HR: 16:05h
AN: S44A-01 [Abstracts]
TI: PERFORMANCE OF ROBUST SOURCE ESTIMATORS FOR LAST YEAR's LARGE EARTHQUAKES
AU: * OKAL, E A
EM: emile@earth.northwestern.edu
AF: Northwestern, University, Evanston, IL 60208, United States
AB:
We report on the performance of real-time estimators
of source characteristics for seven [+] large earthquakes
in the window November 2006 - September [December ?]
2007. The estimators include the improved mantle
magnitude algorithm, the estimation of source moment
using the body-wave algorithms Mwp in both the time and
frequency domains, the slowness parameter THETA introduced
by Newman and Okal [1998], and the high-frequency
P-wave duration estimator Tau-1/3 [Reymond et al., 2006].
The earthquakes considered are the two events in the Kuriles (06319
and 07013), in Taiwan (06360), in the Moluccas (07021), in the Solomons
(07091), Peru (07227) and Santa Cruz (07245). Among them,
the Solomons and Peru events scale predictably, whereas the
Santa Cruz event features a trend towards slowness, reminiscent
of the 1980 source in the same region, and the 2006 Kuril
event has a late source.
By contrast, both the normal faulting 2007
Kuril source, the Moluccas and the Taiwan events feature high values of THETA,
the former reminiscent of the outboard 1977 Sumbawa earthquake,
and characteristic of intraplate earthquakes.
These new data points generally uphold the deficiency of Mwp
for sources exhibiting slowness or even a trend towards it.
An attempt to process the 2006 Aysen, Chile earthquake yielded
poor results, suggesting that these various algorithms fail
below 10**26 dyn*cm.
DE: 7200 SEISMOLOGY
SC: Seismology [S]
MN: 2007 Fall Meeting