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Composite Megathrust Rupture From Deep Interplate to Trench of the 2016 Solomon Islands Earthquake
Author(s) -
Lee ShiannJong,
Lin TzuChi,
Feng KuanFu,
Liu TingYu
Publication year - 2018
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 - 10.1002/2017gl076347
Subject(s) - geology , subduction , seismology , trench , asperity (geotechnical engineering) , slip (aerodynamics) , interplate earthquake , tsunami earthquake , intraplate earthquake , episodic tremor and slip , convergent boundary , pacific plate , fault (geology) , depth of focus (tectonics) , earthquake rupture , tectonics , oceanic crust , geotechnical engineering , layer (electronics) , chemistry , physics , organic chemistry , thermodynamics
The deep plate boundary has usually been recognized as an aseismic area, with few large earthquakes occurring at the 60–100 km depth interface. In contrast, we use a finite‐fault rupture model to demonstrate that large slip in the 2016 M 7.9 Solomon Islands earthquake may have originated from the deep subduction interface and propagated all the way up to the trench. The initial rupture occurred at a depth of about 100 km, forming a deep asperity and then propagating updip to the middle‐depth large coseismic slip area. Our proposed source model indicates that the depth‐varying rupture characteristics of this event could shift to deeper depths with respect to other subduction zones. This result also implied that the deep subducting plate boundary could also be seismogenic, which might trigger rupture at the typical middle‐depth stress‐locked zone and develop into rare composite megathrust events.