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.
Elevations referenced to the National Geodetic Vertical Datum of 1929 (NGVD29).
Zone A: Areas of 100-year flood; base flood elevations and flood hazard factors not determined.
Zone A0: Areas of 100-year shallow flooding where depths are between one (1) and three (3) feet; average depths of inundation are shown, but no flood hazard factors are determined.
Zone AH: Areas of 100-year shallow flooding where depths are between one (1) and three (3) feet; base flood elevations are shown, but no flood hazard factors are determined.
Zone A1-A30: Areas of 100-year flood; base flood elevations and flood hazard factors determined.
Zone A99: Areas of 100-year flood to be protected by flood protection system under construction; base flood elevations and flood hazard factors not determined.
Zone B: Areas between limits of the 100-year flood and 500-year flood; or certain areas subject to 100-year flooding with average depths less than one (1) foot or where the contributing drainage area is less than one square mile; or areas protected by levees from the base flood. (Medium shading)
Zone C: Areas of minimal flooding. (No shading)
Zone D: Areas of undetermined, but possible, flood hazards.
Zone V: Areas of 100-year coastal flood with velocity (wave action); base flood elevations and flood hazard factors not determined.
Zone V1-V30: Areas of 100-year coastal flood with velocity (wave action); base flood elevations and flood hazard factors determined.
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.