【摘要】 利用云南省区域数字化观测资料,估算了2007年宁洱6.4级地震序列视应力,结果表明:①宁洱震区视应力在空间分布上明显呈NE向展布,视应力较高的地震大都分布在地震辐射能较高的地区;②宁洱6.4级主震发生的前4天,平均视应力为0.95MPa,主震发生4天以后,平均视应力为0.27MPa,恢复到云南平均背景应力水平;③视应力随拐角频率的增加而减小,大致呈负相关:lgσa=-0.36f+0.37,视应力与震源深度之间未发现明显的依赖关系。更多还原

【Abstract】 We calculated the apparent stress of the 2007 Ning’er,Yunnan,MS6.4 earthquake sequence using the data recorded by Yunnan Regional Digital Seismic Network. The result shows:(1) the apparent stress distributes obviously along NW-direction in the Ning’er earthquake area,and the earthquake with high apparent stress mostly locates in an area with high earthquake radiation energy;(2) within 4 days after the main shock,the average apparent stress is 0.95 MPa,after that it is 0.27 MPa,come back to the average apparent stress level of Yunnan;(3) the apparent stress reduces with increasing corner frequency,generally is negatively correlative:lgσa=-0.36f+0.37,and obvious dependent relation has not been found between the apparent stress and the focal depth.更多还原