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.
Suleimani, E.N., Nicolsky, D.J., and Salisbury, J.B., 2020, Regional tsunami hazard assessment for communities of Bristol Bay and the Pribilof Islands, Alaska: Report of Investigation RI 2020-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This is a vector data set.
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest .000001. Longitudes are given to the nearest .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 1/298.257223563000025.
This project received support from the National Oceanic and Atmospheric Administration (NOAA) under grant awards: NA16NWS4670030, NA17NWS4670006, and NA19NWS4670008 with the State of Alaska's Division of Homeland Security & Emergency Management. 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.
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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.
Nicolsky, D.J., Suleimani, E.N., Freymueller, J.T., and Koehler, R.D., 2015, Tsunami inundation maps of Fox Islands communities, including Dutch Harbor and Akutan, Alaska: Report of Investigation RI 2015-5, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Salisbury, J.B., Nicolsky, D.J., and West, M.E., 2019, Tsunami inundation maps for Adak and Atka, Alaska: Report of Investigation RI 2019-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Nicolsky, D.J., Koehler, R.D., Freymueller, J.T., and Macpherson, A.E., 2016, Tsunami inundation maps for King Cove and Cold Bay communities, Alaska: Report of Investigation RI 2016-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Suleimani, E.N., Salisbury, J.B., Nicolsky, D.J., and Koehler, R.D., 2019, Regional tsunami hazard assessment for False Pass and Perryville, Alaska: Report of Investigation RI 2019-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Nicolsky, D.J., Suleimani, E.N., and Koehler, R.D., 2016, Tsunami inundation map for the village of Nikolski, Alaska: Report of Investigation RI 2016-7, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
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.
We model tsunami waves and inundation using a series of nested computational grids. A nested grid allows for higher resolution computations in areas where detail is needed while minimizing computer runtime in areas where such detail is not required. The bathymetric and topographic relief in each nested grid is based on DEMs developed at the NCEI. The extent of each grid used for the Bristol Bay and Pribilof Islands mapping project is shown in figure 3 and listed in table 2. The coarsest grid (level 0), with 2-arc-minute (approximately 2 km) resolution, spans the central and northern Pacific Ocean. The bathymetric data for the 2-arc-minute-resolution grid is extracted from the ETOPO2 dataset. We use two intermediate grids between the coarsest- and highest-resolution grids (table 2). The data sources and methodology used to develop the 24-arc-second DEMs are described in detail by Lim and others (2011). The 8- and 8/3-arc-second DEMs were developed by the NCEI in the scope of NTHMP. The spatial resolution of the fine resolution grid cells, which is ~48 x 82 m (157 x 269 ft), satisfies NOAA's minimum recommended requirements for estimation of the tsunami hazard zone. We stress that this grid spacing is not adequate for the high-resolution modeling of the inundation zone and no DEM verification efforts were conducted to reduce uncertainties in the fine resolution grids for Dillingham, Nelson Lagoon, and Platinum. Therefore, in this report we perform high-resolution runup modeling only for the communities of St. Paul and St. George. For the communities of Dillingham, Nelson Lagoon, and Platinum we provide an estimation of the tsunami hazard zone by extrapolating the maximum composite tsunami wave height onto land according to the tsunami scenarios described below. We account for uncertainties inherent to this method by applying a 30 percent safety factor 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.
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.
Not applicable
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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RI 2020-1
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| Data format: | Shapefiles |
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| Network links: |
<http://doi.org/10.14509/30422> |
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