The 26 May 2019 MW 8.0 Intermediate Depth Peru Earthquake
Abstract
The 26 May 2019 MW 8.0 Peru earthquake struck within the nearly-horizontal underthrust Nazca plate about 123 km below the upper Amazon, near a steep bend in the plate where it plunges down to the deep earthquake zone under eastern Peru and western Brazil. Little prior seismicity occurred in the immediate source region, but large events in the horizontal slab have struck to the west. The event ruptured unilaterally northward with a rupture velocity of about 3 km/s, with patchy normal-faulting slip of up to 4 m spread along a 170 km long rupture zone, revealed by array back-projection images and teleseismic finite-fault inversion. The Peru event is situated in a similar slab position to the 2017 Puebla-Morelos Mexico earthquake, but its remote location resulted in limited loss of life and modest damage. Despite the mainshock size, the earthquake produced only two aftershocks detected by the USGS National Earthquake Information Center (mb 4.8 and 4.9); a remarkably low productivity consistent with the generally low productivity of subduction zones along western South America. We consider the implications of this large rupture and the lack of aftershock activity relative to other major intermediate depth events.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.S54B..08Y
- Keywords:
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- 7299 General or miscellaneous;
- SEISMOLOGY