This is the metafile provided by Ralph Petter, G&ES 391, Spring 2001 after
he digitized seismic data.  Need from him still:

It was produced by The Global Seismic Hazard Assessment Program.
2) The attribute mapped (index) is peak ground acceleration (m/s2) that a site
can expect during the next 50 years with 10 percent probability.

ABSTRACT: This dataset contains information about the amount of seismic
activity that can be experienced in different areas of the continental United
States. It is used to determine the likelihood of an earthquake. 500 scientists
participated in the making of this map, and it took 7 years to do.  The
original map was released in December 1999 Zones of activity are separated by
colors that represents the average amount of activity in that zone.  Areas of
high activity are coded red and areas of no activity are colored white.
 
PURPOSE: Determine the earthquake hazard in the United States.
 
SPACIAL REFERENCE: The final map is in the Mercator projection and covers the
entire United States.
 
LANGUAGE: Numeric data.
 
PROCESS: The original U.S. map was reduced from a world map.  The data was
sumarized in preparation for digitising. It was then manually digitised.

 
METHOD: The dataset was digitized on screen using Maptitude 4.2.
 
MATERIAL: The original map was produced by the Global Seismic Hazard Program,
and was produced to assist in risk management in various parts of the world.
The map of the United States represents a small portion on the entire project.
 
 