Rupture process of the M_s 8.0 Wenchuan earthquake of Sichuan,China

On 12 May,2008 the great Wenchuan earthquake with magnitude Ms8.0 occurs on the Longmen Shan belt,which is located at the eastern margin of the Tibetan Plateau and northwestern Sichuan region of China.The strong shaking of the Wenchuan earthquake causes great disasters to life and property,and severe geologic damages,e.g.landslides and cracks to dams are inflicted.Based on the geologic studies and the surface rupture investigation,we constructed a more realistic double-listric finite-fault model,and reconstructed the source rupture process by combined inverting the teleseismic waveforms and local coseismic displacement.Results show that the Wenchuan earthquake is characterized mainly by thrust motion with right-lateral strike slip also,and two faults-Yingxiu-Beichuan fault and Guanxian-Jiangyou fault participated simultaneously during the rupture process.The estimated maximum slip on the fault can reach up to 12~12.5 m,and the distribution of slip on the faults with high magnitude can be projected to Yingxiu and Beichuan county which are severely damaged.The average strike-slip motion is a little larger than the slip motion,which is coincident with the deformation observation along the Longmen Shan tectonic region.The long-time regional stress accumulation,the composition of this region and special tectonic structure might be the reason for this great Wenchuan earthquake with recurrence interval of thousand years.