.41 4.7

rnsz-18a Ryukyu–Kyushu–Nankai 134.6416 33.1488 244.7 10.99 14.21

rnsz-18b Ryukyu–Kyushu–Nankai 134.8656 32.7502 244.5 10.97 4.7

rnsz-19a Ryukyu–Kyushu–Nankai 135.6450 33.5008 246.5 14.49 14.72

rnsz-19b Ryukyu–Kyushu–Nankai 135.8523 33.1021 246.5 11.87 4.44

rnsz-20a Ryukyu–Kyushu–Nankai 136.5962 33.8506 244.8 15 14.38

rnsz-20b Ryukyu–Kyushu–Nankai 136.8179 33.4581 244.8 12 3.98

rnsz-21a Ryukyu–Kyushu–Nankai 137.2252 34.3094 231.9 15 15.4

rnsz-21b Ryukyu–Kyushu–Nankai 137.5480 33.9680 231.9 12 5

rnsz-22a Ryukyu–Kyushu–Nankai 137.4161 34.5249 192.3 15 15.4

rnsz-22b Ryukyu–Kyushu–Nankai 137.9301 34.4327 192.3 12 5

Table B11: Earthquake parameters for Ryukyu–Kyushu–Nankai Subduction Zone unit sources.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 151 

Appendix C. 

Synthetic Testing: Point Reyes, California*

C1. Purpose

Forecast models are tested with synthetic tsunami events covering a range of

tsunami source locations and magnitudes ranging from mega-tsunami events

to micro-tsunami events. Testing is also done with selected historical tsunami

events when available.

The purpose of forecast model testing is three-fold. The first objective is to

assure that the results obtained with NOAA’s tsunami forecast system, which has

been released to the Tsunami Warning Centers for operational use, are consistent with those obtained by the researcher during the development of the forecast

model. The second objective is to test the forecast model for consistency, accuracy,

time efficiency, and quality of results over a range of possible tsunami locations

and magnitudes. The third objective is to identify bugs and issues in need of resolution by the researcher who developed the forecast model or by the forecast software development team before the next version release to NOAA’s two Tsunami

Warning Centers.

Local hardware and software applications are used with tools familiar to the

researcher(s) to run the Method of Splitting Tsunami (MOST) model during the 

forecast model development. The test results presented in this report lend confidence that the model performs as developed and produces the same results when

initiated within the forecast application in an operational setting as those produced

by the researcher during the forecast model development. The test results assure

those who rely on the tsunami forecast model for Point Reyes, California, that

consistent results are produced irrespective of system.

C2. Testing procedure

The general procedure for forecast model testing is to run a set of synthetic 

tsunami scenarios and a selected set of historical tsunami events through the 

forecast system application, and compare the results with those obtained by the

researcher during the forecast model development (as presented in the Tsunami 

Forecast Model Report). Specific steps taken to test the model include:

1. Identification of testing scenarios, including the standard set of synthetic events,

appropriate historical events, and customized synthetic scenarios that may have

been used by the researcher(s) in the development of the forecast model.

2. Creation of new events to represent customized synthetic scenarios used by the

researcher(s) in the development of the forecast model, if any.

3. Submission of test model runs with the forecast system, and export of the

results from A, B, and C grids, along with time series.

* Authors: Mick Spillane, Lindsey Wright
152 Spillane.

4. Recording applicable metadata, including the specific version of the forecast

system used for testing.

5. Examination of forecast system model results for instabilities in both time series

and plot results.

6. Comparison of forecast model results obtained through the forecast system with

those obtained during the forecast model development.

7. Summarization of results with specific mention of quality, consistency, and time

efficiency.

8. Reporting of issues identified to modeler and forecast software development team.

9. Retesting the forecast models in the forecast system when reported issues have

been addressed or explained.

Synthetic model runs were tested on a DELL PowerEdge R510 computer

equipped with two Xeon E5670 processors at 2.93 GHz, each with 12 MBytes of

cache and 32 GB memory. The processors are hex core and support hyperthreading,

resulting in the computer performing as a 24 processor core machine. Additionally,

the testing computer supports 10 Gigabit Ethernet for fast network connections.

This computer configuration is similar or the same as the configurations of the

computers installed at the Tsunami Warning Centers so the compute times should 

only vary slightly.

