Premium
Temporal variation of tectonic tremor activity in southern Taiwan around the 2010 M L 6.4 Jiashian earthquake
Author(s) -
Chao Kevin,
Peng Zhigang,
Hsu YaJu,
Obara Kazushige,
Wu Chunquan,
Ching KuoEn,
Lee Suzan,
Pu HsinChieh,
Leu PeihLin,
Wech Aaron
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2016jb013925
Subject(s) - seismology , geology , tectonics , slip (aerodynamics) , global positioning system , episodic tremor and slip , fault (geology) , shock (circulatory) , geodesy , subduction , physics , medicine , telecommunications , computer science , thermodynamics
Abstract Deep tectonic tremor, which is extremely sensitive to small stress variations, could be used to monitor fault zone processes during large earthquake cycles and aseismic processes before large earthquakes. In this study, we develop an algorithm for the automatic detection and location of tectonic tremor beneath the southern Central Range of Taiwan and examine the spatiotemporal relationship between tremor and the 4 March 2010 M L 6.4 Jiashian earthquake, located about 20 km from active tremor sources. We find that tremor in this region has a relatively short duration, short recurrence time, and no consistent correlation with surface GPS data. We find a short‐term increase in the tremor rate 19 days before the Jiashian main shock, and around the time when the tremor rate began to rise one GPS station recorded a flip in its direction of motion. We hypothesize that tremor is driven by a slow‐slip event that preceded the occurrence of the shallower Jiashian main shock, even though the inferred slip is too small to be observed by all GPS stations. Our study shows that tectonic tremor may reflect stress variation during the prenucleation process of a nearby earthquake.