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Inherited State of Stress as a Key Factor Controlling Slip and Slip Mode: Inference From the Study of a Slow Slip Event in the Longitudinal Valley, Taiwan
Author(s) -
Canitano Alexandre,
Godano Maxime,
Thomas Marion Y.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl090278
Subject(s) - slip (aerodynamics) , seismology , geology , borehole , episodic tremor and slip , induced seismicity , subduction , geotechnical engineering , physics , tectonics , thermodynamics
Using borehole strainmeters, we detected a 13‐day long slow slip event in 2011 with M w = 5.45 on the Longitudinal Valley Fault, Taiwan. It has been likely promoted by the significant Coulomb stress changes (∼0.5–1 MPa) imparted by a combination of coseismic and postseismic slip of the 2003 Chengkung earthquake. Using kinematic slip models, we infer that the slow event has accommodated about 15%–35% of the slip deficit accumulated from 1997 to 2011 in its source region. Further, we find that inherited state of stress may have controlled the slow event southward propagation. We also highlight a spatiotemporal correlation between the slow event and a cluster of repeating microearthquakes, suggesting a complex interplay between seismic and aseismic processes on the fault, where transient aseismic regions are adjacent to highly coupled zones.