HR: 1340h
AN: S13B-0196    [Abstracts]
TI: Quantifying Properties Of Triggering (Non-Triggering) Local Mainshock/Aftershock Sequences: Establishing Thresholds That Can Be Applied To Remote Mainshock/Aftershock Triggering Studies
AU: * Kane, D L
EM: dlkane@ucsd.edu
AF: Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, University of California, San Diego, La Jolla, CA 92093
AU: Kilb, D
EM: dkilb@ucsd.edu
AF: Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, University of California, San Diego, La Jolla, CA 92093
AU: Berg, A
EM: aberg@math.ucsd.edu
AF: Mathematics Department, University of California, San Diego, La Jolla, CA 92093
AU: Martynov, V G
EM: vladik@ucsd.edu
AF: Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, University of California, San Diego, La Jolla, CA 92093
AB: Various studies have examined remote earthquake triggering in geothermal areas, but few studies have sought out triggering in non-geothermal areas. We search the 22-year ANZA (southern California) network catalog for evidence of remote triggering. Using three statistical tests (Binomial, Wilcoxon Ranksum and Kolmogorov-Smirnov) we determine the significance of both quantity and timing of events in southern California before and after large teleseismic events. To validate the use of our statistical tests, we first identify local mainshocks (M>3.2) with obvious aftershock sequences and local mainshocks (M>3.0) that lack an obvious aftershock sequence. Using our three statistical tests, we quantitatively confirm the triggering (non-triggering) nature of these local mainshocks and estimate a threshold required for triggering. Among local mainshocks, we find that triggering events generally reach higher spectral amplitudes than non-triggering events, particularly for frequencies in the range of 0.1 to 10 Hz. We assume that the same mechanism of triggering (i.e. amplitude, frequency or duration of ground motion) applies to both local and remote mainshocks. Applying the same tests and assumed triggering thresholds, we assess the ability of about 40 remote mainshocks (M>7.0) to trigger seismicity in southern California. We find no obvious signature of remote triggering. Comparing the spectral characteristics of local triggering mainshocks, local non-triggering mainshocks, and remote non-triggering mainshocks we reassess our threshold estimates. The results are complex, indicating that either: (1) the threshold triggering level is a complex combination of amplitude, frequency and duration; and/or (2) there is a time-to-failure component that we have not accounted for; and/or (3) different triggering mechanisms apply for remote and local events.
DE: 7209 Earthquake dynamics (1242)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
SC: Seismology [S]
MN: Fall Meeting 2005