HR: 0800h
AN: S21A-0270 [Abstracts]
TI: Automated Moment Tensor Solution for the Southern California Seismic Network
AU: * Clinton, J F
EM: jclinton@caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
United States
AU: Hauksson, E
EM: hauksson@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
United States
AU: Solanki, K
EM: solanki@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125
United States
AB:
Automatically generated moment tensor solutions have recently been added to the suite of real-time products produced by the
Southern California Seismic Network (SCSN/CISN). The moment magnitude, Mw, and the moment tensor are available within minutes
for all regional earthquakes that trigger the network with Ml>4.0, and in special cases for events between Ml 3.5-4.0. The
method uses the 1-D Time-Domain INVerse Code (TDMT\_INVC) software package developed by Doug Dreger, which is routinely used
in real-time by the UC Berkeley Seismological Laboratory. Green's Functions are determined for various velocity profiles in
Southern California, which are used in the inversion of observed three component broadband waveforms (10s-100s) for a number
of stations.
The duty seismologists will review the automatically generated solution before distribution. A web-interface has been
developed to evaluate the quality of the automatic solution, and determine whether it meets the minimum requirements for an
immediate distribution. Simple modifications to the stations selected for the inversion are possible, and the inversion can
be re-run to optimise the solution. The Mw determined with this method will be the official SCSN/CISN Mw solution for the
event.
Comparisons of the moment tensors determined using this 1-D model are made with 3-D models generated for larger earthquakes
in the Southern California to facilitate calibration of the automated algorithm.
DE: 7294 Instruments and techniques
DE: 7299 General or miscellaneous
DE: 7215 Earthquake parameters
SC: Seismology [S]
MN: 2004 AGU Fall Meeting