C3. Results

The Point Reyes forecast model was tested with five synthetic scenarios and one

historicaltsunami event.Test results fromthe forecast systemandcomparisonswith

the results obtained during the forecast model development are shown numerically

in Table C1 and graphically in Figures C1–C6. The results show that the forecast

modelis stable and robust,with consistent and high-quality results across geographically distributed tsunami sources and mega-tsunami event magnitudes. The model 

run time (wall-clock time) was under 18 min for 8 hr of simulation time, and under 8

min for 4.0 hr, thereby satisfying the required time criterion of 10 min run time per

4 hr of simulation time for operational efficiency.

Time series plots for two of the synthetic cases (CSSZ 89–98 and KISZ 22–31)

were not present in the main report and their statistics were extracted from the

original model output files from the development stage. The modeled scenarios were

stable for all cases tested, with no instabilities or ringing. Results show that the

largest modeled height was 401.25 cm, originating in the New Zealand-KermadecTonga (NTSZ 30–39) source. Amplitudes greater than 100 cm were recorded for

all synthetic test sources. The smallest signal of 119.8 cm was recorded for the

far-field Central and South American (CSSZ 89–98) source. Direct comparisons of

output from the forecast tool with results of the historical event (Tohoku, previously

referred to as 2011 Honshu in this report) and available development synthetic

events demonstrated that the wave patterns were similar in shape, pattern, and

amplitude.
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 153 

Table C1: Maximum and minimum amplitudes (cm) at the Point Reyes, California, warning point for synthetic and historical events tested usingSIFT 3.2 and obtained during development.

Maxima (cm) Minima (cm)

Scenarios Source Zone Tsunami Source α [m] SIFT Development SIFT Development 

Mega-tsunami Scenarios

KISZ 1–10 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A1–10, B1–10 25 354.127 354 -175.953 -219KISZ 22–31 Kamchatka-Kuril-Japan-Izu-Mariana-Yap A22–31, B22–31 25 250.248 251 -176.243 -214ACSZ 56–65 Aleutian-Alaska-Cascadia A56–65, B56–65 25 157.536 159 -158.122 -156CSSZ 89–98 Central and South America A89–98, B89–98 25 119.796 119 -141.905 -142NTSZ 30–39 New Zealand-Kermadec-Tonga A30–39, B30–39 25 401.252 402 -177.000 -219

Historical Event

2011 Tohoku Kamchatka-Kuril-Japan-Izu-Mariana-Yap 4.66 b24 + 12.23 b25 +

26.31 a26 +21.27 b26 +

22.75 a27 + 4.98 b27

178.215 182 -148.389 -136
154 Spillane. Figure C1: Response of the Point Reyes forecast model to synthetic scenario KISZ 1-10 (α=25). Maximum sea surface elevation for (a) A grid, (b) B grid, and (c) C grid. Sea surface elevation time series at the C-grid warning point (d). The extrema at the reference point are compared with the equivalent values obtained during model development in Figure 12.
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 155 Figure C2: Response of the Point Reyes forecast model to synthetic scenario KISZ 22-31 (α=25). Maximum sea surface elevation for (a) A grid, (b) B grid, and (c) C grid. Sea surface elevation time series at the C-grid warning point (d). The extrema at the reference point are compared with the equivalent values obtained during model development listed in Table C1.
156 Spillane. Figure C3: Response of the Point Reyes forecast model to synthetic scenario ACSZ 56–65 (α=25). Maximum sea surface elevation for (a) A grid, (b) B grid, and (c) C grid. Sea surface elevation time series at the C-grid warning point (d). Panels (c) and (d) can be compared with the equivalent results, obtained during model development, displayed in Figure 11. 
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 157 Figure C4: Response of the Point Reyes forecast model to synthetic scenario CSSZ 89–98 (α=25). Maximum sea surface elevation for (a) A grid, (b) B grid, and (c) C grid. Sea surface elevation time series at the C-grid warning point (d). Panels (c) and (d) can be compared with the equivalent results, obtained during model development, listed in Table C1.
158 Spillane. Figure C5: Response of the Point Reyes forecast model to synthetic scenario NTSZ 30–39 (α=25). Maximum sea surface elevation for (a) A grid, (b) B grid, (c) C grid. Sea surface elevation time series at the C-grid warning point (d). Panels (c) and (d) can be compared with the equivalent results, obtained during model development, displayed in Figure 13. 
PMEL Tsuna

mi ForecastSeries: Vol. 6—PointReyes, California 159 Figure C6: Response of the Poiint Reyes forecast model to the 11 March 2011 Tohoku (Honshu) tsunami. Maximum sea surface elevation for (a) A-grid, (b) B-grid, and (c) C-grid. Sea surface elevation time series at the C-grid warning point (d). Panels (c) and (d) can be compared with the equivalent results, obtained during model development, displayed in Figures 17(a) and 16, respectively.

PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 161 

Glossary

Arrival time  The time when the first tsunami wave is observed at a particular location, typically given in local and/or universal time, but also commonly

noted in minutes or hours relative to the time of the earthquake.

Bathymetry  The measurement of water depth of an undisturbed body of

water.

Cascadia Subduction Zone  Fault that extends from Cape Mendocino in

Northern California northward to mid-Vancouver Island, Canada. The fault

marks the convergence boundary where the Juan de Fuca tectonic plate is being subducted under the margin of the North America plate.

Current speed  The scalar rate of water motion measured as distance/time.

Current velocity  Movement of water expressed as a vector quantity. Velocity

is the distance of movement per time coupled with direction of motion.

Deep-ocean Assessment and Reporting of Tsunamis (DART®) Tsunami 

detection and transmission system that measures the pressure of an overlying 

column of water and detects the passage of a tsunami.

Digital Elevation Model (DEM)  A digital representation of bathymetry

or topography based on regional survey data or satellite imagery. Data are

arrays of regularly spaced elevations referenced to a map projection of the

geographic coordinate system.

Epicenter  The point on the surface of the earth that is directly above the

focus of an earthquake.

Far-field  Region outside of the source of a tsunami where no direct observations of the tsunami-generating event are evident, except for the tsunami

waves themselves.

Focus  The point beneath the surface of the earth where a rupture or energy

release occurs due to a buildup of stress or the movement of Earth’s tectonic

plates relative to one another.

Inundation  The horizontal inland extent of land that a tsunami penetrates,

generally measured perpendicularly to a shoreline.

Marigram  Tide gauge recording of wave level as a function of time at a particular location. The instrument used for recording is termed a marigraph.

Method of Splitting Tsunami (MOST) A suite of numerical simulation 

codes used to provide estimates of the three processes of tsunami evolution: 

tsunami generation, propagation, and inundation. 
162 Spillane.

Moment magnitude (Mw)  The magnitude of an earthquake on a logarithmic

scale in terms of the energy released. Moment magnitude is based on the size

and characteristics of a fault rupture as determined from long-period seismic

waves.

Near–field Region of primary tsunami impact near the source of a tsunami. 

The near-field is defined as the region where non-tsunami effects of the tsunami-generating event have been observed, such as earth shaking from the

earthquake, visible or measured ground deformation, or other direct (non-tsunami) evidences of the source of the tsunami wave.

Propagation database  A basin-wide database of precomputed water elevations and flow velocities at uniformly spaced grid points throughout the world

oceans. Values are computed from tsunamis generated by earthquakes with a

fault rupture at any one of discrete 100 × 50 km unit sources along worldwide

subduction zones.

Runup  Vertical difference between the elevation of tsunami inundation and

the sea level at the time of a tsunami. Runup is the elevation of the highest 

point of land inundated by a tsunami as measured relative to a stated datum,

such as mean sea level.

Short-term Inundation Forecasting for Tsunamis (SIFT) A tsunami 

forecast system that integrates tsunami observations in deep ocean with numerical models to provide an estimate of tsunami wave arrival and amplitude

at specific coastal locations while a tsunami propagates across an ocean basin.

Subduction zone  A submarine region of the earth’s crust at which two or

more tectonic plates converge to cause one plate to sink under another, overriding plate. Subduction zones are regions of high seismic activity.

Synthetic event  Hypothetical events based on computer simulations or

theory of possible or even likely future scenarios.

Tele-tsunami or distant tsunami or far-field tsunami Most commonly, a 

tsunami originating from a source greater than 1000 km away from a particular location. In some contexts, a tele-tsunami is one that propagates through

deep ocean before reaching a particular location without regard to distance

separation.

Tidal wave  Term frequently used incorrectly as a synonym for tsunami. A

tsunami is unrelated to the predictable periodic rise and fall of sea level due to

the gravitational attractions of the moon and sun; see Tide, below.

