对1937年托索湖7.5级地震若干问题的探讨

1937年托索湖7.5级地震发生在东昆仑活动断裂带的东段,前人曾对该地震组织过4次不同程度的考察,并得出了4种不同的结果。带着上述问题对该地震地表破裂带重新进行了实地考察、测量和综合研究,然后对该地震地表破裂带的西端点、最大左旋水平位移量、最大垂直位移量、宏观震中等问题进行了重新厘定,认为1937年托索湖7.5级地震地表破裂带西端点在阿拉克湖以西,长度至少为240km,最大左旋水平位移量为8m,垂直位移量为3.5m,宏观震中在三岔口一带

THE DISCUSSION ON SOME PROBLEMS OF THE M_S7.5 TUOSUOHU LAKE EARTHQUAKE IN 1937

The East Kunlun active fault zone, which lies in the valley of the Kunlun Mountains above the elevation of 4,000 meters, is an important active fault in the Northeast Tibetan Plateau. The Tuosuohu Lake earthquake of magnitude 7.5 in 1937 occurred in the eastern segment of the East Kunlun active fault zone. Four field investigations have been launched on this seism in 1963,1971 and between 1986 and 1990 respectively, and four different conclusions have been gained. From the length aspect of the surface deformation zone of this earthquake, it is commonly recognized that its east end lies in the west side of the main Ridge of Animaqing Mountains; the opinion about the west end and the location of the macro-epicenter is different. Based on our investigation and comprehensive study, a series scientific problems like geometric and kinetic characteristics, the length of the rupture zone, the maximum sinistrally horizontal displacement and the macro-epicenter were reestimated. It is considered that the total length of this zone should be at least 240km; the maximum sinistrally horizontal displacement is 8m, the maximum vertical displacement is 3.5m; the macro-epicenter is in Sanchakou.