Residual strain explains later quakes

The largest earthquake in recorded history struck southern Chile on May 22, 1960. The magnitude-9.5 temblor was followed by a tsunami that, combined with the seismic shaking, killed 1,600 people and left more than 2 million homeless. New research suggests that, despite the staggering size of the event, the shaking didn’t dissipate all the strain accumulated at the time on the subduction fault between the Nazca and South American tectonic plates. The residual strain left on the fault may explain why a portion of this same section of fault ruptured again — 56 years later — on Dec. 25, 2016, in a magnitude-7.6 event.

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Mary Caperton Morton

Mary Caperton Morton

Morton (https://theblondecoyote.com/) is a freelance science and travel writer based in Big Sky, Mont., and an EARTH roving correspondent.  

Monday, March 26, 2018 - 06:00