Tsunami inundation maps of Whittier and western Passage Canal, Alaska

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What does this data set describe?

Title:
Tsunami inundation maps of Whittier and western Passage Canal, Alaska
Abstract:
The purpose of this study is to evaluate potential tsunami hazards for the community of Whittier and western Passage Canal area. We numerically model the extent of inundation due to tsunami waves generated from earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake, as well as tsunami waves generated by a hypothetically extended 1964 rupture, a hypothetical Cascadia megathrust earthquake, hypothetical earthquakes in Prince William Sound, and Kodiak asperities of the 1964 rupture. Local underwater landslide and rockslide events in Passage Canal are also considered as credible tsunamigenic scenarios. Results of numerical modeling combined with historical observations in the region are intended to provide guidance to local emergency management agencies in tsunami hazard assessment, evacuation planning, and public education for reducing future tsunami damage.
Supplemental_Information:
The DGGS metadata standard extends the FGDC standard to include elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships and correspond to subdirectories within the data distribution package. The metadata layer provides the metadata or other documentation files. Attribute information for each data layer is described in this metadata file under the "Entity_and_Attribute_Information" section. Data layer contents:
mhhw-shoreline:    The modern shoreline (mean higher high water - MHHW) of the study area at the time of publication; see Grid Development and Data Sources section of this report to learn more about how this file was created.
hypothetical-composite-line:    Estimated, "maximum credible scenario" inundation line that encompasses the maximum extent of flooding based on model simulation of all credible source scenarios and historical observations. The "maximum credible scenario" inundation line becomes a basis for local tsunami hazard planning and development of evacuation maps.
hypothetical-composite-line-half-m-depth:    Extent of potential 0.5 meter water flow depth
hypothetical-composite-line-two-m-depth:    Extent of potential 2 meter water flow depth
tectonic-scenario-01:    Scenario 1. Repeat of the 1964 event: Source function based on coseismic deformation model by Johnson and others (1996)
tectonic-scenario-02:    Scenario 2. Repeat of the 1964 event: Source function based on coseismic deformation model by Suito and Freymueller (2009)
tectonic-scenario-05:    Scenario 5. Rupture of the Cascadia zone, including portions of the margin along the British Columbia and northern California shores
landslide-scenario-10:    Scenario 10. Repeat of the 1964 event: Major underwater slide complexes of the 1964 earthquake - Harbor, Airport, and Glacier (HAG) landslides
landslide-scenario-11:    Scenario 11. Hypothetical event: Major underwater slide complex offshore of the northern shore of Passage Canal
landslide-scenario-12:    Scenario 12. Hypothetical event: Major underwater slide complex offshore of the Billings Creek delta
landslide-scenario-13:    Scenario 13. Hypothetical event: Simultaneous failure of underwater slide complexes described by scenarios 10-12
  1. How should this data set be cited?

    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:

    Other_Citation_Details: 65 p.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -148.724616
    East_Bounding_Coordinate: -148.657100
    North_Bounding_Coordinate: 60.794707
    South_Bounding_Coordinate: 60.769182

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 2011
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: report, digital-data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a vector data set.

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 6
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -147
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000.000000
      False_Northing: 0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000001
      Ordinates (y-coordinates) are specified to the nearest 0.000001
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is North American Datum of 1983.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    ri2011-7-mhhw-shoreline
    The modern shoreline (mean higher high water - MHHW) of the study area at the time of publication; see Grid Development and Data Sources section of this report to learn more about how this file was created. File format: shapefile (Source: This report)

    ri2011-7-hypothetical-composite-line
    Estimated, "maximum credible scenario" inundation line that encompasses the maximum extent of flooding based on model simulation of all credible source scenarios and historical observations. The "maximum credible scenario" inundation line becomes a basis for local tsunami hazard planning and development of evacuation maps. File format: shapefile (Source: This report)

    ri2011-7-hypothetical-composite-line-half-m-depth
    Extent of potential 0.5 meter water flow depth File format: shapefile (Source: This report)

    ri2011-7-hypothetical-composite-line-two-m-depth
    Extent of potential 2 meter water flow depth File format: shapefile (Source: This report)

    ri2011-7-tectonic-scenario-01
    Scenario 1. Repeat of the 1964 event: Source function based on coseismic deformation model by Johnson and others (1996) File format: shapefile (Source: This report)

    ri2011-7-tectonic-scenario-02
    Scenario 2. Repeat of the 1964 event: Source function based on coseismic deformation model by Suito and Freymueller (2009) File format: shapefile (Source: This report)

    ri2011-7-tectonic-scenario-05
    Scenario 5. Rupture of the Cascadia zone, including portions of the margin along the British Columbia and northern California shores File format: shapefile (Source: This report)

    ri2011-7-landslide-scenario-10
    Scenario 10. Repeat of the 1964 event: Major underwater slide complexes of the 1964 earthquake - Harbor, Airport, and Glacier (HAG) landslides File format: shapefile (Source: This report)

    ri2011-7-landslide-scenario-11
    Scenario 11. Hypothetical event: Major underwater slide complex offshore of the northern shore of Passage Canal File format: shapefile (Source: This report)

    ri2011-7-landslide-scenario-12
    Scenario 12. Hypothetical event: Major underwater slide complex offshore of the Billings Creek delta File format: shapefile (Source: This report)

    ri2011-7-landslide-scenario-13
    Scenario 13. Hypothetical event: Simultaneous failure of underwater slide complexes described by scenarios 10-12 File format: shapefile (Source: This report)


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    This project was supported by the National Oceanic and Atmospheric Administration grants 27-014d and 06- 028a through Cooperative Institute for Arctic Research. 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 as part of the U.S. Department of Defense High Performance Computing Modernization Program. Reviews by Dr. Timothy Walsh and Dr. Juan Horrillo improved the report and maps. We thank R. Grapenthin and B. Witte for their help with the RTK GPS survey in Whittier.

  3. To whom should users address questions about the data?

    Alaska Division of Geological & Geophysical Surveys
    GIS Manager
    3354 College Road
    Fairbanks, AK 99709-3707
    USA

    (907)451-5020 (voice)
    dggsgis@alaska.gov

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays


Why was the data set created?

The purpose of this study is to evaluate potential tsunami hazards for the community of Whittier and western Passage Canal area. We numerically model the extent of inundation due to tsunami waves generated from earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake, as well as tsunami waves generated by a hypothetically extended 1964 rupture, a hypothetical Cascadia megathrust earthquake, hypothetical earthquakes in Prince William Sound, and Kodiak asperities of the 1964 rupture. Local underwater landslide and rockslide events in Passage Canal are also considered as credible tsunamigenic scenarios. Results of numerical modeling combined with historical observations in the region are intended to provide guidance to local emergency management agencies in tsunami hazard assessment, evacuation planning, and public education for reducing future tsunami damage.


How was the data set created?

  1. From what previous works were the data drawn?

    Caldwell, R.J. and others, 2011 (source 1 of 5)
    Caldwell, R.J., Eakins, B.W., and Lim, E., 2011, Digital elevation models of Prince William Sound, Alaska-Procedures, data sources and analysis: NOAA Technical Memorandum NESDIS NGDC-40, National Geophysical Data Center, Marine Geology and Geophysics Division, United States.

    Type_of_Source_Media: digital data
    Source_Contribution: development of nested grids

    Nicolsky, D.J and others, 2011 (source 2 of 5)
    Nicolsky, D.J, Suleimani, E.N, and Hansen, R.A, 2011, Validation and verification of a numerical model for tsunami propagation and runup: Pure and Applied Geophysics v. 168, Birkhauser Geoscience, Switzerland.

    Type_of_Source_Media: paper
    Source_Contribution: model validation

    Suito, Hisashi and Freymueller, J.T, 2010 (source 3 of 5)
    Suito, Hisashi, and Freymueller, J.T, 2010, A viscoelastic and afterslip postseismic deformation model for the 1964 Alaska earthquake: Journal of Geophysical Research v. 114, no. B11, American Geophysical Union, Washington, DC, United States.

    Type_of_Source_Media: paper
    Source_Contribution: model verification

    Kachadoorian, Reuben, 1965 (source 4 of 5)
    Kachadoorian, Reuben, 1965, Effects of the earthquake of March 27, 1964, at Whittier, Alaska: Professional Paper P 542-B, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: p. B1-B21, 3 sheets, scale 1:4,800
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 4800
    Source_Contribution: model verification

    Johnson, J.M. and others, 1996 (source 5 of 5)
    Johnson, J.M., Satake, Kenji, Holdahl, S.R., and Sauber, Jeanne, 1996, The 1964 Prince William Sound earthquake-Joint inversion of tsunami waveforms and geodetic data: Journal of Geophysical Research v. 101, no. B1, American Geophysical Union, Washington, DC, United States.

    Type_of_Source_Media: paper
    Source_Contribution: model verification

  2. How were the data generated, processed, and modified?

    Date: 2009 (process 1 of 7)
    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. The topographic datasets were augmented with high-accuracy data, that is, a real time kinematic (RTK) GPS survey within the harbor area and along near-shore areas in Whittier. These grids of increasing resolution allowed us to propagate waves generated by both distant and local sources to Passage Canal. 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. See Methodology and data section of this report for more detail and additional data source information.

    Data sources used in this process:

    • Caldwell, R.J. and others, 2011

    Date: 2010 (process 2 of 7)
    Model validation - The numerical model that was 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 nonlinear shallow water equations using a finite-difference method on a staggered grid. See Methodology and data section of this report for more detail and additional model information.

    Data sources used in this process:

    • Nicolsky, D.J and others, 2011

    Date: 2010 (process 3 of 7)
    Model verification - We performed the verification of the numerical model using observations of the 1964 tsunami. We compared results of inundation modeling in Passage Canal and Whittier with observations collected shortly after the event. First, we simulated tsunami waves generated by multiple submarine slope failures using a numerical model of a viscous slide coupled with a numerical model for water waves. Then, we simulated the tectonic tsunami in Passage Canal using an output of a coseismic deformation model of the 1964 earthquake as an initial condition for water waves. The composite inundation zone was compared with the observed extent of inundation in Whittier and at the head of Passage Canal. See Methodology and data and Modeling results sections of this report for more detail and additional model information.

    Data sources used in this process:

    • Suito, Hisashi and Freymueller, J.T, 2010
    • Kachadoorian, Reuben, 1965
    • Johnson, J.M. and others, 1996

    Date: 2010 (process 4 of 7)
    Numerical simulations of hypothetical tsunami scenarios - We assessed hazard related to tectonic and landslide-generated tsunamis in Passage Canal by performing model simulations for each hypothetical earthquake and landslide source scenario. The numerical results for each scenario include extent of inundation, sea level and velocity time series, and tsunami flow depth. See Modeling results section of this report for more detail and additional information.

    Date: 2010 (process 5 of 7)
    Numerical simulations of potential rockfall-generated tsunami - We assessed hazard related to two scenarios of the rockfall-generated tsunamis in Passage Canal by performing model simulations. Numerical results for each scenario include extent of inundation, sea level and velocity time series, and tsunami flow depth. See Appendix A section of the associated report for more detail and additional information.

    Date: 2010 (process 6 of 7)
    Compilation of maximum inundation zone and maximum flow depths - Compilation of maximum inundation zone and maximum flow depths - We calculated maximum composite extent of inundation by combining the maximum calculated inundation extents of all scenarios. The same method was used for calculation of maximum flow depths over dry land. See Modeling results section of the associated manuscript for more detail and additional information.

    Date: 2010 (process 7 of 7)
    Calculation of the potential inundation lines - For each grid cell in the high-resolution DEM of Whittier, we found whether this cell was inundated by waves or stayed dry through out the entire simulation. Then, we defined a function that provides a value that is equal to one at the center of each wet cell and is equal to negative one at the center of each dry cell. Using a linear interpolation algorithm in Matlab, we plotted a zero-value contour that delineates dry and wet cells from each other. The contour line was then directly exported to the ArcGIS in the WGS84 datum. The datum was subsequently changed to the datum of the background image.

  3. What similar or related data should the user be aware of?

    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:

    Other_Citation_Details: 77 p., 1 sheet, scale 1:12,500
    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:

    Other_Citation_Details: 28 p., 2 sheets, scale 1:12,500
    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:

    Other_Citation_Details: 16 p., 4 sheets, scale 1:12,500
    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:

    Other_Citation_Details: 47 p., 3 sheets, scale 1:12,500
    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:

    Other_Citation_Details: 76 p., 1 sheet, scale 1:250,000


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    The extent of inundation caused by hypothetical future tsunami waves was calculated using numerical modeling of tsunami wave propagation and runup. The final, highest resolution grid of the western Passage Canal, where the inundation extent was calculated, has a spacing of approximately 15 meters. Although the location of the inundation line has an accuracy of approximately plus or minus 15 m horizontally relative to the grid spacing, the true location accuracy is unknown, because of the complex modeling process the accuracy depends on many factors. These factors include correctness of the earthquake source model, accuracy of the bathymetric and topographic data, soil compaction in areas of unconsolidated deposits and the adequacy of the numerical model in representing the generation, propagation, and run-up of tsunami waves. 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 limits of inundation shown should only be used as a guideline for emergency planning and response action. 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 event. These files are not intended for land-use regulation, property valuation, or any use other than the stated purpose. 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.

