Suleimani, E.N.
Salisbury, J.B.
Nicolsky, D.J.
Koehler, R.D.
2019
Regional tsunami hazard assessment for selected communities on Kodiak Island, Alaska
report and digital data
Report of Investigation
RI 2019-6
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
31 p., 7 sheets
http://doi.org/10.14509/30195
We assess potential tsunami hazard for the following seven coastal communities on Kodiak Island, Alaska: Akhiok, Chiniak, Karluk, Larsen Bay, Old Harbor, Ouzinkie, and Port Lions. The primary tsunami hazard for these communities is considered to be near-field, with a major threat originating from tsunamigenic earthquakes along the Alaska-Aleutian megathrust. We numerically model tsunamis generated by nine different megathrust earthquakes, analyze tsunami wave dynamics, and develop tsunami hazard maps for the seven communities. The hypothetical tsunami scenarios examined simulate Mw 9.0 megathrust earthquakes with a slip distribution in the 5-54 km (3-34 mi) depth range along the Alaska-Aleutian megathrust. The maximum runup heights are 14 m (46 ft) in Akhiok, 31 m (102 ft) in Chiniak, 11 m (36 ft) in Karluk, 18 m (59 ft) in Larsen Bay, 27 m (89 ft) in Old Harbor, 26 m (85 ft) in Ouzinkie, and 34 m (112 ft) in Port Lions. Results presented here are intended to provide guidance to local emergency management agencies in initial tsunami inundation assessment, evacuation planning, and public education for mitigation of future tsunami hazards. The complete report and digital data are available from the DGGS website: http://doi.org/10.14509/30195.
Results presented here are intended to provide guidance to local emergency management agencies in tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.
>hazard-boundary: Shapefiles depicting maximum assumed runup heights with an included safety factor. These lines are intended to be utilized as a basis for local tsunami hazard planning and the development of evacuation maps.
>post-earthquake-shoreline: Shapefiles depicting post-earthquake modeled MHHW shoreline after coseismic ground changes due to earthquakes.
2015
2019
publication date
None planned
-154.466703
-152.157236
57.947110
56.929366
ISO 19115 Topic Category
geoscientificInformation
Alaska Division of Geological & Geophysical Surveys
Active Fault
Bathymetry
Coastal
Coastal and River
Earthquake
Earthquake Related Slope Failure
Emergency Preparedness
Engineering
Engineering Geology
Environmental
Fault Displacement
Faulting
Faults
Flood
Geologic
Geologic Hazards
Geological Process
Geology
Geotechnical
Hazards
Inundation
Land Subsidence
Marine Geology
Modeling
Neotectonics
Seismic Hazards
Subsidence
Surface
Tectonics
Topography
Tsunami
Alaska Division of Geological & Geophysical Surveys
Akhiok
Alitak Bay
Brookers Lagoon
Chiniak
Chiniak Bay
Chiniak Lake
Chiniak Point
Chiniak River
Gulf of Alaska
Isthmus Point
Karluk
Karluk River
Kodiak Island
Kodiak Mining District
Larsen Bay
Old Harbor
Ouzinkie
Pacific Ocean
Port Lions
Sawmill Lake
Shelikof Strait
Sitkalidak Strait
Walker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of America
Holocene
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
This dataset includes results of numerical modeling of earthquake-generated tsunami waves for a specific community. Modeling was completed using the best information and tsunami modeling software available at the time of analysis. They are numerical solutions and, while they are believed to be accurate, their ultimate accuracy during an actual tsunami will depend on the specifics of earth deformations, on-land construction, tide level, and other parameters at the time of the tsunami. Actual areas of inundation may differ from areas shown in this dataset. Landslide tsunami sources may not be included in the modeling due to unknown potential impact of such events on a given community; please refer to accompanying report for more information on tsunami sources used for this study. The limits of inundation shown should only be used as a general guideline for emergency planning and response action in the event of a major tsunamigenic earthquake. These results are not intended for any other use, including land-use regulation or actuarial purposes. Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
Alaska Division of Geological & Geophysical Surveys
Metadata Manager
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5020
(907)451-5050
dggspubs@alaska.gov
8 am to 4:30 pm, Monday through Friday, except State holidays
This project received support from the National Oceanic and Atmospheric Administration (NOAA) under Reimbursable Services Agreement ADN 952011 with the State of Alaska's Division of Homeland Security & Emergency Management (a division of the Department of Military and Veterans Affairs). Numerical calculations for this work were supported by a grant of High Performance Computing (HPC) resources from the Arctic Region Supercomputing Center (ARSC) at the University of Alaska Fairbanks. We thank Jeff Freymueller for his review that helped to improve the report. We are grateful to Rob Witter and Peter Haeussler for their review of potential tsunami sources.
Nicolsky, D.J.
Suleimani, E.N.
Combellick, R.A.
Hansen, R.A.
2011
Tsunami inundation maps of Whittier and western Passage Canal, Alaska
Report of Investigation
RI 2011-7
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
65 p., 4 sheets
http://doi.org/10.14509/23244
Nicolsky, D.J.
