Orange triangles are location of continental database entries.  Blue dots are location of oceanic datapoints.

In 1988, work was started on a global database intended to characterize the Earth’s crust.  Today, this database has over 5000 entries, covering a large portion of the Earth’s surface.  The primary data source is from published literature detailing the results of seismic refraction profiles, although some unpublished results have been used as well, especially in Russia and China.  From these seismic profiles, we extract a 1-D seismic velocity model (Vp and Vs if available) for a specific latitude and longitude.  The 1-D model includes the thickness and seismic velocity for each crustal layer as well as annotations of sedimentary layers, velocity gradients, and the moho depth.  Other crustal parameters are added to each point to create a complete image of the Earth’s crust.  Following is a brief explanation of the other parameters included in the database.

The geologic province and thermo-tectonic age maps were compiled in 1997 to ensure a consistent method of providing values for these two parameters.  (see the maps)  With these new data, we are able to examine the relationship of geologic province and thermo-tectonic age to crustal thickness.  (see the histograms)