Back to full interseismic plate locking decades after the giant 1960 Chile earthquake

Nature Communications
By: , and 

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Abstract

Great megathrust earthquakes arise from the sudden release of energy accumulated during centuries of interseismic plate convergence. The moment deficit (energy available for future earthquakes) is commonly inferred by integrating the rate of interseismic plate locking over the time since the previous great earthquake. But accurate integration requires knowledge of how interseismic plate locking changes decades after earthquakes, measurements not available for most great earthquakes. Here we reconstruct the post-earthquake history of plate locking at Guafo Island, above the seismogenic zone of the giant 1960 (Mw = 9.5) Chile earthquake, through forward modeling of land-level changes inferred from aerial imagery (since 1974) and measured by GPS (since 1994). We find that interseismic locking increased to ~70% in the decade following the 1960 earthquake and then gradually to 100% by 2005. Our findings illustrate the transient evolution of plate locking in Chile, and suggest a similarly complex evolution elsewhere, with implications for the time- and magnitude-dependent probability of future events.

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Publication type Article
Publication Subtype Journal Article
Title Back to full interseismic plate locking decades after the giant 1960 Chile earthquake
Series title Nature Communications
DOI 10.1038/s41467-018-05989-6
Volume 9
Year Published 2018
Language English
Publisher Nature Publishing Group
Contributing office(s) Geologic Hazards Science Center
Description Article number: 3527; 10 p.
Country Chile
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