Identification_Information: Citation: Citation_Information: Originator: Suleimani, E.N. Originator: Salisbury, J.B. Originator: Nicolsky, D.J. Originator: Koehler, R.D. Publication_Date: 2019 Title: Regional tsunami hazard assessment for the communities of Port Alexander, Craig, and Ketchikan, Southeast Alaska Geospatial_Data_Presentation_Form: report and digital data Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2019-7 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 23 p., 5 sheets Online_Linkage: http://doi.org/10.14509/30196 Description: Abstract: We assess potential tsunami hazards for coastal communities in Southeast Alaska: Port Alexander, Craig, Saxon, Mountain Point, and Ketchikan. The primary tsunami hazard for these communities is considered to be far-field, with the major threat originating from tsunamigenic earthquakes along the Alaska-Aleutian subduction zone across the Gulf of Alaska. We numerically model tsunami waves generated by four different megathrust earthquakes and develop approximate tsunami hazard maps for the three communities. The hypothetical tsunami scenarios that we examined include variations of an extended 1964 rupture, megathrust earthquakes in the Prince William Sound and the Alaska Peninsula regions, and a Cascadia megathrust earthquake. The maximum runup heights are 4 m (13.1 ft) in Port Alexander, 3.2 m (10.5 ft) in Craig, and 1 m (3.3 ft) in Ketchikan. 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/10.14509/30196. Purpose: 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. Supplemental_Information: >hazard-boundary: Shapefile 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. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2015 Ending_Date: 2019 Currentness_Reference: publication date Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -134.655202 East_Bounding_Coordinate: -131.466178 North_Bounding_Coordinate: 56.254986 South_Bounding_Coordinate: 55.292587 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Active Fault Theme_Keyword: Bathymetry Theme_Keyword: Coastal Theme_Keyword: Coastal and River Theme_Keyword: Earthquake Theme_Keyword: Emergency Preparedness Theme_Keyword: Engineering Theme_Keyword: Engineering Geology Theme_Keyword: Fault Displacement Theme_Keyword: Faulting Theme_Keyword: Faults Theme_Keyword: Flood Theme_Keyword: Geologic Theme_Keyword: Geologic Hazards Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Geotechnical Theme_Keyword: Hazards Theme_Keyword: Inundation Theme_Keyword: Marine Geology Theme_Keyword: Modeling Theme_Keyword: Neotectonics Theme_Keyword: Seismic Hazards Theme_Keyword: Surface Theme_Keyword: Tectonics Theme_Keyword: Tides Theme_Keyword: Tsunami Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Bald Headed Cove Place_Keyword: Behm Canal Place_Keyword: Bucareli Bay Place_Keyword: Chatham Strait Place_Keyword: Chichagof Mining District Place_Keyword: Clam Cove Place_Keyword: Clarence Strait Place_Keyword: Crab Bay Place_Keyword: Craig Place_Keyword: Craig Island Place_Keyword: East Island Place_Keyword: George Inlet Place_Keyword: Herring Bay Place_Keyword: Herring Cove Place_Keyword: Ketchikan Place_Keyword: Knudson Cove Place_Keyword: Mountain Point Place_Keyword: Mud Bay Place_Keyword: Pacific Ocean Place_Keyword: Pennock Island Place_Keyword: Port Alexander Place_Keyword: Port Higgins Place_Keyword: Radenbough Cove Place_Keyword: Refuge Cove Place_Keyword: Refuge Cove State Recreation Site Place_Keyword: Saxman Place_Keyword: Shelter Cove Place_Keyword: Ship Cove Place_Keyword: Southeast Alaska Place_Keyword: Tongass Narrows Place_Keyword: Totem Bight State Historical Park Place_Keyword: Vallenar Bay Place_Keyword: Ward Cove Place_Keyword: Whisky Cove Temporal: Temporal_Keyword_Thesaurus: 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 Temporal_Keyword: Holocene 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Data_Set_Credit: This project, which is part of the National Tsunami Hazard Mitigation Program (NTHMP), 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). Cross_Reference: Citation_Information: Originator: Nicolsky, D.J. Originator: Suleimani, E.N. Originator: Koehler, R.D. Originator: Salisbury, J.B. Publication_Date: 2017 Title: Tsunami inundation maps for Juneau, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2017-9 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 66 p., 5 sheets Online_Linkage: http://doi.org/10.14509/29741 Cross_Reference: Citation_Information: Originator: Nicolsky, D.J. Originator: Suleimani, E.N. Originator: Salisbury, J.B. Publication_Date: 2018 Title: Tsunami inundation maps for Skagway and Haines, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2018-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 69 p., 3 sheets Online_Linkage: http://doi.org/10.14509/30029 Cross_Reference: Citation_Information: Originator: Suleimani, E.N. Originator: Nicolsky, D.J. Originator: Koehler, R.D. Publication_Date: 2013 Title: Tsunami inundation maps of Sitka, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2013-3 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 76 p., 1 sheet, scale 1:12,500 Online_Linkage: http://doi.org/10.14509/26671 Cross_Reference: Citation_Information: Originator: Suleimani, E.N. Originator: Nicolsky, D.J. Originator: Koehler, R.D. Publication_Date: 2015 Title: Tsunami inundation maps of Elfin Cove, Gustavus, and Hoonah, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2015-1 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 79 p., 3 sheets Online_Linkage: http://doi.org/10.14509/29404 Cross_Reference: Citation_Information: Originator: Suleimani, E.N. Originator: Nicolsky, D.J. Originator: Koehler, R.D. Publication_Date: 2016 Title: Tsunami inundation maps for Yakutat, Alaska Series_Information: Series_Name: Report of Investigation Issue_Identification: RI 2016-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 47 p., 1 sheet, scale 1:10,000 Online_Linkage: http://doi.org/10.14509/29577 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: 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. Logical_Consistency_Report: Not applicable Completeness_Report: 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. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: 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. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_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. 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. Lineage: Process_Step: Process_Description: 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. Process_Date: 2011 Process_Step: Process_Description: 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 Port Alexander, Craig, Saxon, Mountain Point, and Ketchikan. 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. Process_Date: 2016 Process_Step: Process_Description: Numerical simulations of hypothetical tsunami scenarios - We assessed hazard related to tectonic tsunamis in Port Alexander, Craig, Saxon, Mountain Point, and Ketchikan 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. Process_Date: 2016 Process_Step: Process_Description: 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. Process_Date: 2016 Process_Step: Process_Description: 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. Process_Date: 2016 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: vector Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: .000001 Longitude_Resolution: .000001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: World Geodetic System of 1984 Ellipsoid_Name: WGS 84 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257223563000025 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Mean Higher High Water Depth_Resolution: 1 Depth_Distance_Units: meter Depth_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: hazard-boundary Entity_Type_Label: ri2019-7-hazard-boundary-craig.shp, ri2019-7-hazard-boundary-ketchikan.shp, ri2019-7-hazard-boundary-port-alexander.shp Entity_Type_Definition: Shapefile 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 Entity_Type_Definition_Source: Alaska Earthquake Center, Geophysical Institute, University of Alaska, this report Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Resource_Description: RI 2019-7 Distribution_Liability: 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. Standard_Order_Process: Non-digital_Form: 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. 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Fees: Contact DGGS for current pricing Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Shapefiles Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://doi.org/10.14509/30196 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20191121 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Person: Simone Montayne Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: 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. Metadata_Extensions: Online_Linkage: http://www.dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions