HR: 1330h
AN: OS22B-1153    [PDF]
TI: Tsunami Inundation Mapping for Alaska Communities of Homer, Seldovia, and Seward
AU: * Suleimani, E
EM: elena@giseis.alaska.edu
AF: Geophysical Institute, University of Alaska Fairbanks, P.O.BOX 757320, Fairbanks, AK 99775-7320 United States
AU: Marriott, D
EM: duncan@giseis.alaska.edu
AF: Geophysical Institute, University of Alaska Fairbanks, P.O.BOX 757320, Fairbanks, AK 99775-7320 United States
AU: Hansen, R
EM: roger@giseis.alaska.edu
AF: Geophysical Institute, University of Alaska Fairbanks, P.O.BOX 757320, Fairbanks, AK 99775-7320 United States
AU: Combellick, R
EM: rod@dnr.state.ak.us
AF: Alaska Division of Geological and Geophysical Surveys, 794 University Avenue, Suite 200, Fairbanks, AK 99709-3645 United States
AB: The Geophysical Institute of the University of Alaska Fairbanks and the Alaska Division of Geological and Geophysical Surveys continue to participate in the National Tsunami Hazard Mitigation Program by evaluating and mapping potential inundation of coastal communities in Alaska. The two Kachemak Bay communities of Homer and Seldovia were selected in coordination with the Alaska Division of Emergency Services. We considered two earthquake scenarios as potential sources of tsunami waves that can affect Homer and Seldovia. For both communities, we calculated the extent of maximum inundation for the two scenarios, depths of inundation on dry land, and the maximum velocity current distribution in the inundation zones. The work is under way for Seward, the next community on the list. One of the most significant sources of errors in tsunami inundation mapping is inaccuracy of topographic and bathymetric data used in the model. Many of the Alaskan communities of interest have topographic data of limited quality, and new data must be developed in order to produce accurate inundation maps. The Alaska Tsunami Modeling Team cooperated with the local USGS glaciology office to perform photogrammetry in the Seward area. Using ten air photos and the APEX software, along with several precisely located GPS points, we developed a new georeferenced and highly accurate DEM with a 5-meter grid spacing. A variety of techniques was used to remove the effects of buildings and trees to yield a bald earth model. Finally, we resampled the new DEM to match the finest resolution grid, and combined it with all other data, using the most recent and accurate data in each region. The new dataset has contours that deviate by more then 100 meters in some places from the contours in the previous dataset, showing significant improvement in accuracy for the purpose of tsunami modeling.
DE: 4255 Numerical modeling
DE: 4564 Tsunamis and storm surges
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting