Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Tidal stress triggering of earthquakes in Southern California
Author: Bucholc, M.
Steacy, S.
Citation: Geophysical Journal International, 2016; 205(2):681-693
Publisher: Oxford University Press
Issue Date: 2016
ISSN: 0956-540X
Statement of
Magda Bucholc and Sandy Steacy
Abstract: We analyse the influence of the solid Earth tides and ocean loading on the occurrence time of Southern California earthquakes. For each earthquake, we calculate tidal Coulomb failure stress and stress rate on a fault plane that is assumed to be controlled by the orientation of the adjacent fault. To reduce bias when selecting data for testing the tide-earthquake relationship, we create four earthquake catalogues containing events within 1, 1.5, 2.5 and 5 km of nearest faults. We investigate the difference in seismicity rates at times of positive and negative tidal stresses/stress rates given three different cases. We consider seismicity rates during times of positive versus negative stress and stress rate, as well as 2 and 3 hr surrounding the local tidal stress extremes. We find that tidal influence on earthquake occurrence is found to be statistically non-random only in close proximity to tidal extremes meaning that magnitude of tidal stress plays an important role in tidal triggering. A non-random tidal signal is observed for the reverse events. Along with a significant increase in earthquake rates around tidal Coulomb stress maxima, the strength of tidal correlation is found to be closely related to the amplitude of the peak tidal Coulomb stress (τp). The most effective tidal triggering is found for τp ≥ 1 kPa, which is much smaller than thresholds suggested for static and dynamic triggering of aftershocks.
Keywords: Time-series analysis; tides and planetary waves; earthquake dynamics; seismicity and tectonics
Rights: © The Authors 2016. Published by Oxford University Press on behalf of The Royal Astronomical Society.
RMID: 0030047582
DOI: 10.1093/gji/ggw045
Appears in Collections:Geology & Geophysics publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.