Suleimani, E.N.
Haeussler, P.J.
Ryan, H.F.
Koehler, R.D.
Combellick, R.A.
Hansen, R.A.
2013
Tsunami inundation maps of Port Valdez, Alaska
Report of Investigation
RI 2013-1
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
77 p., 1 sheet, scale 1:12,500
http://doi.org/10.14509/25055
Nicolsky, D.J.
Suleimani, E.N.
Koehler, R.D.
2014
Tsunami inundation maps of Cordova and Tatitlek, Alaska
Report of Investigation
RI 2014-1
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
49 p., 2 sheets
http://doi.org/10.14509/27241
Nicolsky, D.J.
Suleimani, E.N.
Koehler, R.D.
2014
Tsunami inundation maps of the villages of Chenega Bay and northern Sawmill Bay, Alaska
Report of Investigation
RI 2014-3
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
50 p., 7 sheets
http://doi.org/10.14509/29126
Suleimani, E.N.
Nicolsky, D.J.
West, D.A.
Combellick, R.A.
Hansen, R.A.
2010
Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska
Report of Investigation
RI 2010-1
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
47 p., 3 sheets, scale 1:12,500
http://doi.org/10.14509/21001
Suleimani, E.N.
Nicolsky, D.J.
Koehler, R.D.
2017
Updated tsunami inundation maps of the Kodiak area, Alaska
Report of Investigation
RI 2017-8
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
38 p., 10 sheets
http://doi.org/10.14509/29740
Suleimani, E.N.
Nicolsky, D.J.
Salisbury, J.B.
2019
Updated tsunami inundation maps for Homer and Seldovia, Alaska
Report of Investigation
RI 2018-5 v. 2
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
97 p., 11 sheets
http://doi.org/10.14509/30095
Suleimani, E.N.
Salisbury, J.B.
Nicolsky, D.J.
Koehler, R.D.
2019
Regional tsunami hazard assessment for communities on the Kenai Peninsula, Alaska
Report of Investigation
RI 2019-5
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
20 p., 3 sheets
http://doi.org/10.14509/30194
Suleimani, E.N.
Salisbury, J.B.
Nicolsky, D.J.
Koehler, R.D.
2019
Regional tsunami hazard assessment for selected communities on Kodiak Island, Alaska
Report of Investigation
RI 2019-6
Fairbanks, Alaska, United States
Alaska Division of Geological & Geophysical Surveys
31 p., 7 sheets
http://doi.org/10.14509/30195
The hydrodynamic model used to calculate propagation and runup of tectonic tsunamis is a nonlinear, flux-formulated, shallow-water model and has passed the required tests for official use in producing tsunami inundation maps. Most of the uncertainties in the numerical calculations originate from the tsunamigenic earthquake sources used in the models. Uncertainties in the earthquakes, such as the precise location, magnitude, and slip distribution, are the largest sources of error. The direction, amplitude, and arrival times of incoming waves are determined by the initial ocean surface conditions immediately following the earthquake. Therefore, the modeling results are particularly sensitive to the details of the tsunamigenic earthquake rupture, and when the earthquake occurs close to a community, discrepancies can be exacerbated. Furthermore, our assessment of potential earthquake scenarios is by no means exhaustive but represents the best estimate of the locations and sizes of potential tsunami-generating events. It is possible that other unrecognized earthquake scenarios could present hazards to these communities. This DGGS Report of Investigations is a final report of scientific research. Several scientists familiar with the subject matter provided technical reviews. Uncertainties associated with the depiction or interpretation of various features are discussed in the manuscript.
Not applicable
The results of our modeling have been completed using the best information available and are believed to be accurate; however, their preparation required many assumptions and actual conditions during a tsunami event may vary from those considered.
We use a series of nested computational grids to calculate inundation with sufficiently high resolution for each community. The bathymetry and topography in each nested grid are based on digital elevation models (DEMs) developed at the National Centers for Environmental Information (NCEI) of the National Oceanic & Atmospheric Administration (NOAA). The spatial resolution of the fine-resolution grid cells, about 45 x 82 m (147 x 269 ft), satisfies NOAA's minimum recommended requirements for estimation of the tsunami hazard zone (NTHMP, 2010); however, no DEM verification efforts were conducted to reduce uncertainties in the high-resolution (level 3) grid. Therefore, in this report, we do not perform high-resolution runup modeling but provide an estimation of the tsunami hazard zone by extrapolating the maximum composite tsunami wave height on land according to the tsunami scenarios described below. We account for uncertainties inherent to this method by applying a safety factor of 1.3 to the estimated hazard zone.
The vertical accuracy of the inundation modeling is dependent on the accuracy and resolution of the digital elevation models (DEMs) and tidal datum values that were used to compile the computational grid. We provide additional details about DEM and grid development in the accompanying report. Prior to scenario modeling, bathymetric data were shifted to use Mean Higher High Water (MHHW) as the vertical datum. The depths of inundation shown should be used only as a guideline for emergency planning and response action. Actual inundation water depth will depend on specifics of the earth deformations, on-land construction, and tide level, and they may differ from areas shown by this data. The information is intended to permit state and local agencies to plan emergency evacuation and tsunami response actions in the event of a major tsunamigenic earthquake. These results are not intended for land-use regulation or building-code development. For additional information please reference the sources of errors and uncertainties section of the associated manuscript.
Model validation - The numerical model that we used for simulation of tsunami wave propagation and runup was validated through a set of analytical benchmarks and tested against laboratory data. The model solves water equations using a finite-difference method on a staggered grid. See the accompanying report for more detail and additional model information.
2011
Development of nested grids - To support inundation modeling of coastal areas in Alaska, we used a series of nested telescoping grids, or digital elevation models (DEMs), as input layers for tsunami inundation modeling and mapping. These grids of increasing resolution allowed us to propagate waves generated by various sources to Akhiok, Chiniak, Karluk, Larsen Bay, Old Harbor, Ouzinkie, and Port Lions. In order to propagate a wave from its source to various coastal locations, we used embedded grids, placing a large, coarse grid in deep water and coupling it with smaller, finer grids in shallow water areas. The extent of each grid used for our tsunami inundation mapping is listed in the accompanying report.
2015
Numerical simulations of hypothetical tsunami scenarios - We assessed hazards related to tectonic tsunamis in Akhiok, Chiniak, Karluk, Larsen Bay, Old Harbor, Ouzinkie, and Port Lions by performing model simulations for each hypothetical source scenario. For each tsunami scenario, we first calculate the maximum tsunami wave heights in the highest-resolution grid over the course of the entire model run in the following way: at each grid point, the tsunami wave height is computed at every time step during the tsunami propagation time and the maximum value is kept. Then we compute the composite maximum tsunami wave height from all considered scenarios by again choosing the maximum value for each grid point among all scenarios, and plot the results.
2015
Tsunami hazard boundary - After calculating the maximum tsunami height for every grid point in the vicinity of a community, we multiply each highest value grid point by a safety factor of 1.3 (30%) and define it as the maximum runup height. Then we find an elevation contour on the DCRA community map that corresponds to this maximum runup height. This contour is the tsunami hazard boundary.
2015
To create a shapefile for the post-earthquake shoreline resulted from coseismic subsidence - We calculated the amount of coseismic ground subsidence in the community for each scenario considered in the report and select the largest value among all scenarios. Then we subtracted this amount from the community DEM used to model tsunami inundation and calculated the new shoreline position from the boundary between positive (land) and negative (water) values using Matlab.
2015
vector
.000001
.000001
decimal degrees
World Geodetic System of 1984
WGS 84
6378137
298.257223563000025
Mean Higher High Water
1
meter
Attribute values
ri2019-6-hazard-boundary-akhiok.shp, ri2019-6-hazard-boundary-chiniak.shp, ri2019-6-hazard-boundary-karluk.shp, ri2019-6-hazard-boundary-larsen-bay.shp, ri2019-6-hazard-boundary-old-harbor.shp, ri2019-6-hazard-boundary-ouzinkie.shp, ri2019-6-hazard-boundary-port-lions.shp
Shapefiles depicting maximum assumed runup heights with an included safety factor. These lines are intended to be utilized as a basis for local tsunami hazard planning and the development of evacuation maps. File format: shapefile
Alaska Earthquake Center, Geophysical Institute, University of Alaska, this report
hazard-boundary
ri2019-6-post-earthquake-shoreline-akhiok.cpg, ri2019-6-post-earthquake-shoreline-akhiok.shp, ri2019-6-post-earthquake-shoreline-chiniak.shp, ri2019-6-post-earthquake-shoreline-karluk.shp, ri2019-6-post-earthquake-shoreline-larsen-bay.shp, ri2019-6-post-earthquake-shoreline-old-harbor.shp, ri2019-6-post-earthquake-shoreline-ouzinkie.shp, ri2019-6-post-earthquake-shoreline-port-lions.shp
Shapefiles depicting post-earthquake modeled MHHW shoreline after coseismic ground changes due to earthquakes. File format: shapefile
Alaska Earthquake Information Center, Geophysical Institute, University of Alaska, this report
post-earthquake-shoreline
Alaska Division of Geological & Geophysical Surveys
Metadata Manager
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5020
(907)451-5050
dggspubs@alaska.gov
8 am to 4:30 pm, Monday through Friday, except State holidays
RI 2019-6
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
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Shapefiles
http://doi.org/10.14509/30195
Free download
20191125
Alaska Division of Geological & Geophysical Surveys
Simone Montayne
Metadata Manager
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5020
(907)451-5050
dggspubs@alaska.gov
8 am to 4:30 pm, Monday through Friday, except State holidays
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.
http://www.dggs.alaska.gov/metadata/dggs.ext
dggs metadata extensions