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Depth‐dependent rupture mode along the Ecuador‐Colombia subduction zone
Author(s) -
Yoshimoto Masahiro,
Kumagai Hiroyuki,
Acero Wilson,
Ponce Gabriela,
Vásconez Freddy,
Arrais Santiago,
Ruiz Mario,
Alvarado Alexandra,
Pedraza García Patricia,
Dionicio Viviana,
Chamorro Orlando,
Maeda Yuta,
Nakano Masaru
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 - 10.1002/2016gl071929
Subject(s) - subduction , seismology , aftershock , geology , interplate earthquake , trench , episodic tremor and slip , asperity (geotechnical engineering) , intraplate earthquake , foreshock , slip (aerodynamics) , seismic gap , depth of focus (tectonics) , slow earthquake , fault (geology) , tectonics , geotechnical engineering , chemistry , physics , thermodynamics , organic chemistry , layer (electronics)
Abstract A large earthquake ( M w 7.7) occurred on 16 April 2016 within the source region of the 1906 earthquake in the Ecuador‐Colombia subduction zone. The 1906 event has been interpreted as a megathrust earthquake ( M w 8.8) that ruptured the source regions of smaller earthquakes in 1942, 1958, and 1979 in this subduction. Our seismic analysis indicated that the spatial distribution of the 2016 earthquake and its aftershocks correlated with patches of high interplate coupling strength and was similar to those of the 1942 earthquake and its aftershocks, suggesting that the 2016 and 1942 earthquakes ruptured the same asperity. Our analysis of tsunami waveforms of the 1906 event indicated M w around 8.4 and showed that large slip occurred near the trench off the source regions of the above three historical and the 2016 earthquakes, suggesting that a depth‐dependent complex rupture mode exists along this subduction zone.