Dynamic responses of the Xianshuihe and Longmenshan fault zones to regional tectonic loading
Author(s): WANG Xiao-Fang, XIAO Jie, XU He-Hua, HE Jian-Kun, Key Laboratory of the Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Pages: 1403-1413
Year: 2016 Issue: 4
Journal: Chinese Journal of Geophysics
Keyword: Wenchuan earthquake; Longmenshan fault zone; Xianshuihe fault zone; Coulomb failure stress; Finite element modeling;
Abstract: In order to study the trigger interaction between the Wenchuan earthquake and the earthquakes on the Xianshuihe fault zone as well as the stress changing with the effect of regional tectonic loading,we have studied the seven major earthquakes in the Xianshuihe and Longmenshan fault zones.The regional tectonic loading is approximated by velocity boundaries from GPS data.The split-node technique was used to simulate the earthquakes in upper crust. With the threedimensional viscoelastic finite element code we simulated the evolution of Coulomb stress.The results show that the trigger interaction between the Wenchuan earthquake and the earthquakes on Xianshuihe fault zone is different.The trigger interaction is obvious on the Xianshuihe fault zone(except the Litang earthquake in 1948 and the Luhuo earthquake in 1973),as 17 to 38percentages′Coulomb stress increasing was caused by regional tectonic loading,other49 to 67percentages of stress was contributed by earthquake deformation.However,part of theCoulomb stress was released by the earthquakes that happened from 1893 to 1981.So it is impossible that the Wenchuan earthquake was triggered by the earthquakes in the past.The Coulomb stress in the Wenchuan earthquake was mainly increased from regional tectonic loading.With occurrence of this earthquake,the certain region released almost all the Coulomb stress and became into a new condition.
Pages: 1403-1413
Year: 2016 Issue: 4
Journal: Chinese Journal of Geophysics
Keyword: Wenchuan earthquake; Longmenshan fault zone; Xianshuihe fault zone; Coulomb failure stress; Finite element modeling;
Abstract: In order to study the trigger interaction between the Wenchuan earthquake and the earthquakes on the Xianshuihe fault zone as well as the stress changing with the effect of regional tectonic loading,we have studied the seven major earthquakes in the Xianshuihe and Longmenshan fault zones.The regional tectonic loading is approximated by velocity boundaries from GPS data.The split-node technique was used to simulate the earthquakes in upper crust. With the threedimensional viscoelastic finite element code we simulated the evolution of Coulomb stress.The results show that the trigger interaction between the Wenchuan earthquake and the earthquakes on Xianshuihe fault zone is different.The trigger interaction is obvious on the Xianshuihe fault zone(except the Litang earthquake in 1948 and the Luhuo earthquake in 1973),as 17 to 38percentages′Coulomb stress increasing was caused by regional tectonic loading,other49 to 67percentages of stress was contributed by earthquake deformation.However,part of theCoulomb stress was released by the earthquakes that happened from 1893 to 1981.So it is impossible that the Wenchuan earthquake was triggered by the earthquakes in the past.The Coulomb stress in the Wenchuan earthquake was mainly increased from regional tectonic loading.With occurrence of this earthquake,the certain region released almost all the Coulomb stress and became into a new condition.
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