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Journal: |
Journal of Geophysical Research 2019 No.5
clicks:278 |
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Title:
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Author:
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Gang Liu1,2 , Wei Xiong1,3, Qi Wang2 , Xuejun Qiao1 , Kaihua Ding4 , Xingxing Li3 , and ShaoMin Yang1 |
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Adress: |
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Abstract:
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On 8 August 2017, a strong earthquake occurred on an unmapped extension of the Huya fault,
Sichuan, China, causing severe damage to local communities. This event highlights the northward
migration of major earthquakes along a single strike‐slip fault. We analyze the source characteristics with
Global Positioning System (GPS)/ Interferometric Synthetic Aperture Radar static displacements and
high‐rate GPS/teleseismic dynamic motions. Our analyses show a complex slip pattern characterized by two
patches with a mean slip of 0.6 m and predominantly strike‐slip components. Slip propagates at a
rupture speed of approximately 3.2 km/s for about 30 km in length and 20 km in width. Given a slip rate of
0.5 mm/year derived from GPS observations, the mean slip of 0.6 m inferred from the slip model suggests
a recurrence interval of ~1,000 years for this earthquake and alike on the Huya fault. The Coulomb stress
increase of 0.82 bar caused by preceding earthquakes promoted the failure of the northern Huya fault in
2017. In particular, the nucleation of this event was partially facilitated by the 2008 Wenchuan earthquake
and postseismic deformation. Long‐term slip deficits on most parts of the Huya fault have been balanced
largely by a series of strong earthquakes since the early 1970s. As yet, a few of seismic gaps remain hazardous
during the final stage of one seismic cycle. In particular, the ongoing postseismic relaxation will hasten
further the 20‐ to 25‐km long segment in the Jiuzhaigou National Natural Reserve closer to failure in a
moderate size earthquake. |
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