border: Outline of the study area. maximum-inundation-line: Shapefiles which display the estimated, "maximum credible scenario" inundation extent for the communities of Cordova and Tatitlek. These lines are based on model simulation of all credible source scenarios and historical observations. The "maximum credible scenario" inundation lines are intended to be used as a basis for local tsunami hazard planning and development of evacuation maps. max-flow-depth: Raster image depicting maximum composite flow depths over dry land. Pixel values provide the modeled depth (in meters) of maximum inundation. For each grid point, the pixel value provides the modeled depth of water (in meters) over previously dry land, representing the maximum depth value of all calculated tsunami scenarios. time-series-points: To help emergency management personnel assess tsunami hazards in Cordova and Tatitlek, we supplement the inundation maps with the time series plots of the modeled water level and velocity dynamics at some on-land and some offshore locations in the communities. The plots are provided in the appendices of the report. These shapefiles provide the location of each time series point. tectonic-scenario-01: Scenario 1: Mw9.2 earthquake in the Gulf of Alaska region, repeat of the 1964 event, JDM. tectonic-scenario-02: Scenario 2: Mw9.2 earthquake in the Gulf of Alaska region, repeat of the 1964 event, SDM. tectonic-scenario-03: Scenario 3: Mw9.3 multi-segment earthquake based on the JDM. tectonic-scenario-04: Scenario 4: Mw9.3 multi-segment earthquake based on the SDM. tectonic-scenario-05: Scenario 5: Mw8.7 earthquake of the Yakutat-Yakataga segment. tectonic-scenario-06: Scenario 6: Mw9.0-9.1 earthquake in the Cascadia subduction zone. tectonic-scenario-07: Scenario 7: Mw8.8 earthquake in the Gulf of Alaska region, based on case A of the slip distribution: 4-18 km (2.5-11.2 mi) depth, uniform slip along strike. tectonic-scenario-08: Scenario 8: Mw8.8 earthquake in the Gulf of Alaska region, based on case C of the slip distribution: 12-30 km (7.5-18.6 mi) depth, uniform slip along strike. tectonic-scenario-09: Scenario 9: Mw8.8 earthquake in the Gulf of Alaska region, based on case D of the slip distribution: 4-18 km (2.5-11.2 mi) depth, variable slip along strike. tectonic-scenario-10: Scenario 10: Mw8.8 earthquake in the Gulf of Alaska region, based on case F of the slip distribution: 12-30 km (7.5-18.6 mi) depth, variable slip along strike. tectonic-scenario-11: Scenario 11: Mw9.0 earthquake in the Gulf of Alaska region: 4-18 km (2.5-11.2 mi) depth, uniform slip along strike. tectonic-scenario-12: Scenario 12: Mw9.0 earthquake in the Gulf of Alaska region: 4-18 km (2.5-11.2 mi) depth, variable slip along strike. tectonic-scenario-13: Scenario 13 Mw8.8 earthquake in the Gulf of Alaska region: 12-28 km (7.5-17.4 mi) to 17-30 km (10.6-18.6 mi) depth, uniform slip along strike.
Nicolsky, D.J., Suleimani, E.N., and Koehler, R.D., 2014, Tsunami inundation maps of Cordova and Tatitlek, Alaska: Report of Investigation RI 2014-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in decimal degrees.
The horizontal datum used is World Geodetic System of 1984.
The ellipsoid used is WGS 84.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257223563.
Cordova - Appendix A1, Tatitlek - Appendix B1
Cordova - Appendix A2, Tatitlek - Appendix B2
This project was supported by the National Oceanic and Atmospheric Administration (NOAA) under Reimbursable Service Agreement ADN 0931000 with the State of Alaska's Division of Homeland Security and Emergency Management (a division of the Department of Military and Veterans Affairs). Some of the research in this publication is sponsored by the Cooperative Institute for Alaska Research with funds from NOAA under cooperative agreement NA08OAR4320751 with the University of Alaska Fairbanks. 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 Ronni Grapenthin and William Witte for their help with the RTK GPS survey in Cordova and Tatitlek. We also express our gratitude to Julie Elliot for her help in assessing potential earthquakes in the Yakutat block, and for sharing her data with us. Lee Liberty and Shaun Finn provided information on normal faults in Prince William Sound. Natalia Ruppert and Rod Combellick provided valuable contributions to discussions on crustal and subduction-type tsunamigenic earthquakes, and Ian Dickson proofread the manuscript. Insightful reviews by Liujuan (Rachel) Tang and Breanyn MacInnes helped improve this report.
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The purpose of this study is to evaluate potential tsunami hazards for the Prince William Sound communities of Cordova and Tatitlek. We numerically model the extent of inundation from tsunami waves generated by earthquake sources and consider the results in light of historical observations. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake as well as tsunami waves generated by the following hypothetical scenarios: An extended 1964 rupture, a Cascadia megathrust earthquake, various earthquakes in Prince William Sound, and a Tohoku-type earthquake in the Gulf of Alaska region. Results of our numerical modeling, combined with historical observations, are designed to provide guidance to local emergency management agencies in tsunami hazard assessment, evacuation planning, and public education to mitigate damage from future tsunami hazards.
