摘要
快速、精确地进行震源定位是地震学的基础性研究课题之一.为了满足目前相关地震工作的需要,找到一种与实际情况相适应的有效震源定位方法具有切实意义.本文研究了干涉成像方法,根据地下介质构造以及对应传播速度,利用干涉的方法对震源位置进行成像.这种算法对地震记录的要求较低,不需要精确的初至时间,适应于多震源延时激发且信噪比较低的微震定位.基于二维干涉定位我们得到了三维干涉定位方法,确定了对应的成像理论.首先在二维水平层状介质模型中测试,定位结果趋近模拟位置.之后建立了三维均匀介质模型,进行三维弹性波场的数值模拟,对接收到的数据进行互相关运算,利用结果进行干涉成像,可以得到较为精确的水平位置,再结合二维模型中的方法确定深度,定位结果与模拟震源相符.最后根据三维模型下的微震数据同时定位出多个微震震源,证实了算法在微震定位中切实有效.
Source location which is fast and accurate is one of the basis research subject of Seismology. In order to meet the needs of the relevant seismic work,it is significant to find an effective source location method which is suitable for the actual situation. In this paper,we do some research on the interferometric seismic imaging,according to the structure of underground medium and the corresponding propagation velocity,the source location is imaged by the method of interference. This algorithm does not require an accurate seismic recording and the beginning of the time. It is suitable for the micro seismic with weak energy and sources which is delay excited. Based on the 2D interferometric locating method,we obtained the 3D interferometric locating method. After combining the two methods,we have identified 3D imaging theory that provides two directional positioning results. At first,the location results are close to the simulated position in a 2D horizontal layered medium model. After that, we complete a numerical simulation in the establishment of 3D homogeneous model with elastic wave. We get the cross-correlograms of received data, and complete the interferometric seismic imaging. We can get a horizontal accurate position,and then determine the depth combined with the method which is used in the 2D model. The positioning results are consistent with the simulation source. After improving the accuracy of the results,the error is evaluated. Finally,a number of microseismic sources are located according to the micro-seismic data of the three-dimensional model,which proves that the algorithm is effective in micro-seismic localization.
出处
《地球物理学进展》
CSCD
北大核心
2017年第6期2460-2465,共6页
Progress in Geophysics
基金
国家科技重大专项项目(2016ZX05026-002-003)
国家自然科学基金项目(41374108)联合资助
关键词
三维
震源定位
互相关
微震
three-dimensional
source location
cross-correlation
micro-seismic
