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Slip history of the 2016 M w 7.0 Kumamoto earthquake: Intraplate rupture in complex tectonic environment
Author(s) -
Hao Jinlai,
Ji Chen,
Yao Zhenxin
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 - 10.1002/2016gl071543
Subject(s) - geology , seismology , intraplate earthquake , asperity (geotechnical engineering) , slip (aerodynamics) , sinistral and dextral , fault trace , fault (geology) , earthquake rupture , tectonics , geodesy , physics , geotechnical engineering , thermodynamics
Rupture history of the 2016 M w 7.0 Kumamoto earthquake is constrained by using the waveforms of strong motion observations, teleseismic broadband body waves, and long‐period surface waves. Its fault geometry is modeled with Hinagu (orienting 205° and dipping 73°) and Futagawa (orienting 235° and dipping 60°), two segments. The result reconciles the difference between moment tensor solutions and the surface fault trace. It reveals a complex rupture process that initiated on the Hinagu segment in dextral motion, propagated northeastward unilaterally, and after 15 s ceased near Aso volcano with normal fault motion. The average slip, rise time, and slip rate are 1.8 m, 2.0 s, and 1.2 m/s, respectively. The rupture broke through an ~30° fault intersection without notable delay, which can be a result of dynamic “unclamping.” The northeast boundary of the largest asperity might mark the bottom of the seismogenic zone, which becomes shallower gradually near Aso volcano.