HR: 1340h
AN: S33C-1461    [Abstracts]
TI: Searching for Dynamical Earthquake Precursors with Surrogate Data
AU: * Lynch, J
EM: lynch197@umn.edu
AF: Brain Sciences Center Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, United States
AU: * Lynch, J
EM: lynch197@umn.edu
AF: Department of Neuroscience University of Minnesota, 6-145 Jackson Hall 321 Church Street, Minneapolis, MN 55455, United States
AU: Revenaugh, J
EM: justinr@umn.edu
AF: Department of Geology and Geophysics University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455, United States
AU: Georgopoulos, A
EM: omega@umn.edu
AF: Brain Sciences Center Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, United States
AU: Georgopoulos, A
EM: omega@umn.edu
AF: Department of Neuroscience University of Minnesota, 6-145 Jackson Hall 321 Church Street, Minneapolis, MN 55455, United States
AB: Surrogate data methods are resampling techniques related to the modern statistical bootstrap. The nonlinear dynamics community has promoted surrogate data as a useful tool for establishing the presence of nonlinear dynamics in experimental observations before applying more specific techniques such as nonlinear prediction. We propose to use surrogate data tests to search for evidence of transient nonlinear dynamics in seismographic data that act as a proxy for earthquake triggering mechanisms, such as fluid flow in the fault zone, failure cascades and slow prefatory slip, that signal changes in the coupling between geological boundaries. We will analyze the vertical component of broadband seismographic data recorded at 20Hz by the CI network of approximately 100 stations located throughout Southern California. We will focus on a period of six hours prior to seismic events of magnitude 4-5 located inside the CI network. Each seismographic record will be scanned for short, non-overlapping segments that pass a moderate stationarity criterion. We will then apply surrogate tests to each qualifying segment using three discriminating statistics: time reversal asymmetry, delay vector variance and zeroth-order nonlinear prediction error. We will correlate the results with known seismic activity and examine the spatial and temporal distribution of the surrogate test results for potential dynamical earthquake precursors.
DE: 0520 Data analysis: algorithms and implementation
DE: 3270 Time series analysis (1872, 4277, 4475)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
SC: Seismology [S]
MN: 2007 Fall Meeting