Federal Emergency Management Agency (FEMA) Federal Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades (Tsunami Pilot Study Working Group, 2006). Therefore, as part of FEMAs Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to provide information from which tsunami mapping guidelines could be developed. This area was chosen because it is typical of coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca. There was also considerable interest shown by state agencies and local stakeholders in mapping the tsunami threat to this area. The study was an interagency effort by scientists from the U.S. Geological Survey, the National Oceanic and Atmospheric Administration, the University of Southern California, and the Middle East Technical University. We present the GIS data from that report in this publication.
These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.
iy01_005 - PTHA probabilities determined by input from all far- and near-field sources
iy01_005aa - probabilities determined using only source 1 of the Alaska-Aleutian segmentation
iy01_005td480 - PTHA wave heights determined using a mean inter-event time of 480 years (mean value from records)
iy01_005td560 - PTHA wave heights determined using a mean inter-event time of 560 years (value from model)
The data are provided as grids in xyz and as Arcinfo ASCIIGRID format files (.asc). Grid cell spacing is 0.000558-degree (~60 meters) with probability values for each of the 21 wave height intervals 0.5 to 10.5 meters at 0.5-meter intervals.
Example of .xyz format:
-123.969688 46.059677 0.038109 -123.969131 46.059677 0.038109 -123.968575 46.059677 0.038109 -123.968010 46.059677 0.038109The .asc file consists of header information containing a set of keywords, followed by cell values in row-major order. The file format is
ncols 133 nrows 183 xllcorner -123.969967 yllcorner 45.957843 cellsize 0.000558 NODATA_value -9999 row 1 row 2 . . . row nFiles included in each set
iy01_005.xyz iy01_005.asc iy02_010.xyz iy02_010.asc iy03_015.xyz iy03_015.asc iy04_020.xyz iy04_020.asc iy05_025.xyz iy05_025.asc iy06_030.xyz iy06_030.asc iy07_035.xyz iy07_035.asc iy08_040.xyz iy08_040.asc iy09_045.xyz iy09_045.asc iy10_050.xyz iy10_050.asc iy11_055.xyz iy11_055.asc iy12_060.xyz iy12_060.asc iy13_065.xyz iy13_065.asc iy14_070.xyz iy14_070.asc iy15_075.xyz iy15_075.asc iy16_080.xyz iy16_080.asc iy17_085.xyz iy17_085.asc iy18_090.xyz iy18_090.asc iy19_095.xyz iy19_095.asc iy20_100.xyz iy20_100.asc iy21_105.xyz iy21_105.asc
Please recognize the U.S. Geological Survey (USGS) as the source of this information.
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.
The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.
This information is not intended for navigational purposes.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.