甘东南地区水氡浓度的临界慢化现象研究

Critical-Slowing-Down Phenomenon of Water Radon Concentrations in the Southeastern Gansu Region

本文将临界慢化理论应用于甘东南地区水氡浓度观测资料的处理中,以2008年5月12日汶川MS8.0地震、2013年7月22日甘肃岷县—漳县MS6.6地震为例,计算表征临界慢化现象的自相关系数和方差。计算结果表明,甘东南地区多个台站的水氡浓度观测资料在两次地震前均存在较明显的临界慢化现象。并从空间分布、持续时间、变化形态方面分析了异常点水氡浓度变化的临界慢化特征,结合水氡异常的水动力学机制和异常点所在构造,认为2次地震前的临界慢化现象与地震的发生有一定关系。

In this study,we applied the critical-slowing-down principle to the processing of water radon concentration observation data in southeastern Gansu and calculated the autocorrelation coefficient and variance,which can characterize the critical-slowing-down.Here,we take the Wenchuan MS8.0 earthquake that occurred on May 12,2008,and the Minxian-Zhangxian MS6.6 earthquake that occurred on July 22,2013,as case studies.The results indicated that the water radon concentration at several stations in southeast Gansu showed the critical-slowing-down phenomenon before two earthquakes.Then we analyzed the characteristics of the critical-slowing-down of water radon concentration at abnormal points from the aspects of spatial distribution,duration,and change form.It is believed that the critical-slowing-down phenomenon before the two earthquakes was related to the earthquake occurrence by combining with the hydrodynamic mechanism of water radon anomalies and the structure of abnormal points.