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The 2017 M w 8.2 Chiapas, Mexico, Earthquake: Energetic Slab Detachment
Author(s) -
Ye Lingling,
Lay Thorne,
Bai Yefei,
Cheung Kwok Fai,
Kanamori Hiroo
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl076085
Subject(s) - geology , seismology , subduction , slab , trench , lithosphere , intraplate earthquake , interplate earthquake , slip (aerodynamics) , seismic moment , fault (geology) , geophysics , tectonics , chemistry , physics , organic chemistry , layer (electronics) , thermodynamics
On 8 September 2017, a great ( M w 8.2) normal faulting earthquake ruptured within the subducting Cocos Plate ~70 km landward from the Middle American Trench beneath the Tehuantepec gap. Iterative inversion and modeling of teleseismic and tsunami data and prediction of GPS displacements indicate that the steeply dipping rupture extended ~180 km to the northwest along strike toward the Oaxaca coast and from ~30 to 70 km in depth, with peak slip of ~13 m. The rupture likely broke through the entire lithosphere of the young subducted slab in response to downdip slab pull. The plate boundary region between the trench and the fault intersection with the megathrust appears to be frictionally coupled, influencing location of the detachment. Comparisons of the broadband body wave magnitude ( m B ) and moment‐scaled radiated energy ( E R /M 0 ) establish that intraslab earthquakes tend to be more energetic than interplate events, accounting for strong ground shaking observed for the 2017 event.