|Portland, Maine Coastal Digital Elevation Model
||NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital
elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic
DEMs are used to support tsunami forecasting and modeling efforts at the NOAA Center
for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL). The DEMs are
part of the tsunami forecast system SIFT (Short-term Inundation Forecasting for Tsunamis)
currently being developed by PMEL for the NOAA Tsunami Warning Centers, and are used
in the MOST (Method of Splitting Tsunami) model developed by PMEL to simulate tsunami
generation, propagation, and inundation. 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 the vertical tidal datum of Mean High Water (MHW) and horizontal
datum of World Geodetic System 1984 (WGS84). Grid spacings for the DEMs range from
1/3 arc-second (~10 meters) to 3 arc-seconds (~90 meters).