Nicolsky, D.J., Suleimani, E.N., Combellick, R.A., and Hansen, R.A., 2011, Tsunami inundation maps of Whittier and western Passage Canal, Alaska: Report of Investigation RI 2011-7, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Nicolsky, D.J., Suleimani, E.N., Haeussler, P.J., Ryan, H.F., Koehler, R.D., Combellick, R.A., and Hansen, R.A., 2013, Tsunami inundation maps of Port Valdez, Alaska: Report of Investigation RI 2013-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Combellick, R.A., Marriott, D., Hansen, R.A., Venturato, A.J., and Newman, J.C., 2005, Tsunami hazard maps of the Homer and Seldovia areas, Alaska: Report of Investigation RI 2005-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Hansen, R.A., Combellick, R.A., and Carver, G.A., 2002, Tsunami hazard maps of the Kodiak area, Alaska: Report of Investigation RI 2002-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Nicolsky, D.J., West, D.A., Combellick, R.A., and Hansen, R.A., 2010, Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska: Report of Investigation RI 2010-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Nicolsky, D.J., and Koehler, R.D., 2013, Tsunami inundation maps of Sitka, Alaska: Report of Investigation RI 2013-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
The presented maps have been completed using the best information available and are believed to be accurate; however, their preparation required many assumptions. We have considered several tsunami scenarios and have provided an estimate of maximum credible tsunami inundation. Actual conditions during a tsunami event may vary from those considered, so the accuracy cannot be guaranteed. Landslide tsunami sources are not included in the current study due to unknown potential impact of such events on the study area. The limits of inundation shown should only be used as a guideline for emergency planning and response action. Actual areas inundated will depend on specifics of earth deformations, on-land construction, and tide level, and may differ from areas shown on the map. The information on this map 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. Users should review the accompanying report, particularly the Sources of Errors and Uncertainties section, for a detailed discussion of limitations of the methods used to generate the various inundation models. This report has received technical reviews by several scientists familiar with the subject matter. We incorporated the reviewer's suggestions into the final draft.
The extent of tsunami inundation was calculated through numerical modeling of water waves over bathymetry and topography. To efficiently compute a detailed map of potential tsunami inundation, we employed a series of nested computational grids. A nested grid allows for higher resolution in areas where it is needed, without expending computer resources in areas where it is not. The computational grid was based on digital elevation models (DEMs) obtained from various U.S. federal and academic agencies. The highest level of horizontal resolution of the grid used for inundation modeling is about 15 m (49 ft). This scale is mostly limited by the computational resources necessary to compute the tsunami inundation at the higher resolution. The 15 m (49 ft) resolution is high enough to describe major relief features, but small topographic features, buildings, and other facilities cannot be accurately resolved by the existing model. For additional information please reference the Grid Development and Data Sources section of the associated report.
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. Prior to scenario modeling, bathymetric data were shifted to use Mean Higher High Water (MHHW) as the vertical datum. There is a reason to believe that the high-resolution DEM might have some discrepancies at the following two locations. The first location is at the intersection of Water Street and Railroad Avenue (marked with orange crossed circles in figure 20), while the second location is between the Coast Guard Lane and Industry Road (marked with blue crossed circles). Both locations are adjacent to the steep slopes, and hence while developing the DEM for Cordova, the slope terrain might have crept into low-lying regions. Unfortunately, we do not have GPS measurements at either location. Therefore, we adjust the maximum composite inundation extent and assume that both locations might be flooded as nearby areas. 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 Grid Development and Data Sources section of the associated manuscript.
Model validation for this report included modeling of the 1964 tsunami and comparison of the modeled results to observations that were recorded in the historic record. Due to various factors described within accompanying manuscript we were unable to fully account for discrepancies between modeled results and observed water dynamics. We determined that future work is necessary to fully analyze the discrepancy. The dataset contains calculated tsunami inundation limits for tectonic source scenarios. However, tsunamis caused by underwater slope failures are also a significant hazard in the bays of coastal Alaska. Southcentral Alaska has a long record of tsunami waves generated by submarine and subaerial landslides, avalanches, and rock falls. While we acknowledge that coastal communities in Alaska are considered at risk from locally generated waves because of their proximity to landslide-prone areas in a seismically active zone, we did not quantify this category of tsunami hazard in the current report due to poor constraints on the parameters required for to build an appropriate model.
Model validation for this report included modeling of the 1964 tsunami and comparison of the modeled results to observations that were recorded in the historic record.
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- 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).
- Use_Constraints:
- 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.
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| Data format: | Shapefiles, Image files |
|---|---|
| Network links: |
<http://dx.doi.org/10.14509/27241> |
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