摘要
在较大地震的酝育过程中,随着构造岩体弹性应变能的不断积累,可能出现各项地球物理场观测量不同程度的前兆异常变化,这些复杂的异常变化具有序性特征。本文将信息熵引入地震前兆观测数据的分析处理,定量研究了一定区域内较大地震前地下水氡观测的信息熵变化。结果表明,震前信息熵有明显的低值异常出现,从一个侧面反映了较大地震前震源系统从无序到有序的演化过程。
During the preparedness process of larger earthquakes, there probably appear different degrees of precursory anomaly variations of observational quantities of geophysical field of the focal system as the successive accumulation of the elastic strain energy of the tectonic rock mass. These anomalous changes often show different characteristics of variation before various earthquakes. So the seismic precursors become a complex system. This paper introduced the information entropy into the analysis and processing of the precursory observation data so as to describe the complexity of the seismic precursory anomaly quantitatively from the angle of orlering of the system. Through the computation and process of the groungwater radon data in Urumuqi No. 10 well, results show that there appear obvious low-value anomalies for the information entropy before many earthquakes M≥5.0 around stations, and to a certain degree, this reflects that the focal system geophysical field changes from disordered anomalies to ordered anomalies before larger earthquakes.The computation of the information entropy maily lies in the selection of probability. In this reseach, authors use the empirical distribution prabability P i to derive the information entropy value. In the calculation, the time windows of 10, days, 20 days and 30 days were chosen to carry out the scanning-slip computation. It can be seen from the abnormal corresponding effect that under the three time windows, the entropy values synchronously reflect the precursory anomaly variation of the information entropy before shocks, but the variation features of the entropy value r.urves of the ten-day time window are relatively clear and audiovisual.
出处
《地震》
CSCD
北大核心
1991年第5期13-18,共6页
Earthquake
