Continuing megathrust earthquake potential in Chile after the 2014 Iquique earthquake

Nature
By: , and 

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Abstract

The seismic gap theory identifies regions of elevated hazard based on a lack of recent seismicity in comparison with other portions of a fault. It has successfully explained past earthquakes (see, for example, ref. 2) and is useful for qualitatively describing where large earthquakes might occur. A large earthquake had been expected in the subduction zone adjacent to northern Chile which had not ruptured in a megathrust earthquake since a M ~8.8 event in 1877. On 1 April 2014 a M 8.2 earthquake occurred within this seismic gap. Here we present an assessment of the seismotectonics of the March–April 2014 Iquique sequence, including analyses of earthquake relocations, moment tensors, finite fault models, moment deficit calculations and cumulative Coulomb stress transfer. This ensemble of information allows us to place the sequence within the context of regional seismicity and to identify areas of remaining and/or elevated hazard. Our results constrain the size and spatial extent of rupture, and indicate that this was not the earthquake that had been anticipated. Significant sections of the northern Chile subduction zone have not ruptured in almost 150 years, so it is likely that future megathrust earthquakes will occur to the south and potentially to the north of the 2014 Iquique sequence.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Continuing megathrust earthquake potential in Chile after the 2014 Iquique earthquake
Series title Nature
DOI 10.1038/nature13677
Volume 512
Year Published 2014
Language English
Publisher Nature Publishing Group
Contributing office(s) Geologic Hazards Science Center
Description 4 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Nature
First page 295
Last page 298
Country Chile
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