This dataset was developed as a predictive model for better understanding the likely location of underwater archaeological sites by identifying potential relict submerged landforms, areas most likely to have survived marine transgressive processes associated with sea level rise since the last glacial maximum (LGM).

The model is based on NOAA's National Geophysical Data Center's (NGDC) high-resolution digital elevation models (DEMs) created for select U.S. coastal regions. (These integrated bathymetric-topographic DEMs are used to support tsunami forecasting and warning efforts at the NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL).


Bathymetric, topographic, and shoreline data used in DEM compilation were 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).

This dataset was developed as a predictive model for identifying areas that may contain potential archaeological sites along the Washington, Oregon, and California coastlines, the model does not include any information on the location of known underwater archaeological sites. Rather, these data model areas where relict submerged landforms may be present, features that are associated with a higher potential for the presence of archaeological sites and therefore should undergo additional investigation.