Temporal variation of tectonic tremor activity in southern Taiwan around the 2010 ML6.4 Jiashian Earthquake

Journal of Geophysical Research B: Solid Earth
By: , and 

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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 spatio-temporal relationship between tremor and the 4 March 2010 ML6.4 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 mainshock, 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 mainshock, 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 pre-nucleation process of a nearby earthquake.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Temporal variation of tectonic tremor activity in southern Taiwan around the 2010 ML6.4 Jiashian Earthquake
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1002/2016JB013925
Volume 122
Issue 7
Year Published 2018
Language English
Publisher Wiley
Contributing office(s) Volcano Science Center
Description 18 p.
First page 5417
Last page 5434
Country Taiwan