The 13 November 2016 Kaikoura,New Zealand earthquake:rupture process and seismotectonic implications  

作　　者：Yi-Ching Lo Li Zhao XiWei Xu Ji Chen Shu-Huei Hung 

机构地区：[1]Department of Geosciences, National Taiwan University [2]School of Earth and Space Sciences, Peking University [3]Institute of Crustal Dynamics,China Earthquake Administration [4]Department of Earth Science, University of California,Santa Barbara, CA, U.S.A.

出　　处：《Earth and Planetary Physics》2018年第2期139-149,共11页地球与行星物理（英文版）

摘　　要：The 13 November 2016 Kaikoura earthquake occurred in the northeastern coastal region of the South Island, New Zealand. The M_w 7.8 mainshock generated a complex pattern of surface ruptures, and was followed within about 12 hours by three moderate shocks of M_w ≥ 6.0. Here we use teleseismic waveforms to invert for the source rupture of the Kaikoura earthquake. The resulting slip-distribution model exhibits insignificant slip near the hypocenter and three pockets of major slip zones with distinct senses of motion. The mainshock started from a rupture near the hypocenter, grew into thrust on shallow crustal faults ~50 km northeast of the hypocenter, and then developed into two slip zones: a deeper one with oblique thrust and a shallower one with almost purely right-lateral strike-slip. Locations of the thrust and strike-slip motions in the slip-distribution model agree well with reported coastal uplifts and horizontal offsets. The overall slip pattern is dominated by horizontal motion, especially at shallow depth, due to the partitioning of thrust and strike-slip motions above the subduction zone megathrust. Aftershock distribution suggests that most aftershocks tend to occur near the edges of the major slip zones of the mainshock. This observation on aftershock locations may provide useful information for seismic hazard assessments after large earthquakes.The 13 November 2016 Kaikoura earthquake occurred in the northeastern coastal region of the South Island, New Zealand. The M_w 7.8 mainshock generated a complex pattern of surface ruptures, and was followed within about 12 hours by three moderate shocks of M_w ≥ 6.0. Here we use teleseismic waveforms to invert for the source rupture of the Kaikoura earthquake. The resulting slip-distribution model exhibits insignificant slip near the hypocenter and three pockets of major slip zones with distinct senses of motion. The mainshock started from a rupture near the hypocenter, grew into thrust on shallow crustal faults ~50 km northeast of the hypocenter, and then developed into two slip zones: a deeper one with oblique thrust and a shallower one with almost purely right-lateral strike-slip. Locations of the thrust and strike-slip motions in the slip-distribution model agree well with reported coastal uplifts and horizontal offsets. The overall slip pattern is dominated by horizontal motion, especially at shallow depth, due to the partitioning of thrust and strike-slip motions above the subduction zone megathrust. Aftershock distribution suggests that most aftershocks tend to occur near the edges of the major slip zones of the mainshock. This observation on aftershock locations may provide useful information for seismic hazard assessments after large earthquakes.

关 键 词：SLIP DISTRIBUTION Kaikoura EARTHQUAKE AFTERSHOCK DISTRIBUTION SLIP partitioning 

分 类 号：P35[天文地球—空间物理学]