ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Helmberger, Donald V. ; Tromp, Jeroen ; Rodgers, Arthur J.

California Institute of Technology

关键词: Calibration;    Monitoring;    Wave Forms;    Simulation;    58 Geosciences;   

DOI  :  10.2172/950710
RP-ID  :  DOE DE-FC52-06NA27319
RP-ID  :  FC52-06NA27319
RP-ID  :  950710

美国|英语

来源: UNT Digital Library

【 摘 要 】

Abstract We conduct a detailed test of a recently developed technique, CAPloc, in recovering source parameters from a few stations against results from a large broadband network in Southern California. The method uses a library of 1D Green’s functions which are broken into segments and matched to waveform observations with adjustable timing shifts. These shifts can be established by calibration against a distribution of well-located earthquakes and assembled in tomographic images for predicting various phase-delays. Synthetics generated from 2D cross-sections through these models indicates that 1D synthetic waveforms are sufficient in modeling but simply shifted in time for most hard-rock sites. This simplification allows the source inversion for both mechanism and location to easily obtain by grid search. We test one-station mechanisms for 160 events against the array for both PAS and GSC which have data since 1960. While individual solutions work well (about 90%), joint solutions produce more reliable and defensible results. Inverting for both mechanism and location also works well except for certain complex paths across deep basins and along mountain ridges.