03-29-2014, 11:52 AM
The USGS summary is interesting.
http://earthquake.usgs.gov/earthquakes/e...73#summary
It says "could" be associated with Puente Hills thrust. The Puente Hills thrust is clearly imaged on industry seismic reflection data in the upper few km, as published by Shaw and Shearer (1999). This shallow part of the fault projects in 3D down to the 1987 Whittier earthquake. But, the focal mechanism shows more of a NW dip:
http://earthquake.usgs.gov/earthquakes/e...scientific
and the aftershocks make a clear NE-SW alignment. Perhaps this is a tear fault (lateral ramp). It would be interesting to see these quakes in 3D.
I'll go into Gocad and see what the Southern California Earthquake Center Community Fault Model looks like there, and try and post this.
Chris
http://earthquake.usgs.gov/earthquakes/e...73#summary
It says "could" be associated with Puente Hills thrust. The Puente Hills thrust is clearly imaged on industry seismic reflection data in the upper few km, as published by Shaw and Shearer (1999). This shallow part of the fault projects in 3D down to the 1987 Whittier earthquake. But, the focal mechanism shows more of a NW dip:
http://earthquake.usgs.gov/earthquakes/e...scientific
and the aftershocks make a clear NE-SW alignment. Perhaps this is a tear fault (lateral ramp). It would be interesting to see these quakes in 3D.
I'll go into Gocad and see what the Southern California Earthquake Center Community Fault Model looks like there, and try and post this.
Chris