Conor Watkins (cwatkins@usgs.gov), U.S. Geological Survey, Mid-Continent Geographic Science Center, Rolla, Mo.

St. Louis Area Earthquake Hazards Mapping Project is a cooperative effort of the U.S. Geological Survey and other public and private entities.  The project includes collection of geotechnical data from other sources to assist with subsurface characterization in the project area, which encompasses approximately 3,100 square kilometers of Missouri and Illinois within the St. Louis Metro area.  Sources include the U.S. Army Corps of Engineers, the Missouri Department of Transportation, and engineering firms.  Interpretation of these data will aid the prediction of site response at various localities throughout the project area and the production of seismic hazards maps based on scenario earthquakes affecting the region. 

The use of data from other sources provides a tremendous cost savings to the project and allows for a greater density of information in the prediction of seismic hazards.  However, data from various sources arrive in a variety of formats and standards.  Often, data collected for a specific project only cover a limited area.  Good examples are geotechnical borings from the Missouri Department of Transportation and the U.S. Army Corps of Engineers, which tend to be restricted to the locations of highways or flood protection levees, respectively.  Older data often arrive in analog formats lacking a well-defined spatial reference.  Paper maps and photographs must be digitally scanned and georeferenced to existing cospatial imagery and maps.  Geotechnical data contains varying levels of detail which must be accounted for when using them for subsurface characterization.