Constraints on Rupture Speed of the 2001 M_S8.1 Western Kunlun Mountain Pass Earthquake by Co-Seismic Surface Rupture Slip Displacements Based on the Slip-Weakening Mechanism with Frictional Undershoot Involved

详细信息   

• 责任者：Shi Baoping (College of Earth Science ; Graduate University of Chinese Academy of Sciences ; Beijing 100049 ; China) ; Yang Yong
• 刊名：Acta Seismologica Sinica
• 出版年：2008
• 卷期：30(3)
• 关键词：震源机制 ; focal mechanism ; 昆仑山口西地震 ; west of Kunlun Mountains Pass earthquake 2001 ; 昆仑山 ; Kunlun Mountains
• 页码：p.217-229
• 图表：5 illus., 2 tables, 49 refs.
• 分类号：0500
• issnNo：ISSN0253-3782
• isbnNo：CN11-2021/P

摘要

///With the co-seismic surface rupture slip displacements provided by the field observation for the 2001 M_S8.1 Western Kunlun Mountain Pass earthquake, this paper estimate the rupture speed on the main faulting segment with a long straight fault trace on the surface based on the simple slip-weakening rupture model, in which the frictional overshoot or undershoot are involved in the consideration of energy partition during the earthquake faulting. In contrast to the study of Bouchon and Vallee in which the rupture propagation along the main fault could exceed the local shear-wave speed, perhaps reach the P-wave speed on a certain section of the fault, the results show that, under the slip-weakening assumption combined with a frictional undershoot (partial stress drop model), the average rupture speed should be equal to or less than the Rayleigh wave speed with a high seismic radiation efficiency, which is consistent with the result derived by waveform inversion and the result estimated from source stress field. In consideration of the surface rupture behavior, such as partial stress drop (frictional undershoot) associated with the apparent stress, an alternative rupture mechanism based on the slip-weakening model has also been discussed in this paper.