[1]ZHANG Xi,ZHANG Sixin,QIN Shanlan,et al.Analysis of Crustal Deformation Joint Inversion for Preparation and Occurrence Process of the 2013 Minxian-Zhangxian MS6.6 Earthquake[J].Journal of Seismological Research,2019,42(01):40-48.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
42
Number of periods:
2019 01
Page number:
40-48
Column:
Public date:
2019-04-20
- Title:
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Analysis of Crustal Deformation Joint Inversion for Preparation and Occurrence Process of the 2013 Minxian-Zhangxian MS6.6 Earthquake
- Author(s):
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ZHANG Xi; ZHANG Sixin; QIN Shanlan; JIA Peng; LI Ruisha
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(The Second Monitoring and Application Center,China Earthquake Administration,Xi'an 710054,Shaanxi,China)
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- Keywords:
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joint 3D-negative dislocation inversion; the Minxian-Zhangxian earthquake; locking of fracture; dynamic variation of fracture activities
- CLC:
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P315.725
- DOI:
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- Abstract:
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Based on observational data of the regional leveling and long-distance leveling profiles at the Western Qinling Mountains tectonic area,combined with the GPS velocity field constraints and the cross-fault short-leveling observational data,we analyzed the middle and long term locking background of the related fractures before the 2013 Minxian-Zhangxian MS6.6 earthquake,and discussed the middle-short term dynamic and aftershock variation,aided by the first associated three-dimensional negative dislocation inversion. The results show that,the maximum shear strain rate,compressional surface strain rate and vertical gradient rate of the block between the West Qinling Mountains north edge fault and Lintan-Dangchang fault were larger during 1999 and 2007 before the earthquake. The three-dimensional difference movement,which was consistent with the tectonic and dynamic background,was obvious,which was beneficial to the accumulation of energy and the occurrence of strong earthquake. The middle segment of the West Qinling Mountains north edge fault containing the Zhangxian area,and the middle-eastern segment of Lintan-Dangchang fault which is the main fracture of seismic tectonic,displayed obvious locking feature,and the compressive reverse and left-lateral strike,showed the background of the medium and long term energy accumulation. Moreover,the long-distance leveling profile from the Zhangxian segment of the West Qinling Mountains north edge fault to the Minxian area of the middle-eastern segment of the Lintan-Dangchang fault,showed that the difference movement of the West Qinling Mountains north edge fault enhanced in two years before this earthquake,was consistent with that of the GPS observations. Several days before the earthquake,Sidian and Maoyugou sites located at these two faults reflected large short-impending suddenly change abnormity; after the earthquake,the vertical differential movement decreased and recovered.