Authors: Ming Hao Qingliang Wang Liwei Liu Qi Shi
Publish Date: 2014/10/21
Volume: 59, Issue: 35, Pages: 5129-5135
Abstract
By using precise leveling data observed between 1985 and 2010 across the south section of the Longmenshan fault zone and eliminating the coseismic displacements caused by the Wenchuan Ms 80 earthquake the interseismic vertical deformation field was obtained The result shows that the Lushan region located between the Shuangshi–Dachuan fault front range of the Longmenshan fault and the Xinkaidian fault south section of the Dayi fault is situated in the intersection zone of positive and negative vertical deformation gradient zones indicating that this zone was locked within 25 years before the Lushan earthquake Based on leveling data across the rupture zone surveyed between 2010 and 2013 and by eliminating the vertical deformation within 3 years before the earthquake the coseismic vertical displacement was derived The coseismic vertical displacement for the benchmark DD35 which is closest to the epicenter is up to 1984 mm with respect to MY165A The coseismic displacement field revealed that the northwest region hanging wall moved upwards in comparison with the southeastern region foot wall suggesting that the seismogenic fault mainly underwent thrust faulting By comparing the coseismic and interseismic vertical deformation fields it was found that the mechanisms of this earthquake are consistent with the elastic rebound theory the elastic strain energy displacement deficit accumulated before the Lushan earthquake was released during this quakeThis work was supported by National Special Fund for Earthquake Scientific Research in Public Interest 201408014 201208009 and the National Natural Science Foundation of China 41174083 Some figures presented in this paper were prepared by the GMT software
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