SCEC offers two alternative Community Velocity Models of southern California:

CVM-H (after Suess and Shaw., 2003) is a compressional wave velocity (Vp) model based on tens of thousands of direct velocity measured from well logs and seismic reflection data and geostatistical interpolation techniques. Shear wave velocity and density values are defined based on empirical correlations with Vp established using dipole sonic and density log data. CVM 4.0 includes a description of basin shape defined largely by seismic reflection data, and is consistent with the positions and offsets of major faults as represented in the SCEC Community Fault Model (CFM).

CVM-H 4.0 is available at the following site:

• SCEC CVM-H SCEC Community Velocity Model - Harvard

CVM 4.0 (after Magistrale et al., 2000) is a rule-based velocity description, where compressional wave velocity (Vp) is defined as a function of sediment age and depth. Shear wave velocity and density values are defined based on scaling relationships with Vp. CVM 4.0 includes a description of basin shape and several stratigraphic horizons, as well as a geotechnical layer above 300m depth.

CVM 4.0 is available at the following site:

• SCEC CVM-4 SCEC Community Velocity Model - 4

SCEC offers a Community Fault Model that provides 3-D representations of active fault systems deemed capable of generating moderate to large earthquakes. The model is available in two forms:

CFM 3.0 represents faults systems as triangulated surfaces and is available in the following formats:

• CFM 3.0 - SCEC Community Fault Model and access to CFM database

CFM-R 2.5 represents faults with rectilinear segments and is available in the following formats:

• CFM-R 2.5 - SCEC Community Fault Model Rectilinear Grid including traces and corner points.
  

The Southern California Earthquake Center (SCEC) released the SCEC Crustal Motion Map, Version 3.0 by

Z.-K. Shen, D. C. Agnew, R. W. King, D. Dong, T. A. Herring, M. Wang, H. Johnson, G. Anderson, R. Nikolaidis, M. van Domselaar, K. W. Hudnut, and D. D. Jackson

This release contains 833 estimates of current station velocities (relative to North America) at 762 points in Southern California and northern Baja California, together with coseismic offsets for many of these points from the Landers, Northridge, and Hector Mine earthquakes. Downloadable files, and additional information, can be found at

• SCEC CMM Version 3 Web Pages