National Tsunami Hazard Mitigation Program
Digital Elevation Models
(NTHMP DEMs)

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the National Tsunami Hazard Mitigation Program's efforts to improve community preparedness and hazard mitigation. These integrated bathymetric-topographic DEMs are used to support tsunami modeling and coastal inundation mapping.

Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to various vertical and horizontal datums depending on the specific modeling requirements of each State. For specific datum information on each DEM, refer to the appropriate DEM documentation. Cell sizes for the DEMs also vary depending on the specifications required by modelers in each State, but typically range from 1/3 arc-second (~10 meters) to 8 arc-seconds (~240 meters)

How to Cite DEMs:

For each DEM, cite the accompanying DEM Development Report.