The 19 September 2017 (M w 7.1) Intermediate-Depth Mexican Earthquake: A Slow and Energetically Inefficient Deadly Shock
Por:
Mirwald, Aron, Cruz-Atienza, Victor M., Diaz-Mojica, John, Iglesias, Arturo, Singh, Shri K., Villafuerte, Carlos, Tago, Josue
Publicada:
1 ene 2019
Resumen:
We investigate dynamic source parameters of the M w 7.1 Puebla-Morelos intermediate-depth earthquake (h = 57 km) of 19 September 2017, which devastated Mexico City. Our simple, elliptical source model, coupled with a new Particle Swarm Optimization algorithm, revealed rupture propagation within the subducted Cocos plate, featuring a high stress drop ( t = 14.9±5.6 MPa) and a remarkably low radiation efficiency (? r = 0.16 ± 0.09). Fracture energy was large (G = (1.04 ± 0.3) × 10 16 J), producing a slow dissipative rupture (V r /V s = 0.34 ± 0.04) with scaling-consistent radiated energy (E r = (1.8 ± 0.9)·10 15 J) and energy-moment ratio (E r /M 0 = 3.2 × 10 -5 ). About 84% of the available potential energy for the dynamic rupture was dissipated in the focal region, likely producing friction-induced melts in the fault core of 0.2–1.2 cm width due to heat production (700–1200 °C temperature rise). Such source features seem to be a universal signature of intermediate-depth earthquakes. ©2019. American Geophysical Union. All Rights Reserved.
Filiaciones:
Mirwald, Aron:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Cruz-Atienza, Victor M.:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Diaz-Mojica, John:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Iglesias, Arturo:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Singh, Shri K.:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Villafuerte, Carlos:
Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico
Tago, Josue:
Facultad de Ingeniería, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Fac Ingn, Mexico City, DF, Mexico
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