鲜水河断裂带现今断层运动短周期事件的发现与初步研究

DISCOVERY AND PRELIMINARY RESEARCH FOR SHORT-PERIOD PHENOMENA OF PRESENT-DAY FAULT MOVEMENT ON XIANSHUIHE FAULT ZONE

根据鲜水河断裂带上连续动态地壳形变台阵数据，首次揭示了中国大陆板内断层现今运动的短周期现象，包括蠕变阶、蠕变坡和脉动等，其持续时间为数分钟至数十小时。发现其空间分布与断层分段（闭锁或活动段）有关；其时间分布与强地震孕育过程有关。蠕变过程符合Ｌｏｍｎｉｚ提出的对数蠕变函数，可能是断层面不均匀结构中的局部流变行为。断层短周期事件对揭示断层不均匀结构和微破裂过程动力学有重要意义。

According to the data for the continuous and dynamic crust deformation observation array on Xianshuihe fault zone,the short period phenamena of intraplate fault present-day movement in the continent of China, including creep step,creep gradient and pulsation,are firstly uncovered. Their duration time range is from minutes to tens hours, the spatial distribution is relevant to the fault′s segmentation (closed or active part),and the temporal distribution to the seismogenic process of strang earthquake. The creep process coincides with Lomniz's Logarithmic creep function, it may be due to the local rheologic behavior in inhomogeneous structure of the fault plane. The short period events of faults have important significance for exposing the fault inhomogeneous structure and micro-fracture process dynamics, and can develop into a new earthquake precursor.