2017 Valparaíso earthquake sequence and the megathrust patchwork of central Chile

Geophysical Research Letters
By: , and 

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Abstract

In April 2017, a sequence of earthquakes offshore Valparaíso, Chile, raised concerns of a potential megathrust earthquake in the near future. The largest event in the 2017 sequence was a M6.9 on 24 April, seemingly colocated with the last great-sized earthquake in the region—a M8.0 in March 1985. The history of large earthquakes in this region shows significant variation in rupture size and extent, typically highlighted by a juxtaposition of large ruptures interspersed with smaller magnitude sequences. We show that the 2017 sequence ruptured an area between the two main slip patches during the 1985 earthquake, rerupturing a patch that had previously slipped during the October 1973 M6.5 earthquake sequence. A significant gap in historic ruptures exists directly to the south of the 2017 sequence, with large enough moment deficit to host a great-sized earthquake in the near future, if it is locked.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title 2017 Valparaíso earthquake sequence and the megathrust patchwork of central Chile
Series title Geophysical Research Letters
DOI 10.1002/2017GL074767
Volume 44
Issue 17
Year Published 2017
Language English
Publisher AGU Publications
Contributing office(s) Geologic Hazards Science Center
Description 8 p.
First page 8865
Last page 8872
Country Chile
City Valparaiso