  2. How accurate are the geographic locations?

    The extent of tsunami inundation in Whittier was calculated through numerical modeling of water waves over realistic bathymetry and topography. The input data for the tsunami model includes the combined topographic and bathymetric DEM of 15-m resolution described in NGDC NOAA report "Digital elevation models of Prince William Sound, Alaska-Procedures, Data Sources and Analysis" by Caldwell, R.J., Eakins, B.W., and Lim, E. According to the corresponding metadata file, the accuracy of the high-resolution DEM developed is determined by the topographic datasets with the vertical accuracy of 10-15 m (33-50 ft). Since the DEM can posses large vertical errors near the shoreline, the topographic datasets are augmented with high-accuracy data, that is, a real time kinematic (RTK) GPS survey within the harbor area and along near-shore areas in Whittier. We estimate that the GPS observations have the vertical accuracy of 1 m (3.3 ft) in flat-lying areas where there are no abrupt topographic changes. Finally, we note that the collected GPS measurements are recorded in WGS84 horizontal datum, with the horizontal accuracy of approximately 3-5 m (10-16 ft). For additional information please reference the "Grid development and data sources" section of this report.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    We modeled inundation extents resulting from 14 different scenarios (tsunami, landslide, and rockfall). Each scenario is described in the text report. This digital data distribution package presents shapefiles that outline the extent of the scenarios that produced a "significant" inundation in Whittier. We also include two additional shapefiles that outline where the modeled water depth of the maximum innundation scenario is expected to be 0.5 and 2 meters. The inundation limits and flow depths are results of numerical modeling of tsunami waves with the use of shallow water equations. We conducted all model runs using bathymetric data that correspond to Mean Higher High Water so that the resulting maximum inundation line represents a reasonable worst-case scenario of tsunami occurrence at high tide. The model does not take into account the periodical change of sea level due to tides, but it does include the effect of local uplift or subsidence during the earthquake. The average recurrence intervals for the tectonic source events are poorly known. Scenarios 1 and 2, which are repeats of the magnitude 9.2 great earthquake of 1964, have an estimated median recurrence interval of 589 years, based on paleoseismic data (Carver and Plafker, 2008). The recurrence intervals for tsunamigenic underwater landslides in Passage Canal is unknown. The recurrence interval for the potential rockfall-generated tsunami is also unknown. The data used to calculate the potential extent of tsunami inundation includes: high-resolution topography and bathymetry of Passage Canal, historic records of the 1964 inundation line at Whittier, historic seismicity measurements, pre- and post-1964 bathymetric profiles in the western part of Passage Canal, and related tectonic geometry. The western part of Passage Canal has been studied in great detail and we feel that the density of available information is sufficient to allow for confidence in our interpretations of likely extents of tsunami inundation. The potential rockfall area require additional in-situ measurements to constrain volume, configuration and dynamics of the potential rockfall failure.

  5. How consistent are the relationships among the observations, including topology?

    Results of numerical modeling were verified by simulating historic tsunamis. Inundation lines are visually inspected using GIS software for identification of anomalous elevations or data inconsistencies. See text report for detailed explanation of the tests used to determine the fidelity among the various data sources that were used to generate this dataset.


How can someone get a copy of the data set?

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.

  1. Who distributes the data set? (Distributor 1 of 1)

    Alaska Division of Geological & Geophysical Surveys
    3354 College Road
    Fairbanks, AK 99709-3707
    USA

    (907)451-5020 (voice)
    (907)451-5050 (FAX)
    dggspubs@alaska.gov

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (<http://www.dggs.alaska.gov>) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set?

    RI 2011-7

  3. What legal disclaimers am I supposed to read?

    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.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 06-Dec-2013
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
USA

(907)451-5020 (voice)

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


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