主题：最新研究：紫铺坪水库触发汶川地震 -- 大龙猫

Did the Zipingpu Reservoir trigger the 2008 Wenchuan earthquake?

Did the Zipingpu Reservoir trigger the 2008 Wenchuan earthquake?

Shemin Ge

Department of Geological Sciences, University of Colorado, Boulder, Colorado, USA

Mian Liu

Department of Geological Sciences, University of Missouri, Columbia, Missouri, USA

Ning Lu

Division of Engineering, Colorado School of Mines, Golden, Colorado, USA

Jonathan W. Godt

U.S. Geological Survey, Denver, Colorado, USA

Gang Luo

Department of Geological Sciences, University of Missouri, Columbia, Missouri, USA

The devastating May 2008 Wenchuan earthquake (Mw 7.9) resulted from thrust of the Tibet Plateau on the Longmen Shan fault zone, a consequence of the Indo-Asian continental collision. Many have speculated on the role played by the Zipingpu Reservoir, impounded in 2005 near the epicenter, in triggering the earthquake. This study evaluates the stress changes in response to the impoundment of the Zipingpu Reservoir and assesses their impact on the Wenchuan earthquake. We show that the impoundment could have changed the Coulomb stress by 0.01 to 0.05 MPa at locations and depth consistent with reported hypocenter positions. This level of stress change has been shown to be significant in triggering earthquakes on critically stressed faults. Because the loading rate on the Longmen Shan fault is <0.005 MPa/yr, we thus suggest that the Zipingpu Reservoir potentially hastened the occurrence of the Wenchuan earthquake by tens to hundreds of years.