Loreto Intermediate Depth Earthquake of 26 May 2019 (Northeast Peru): Source Parameters by Inversion of Local to Regional Waveforms and Strong-Motion Observations

Description

Abstract The Loreto earthquake of 26 May 2019 occurred below the extreme northeast part of Peru at a depth of 140 km within the subducting Nazca plate at a distance of 700 km from the trench Peru–Chile. The orientation of the seismic source was obtained from waveform inversion in the near field using velocity and strong-motion data. The rupture occurred in normal faulting corresponding to a tensional process with T axis oriented in east–west direction similar to the direction of convergence between the Nazca and South America plates. The analysis of the strong-motion data shows that the levels of ground shaking are very heterogeneous with values greater than 50 Gal up to distances of 300 km; the maximum recorded acceleration of 122 Gal at a distance of 100 km from the epicenter. The Loreto earthquake is classified as a large extensional event in the descending Nazca slab in the transition from flat-slab geometry to greater dip.

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