Permanently enhanced dynamic triggering probabilities as evidenced by two M ≥ 7.5 earthquakes

Geophysical Research Letters



The 2012 M7.7 Haida Gwaii earthquake radiated waves that likely dynamically triggered the 2013M7.5 Craig earthquake, setting two precedents. First, the triggered earthquake is the largest dynamically triggered shear failure event documented to date. Second, the events highlight a connection between geologic structure, sedimentary troughs that act as waveguides, and triggering probability. The Haida Gwaii earthquake excited extraordinarily large waves within and beyond the Queen Charlotte Trough, which propagated well into mainland Alaska and likely triggering the Craig earthquake along the way. Previously, focusing and associated dynamic triggering have been attributed to unpredictable source effects. This case suggests that elevated dynamic triggering probabilities may exist along the many structures where sedimentary troughs overlie major faults, such as subduction zones’ accretionary prisms and transform faults’ axial valleys. Although data are sparse, I find no evidence of accelerating seismic activity in the vicinity of the Craig rupture between it and the Haida Gwaii earthquake.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Permanently enhanced dynamic triggering probabilities as evidenced by two M ≥ 7.5 earthquakes
Series title Geophysical Research Letters
DOI 10.1002/grl.50933
Volume 40
Issue 18
Year Published 2013
Language English
Publisher Americal Geophysical Union
Contributing office(s) Earthquake Science Center
Description 6 p.
First page 4828
Last page 4833
Country Canada, United States
State Alaska, British Columbia
Online Only (Y/N) N
Additional Online Files (Y/N) N
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