Tide  The predictable rise and fall of a body of water (ocean, sea, bay, etc.) due

to the gravitational attractions of the moon and sun.

Tide gauge  An instrument for measuring the rise and fall of a column of water over time at a particular location.
PMEL Tsunami Forecast Series: Vol. 6—Point Reyes, California 163 

Travel time  The time it takes for a tsunami to travel from the generating

source to a particular location.

Tsunameter An oceanographic instrument used to detect and measure tsunamis in the deep ocean. Tsunami measurements are typically transmitted 

acoustically to a surface buoy that in turn relays them in real time to ground

stations via satellite.

Tsunami  A Japanese term that literally translates to “harbor wave.” Tsunamis are a series of long-period shallow water waves that are generated by

the sudden displacement of water due to subsea disturbances such as earthquakes, submarine landslides, or volcanic eruptions. Less commonly, meteoric

impact to the ocean or meteorological forcing can generate a tsunami.

Tsunami hazard assessment A systematic investigation of seismically active regions of the world oceans to determine their potential tsunami impact

at a particular location. Numerical models are typically used to characterize

tsunami generation, propagation, and inundation, and to quantify the risk

posed to a particular community from tsunamis generated in each source region investigated.

Tsunami propagation  The directional movement of a tsunami wave outward

from the source of generation. The speed at which a tsunami propagates depends on the depth of the water column in which the wave is traveling. Tsunamis travel at a speed of 700 km/hr (450 mi/hr) over the average depth of 4000

m in the open deep Pacific Ocean.

Tsunami magnitude  A number that characterizes the strength of a tsunami

based on the tsunami wave amplitudes. Several different tsunami magnitude

determination methods have been proposed.

Tsunami source  Location of tsunami origin, most typically an underwater

earthquake epicenter. Tsunamis are also generated by submarine landslides,

underwater volcanic eruptions, or, less commonly, by meteoric impact of the

ocean. 

Wall-clock time  The time that passes on a common clock or watch between

the start and end of a model run, as distinguished from the time needed by a

CPU or computer processor to complete the run, typically less than wall-clock

time.

Wave amplitude  The maximum vertical rise or drop of a column of water

as measured from wave crest (peak) or trough to a defined mean water level

state.

Wave crest or peak  The highest part of a wave or maximum rise above a

defined mean water level state, such as mean lower low water.

Wave height  The vertical difference between the highest part of a specific

wave (crest) and its corresponding lowest point (trough).
164 Spillane.

Wavelength  The horizontal distance between two successive wave crests or

troughs.

Wave period  The length of time between the passage of two successive wave

crests or troughs as measured at a fixed location.

Wave trough  The lowest part of a wave or the maximum drop below a defined mean water level state, such as mean lower low water.
 	
 
	  
	


 

 	
 



 
 

  

 

  

 	
 

 	 

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Adak

Craig

Shemya

Eureka

Cordova

Chignik

La Push

Nikolski

Florence

Elfin Cove

Arena Cove

Sand Point

Point Reyes

Port Orford

Santa Monica

Westport

Midway Island

Santa Barbara

Port Alexander

Monterey

Homer

Sitka Kodiak

Yakutat

Seaside

Newport

King Cove

San Diego

Unalaska

Port San Luis

Crescent City

Seward

Neah Bay

Garibaldi

Los Angeles

Toke Point

Port Angeles

San Francisco

120°W

120°W

130°W

130°W

140°W

140°W

150°W

150°W

160°W

160°W

170°W

170°W

180°

180°

170°E

170°E

60°N 60°N

50°N 50°N

40°N 40°N

30°N 30°N

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Haleiwa

Kahului

Kawaihae

Honolulu

Nawiliwili

Pearl Harbor

Kailua

Lahaina

Keauhou

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Wake Island

West Coast and Pacific

Tsunami Forecast Model Sites

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Myrtle Beach

Daytona Beach

Cape Hatteras

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Savannah

Portland

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Palm Beach

Ocean City

Morehead City

Atlantic City

Virginia Beach

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80°W

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San Juan

Mayaguez

Ponce

Arecibo Charlotte Amalie

East Coast and Caribbean

Tsunami Forecast Model Sites

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Hawaii American Samoa

U.S. Territories

Kihei.

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