2017-08-09精河6.6级地震序列视应力特征研究

Apparent Stress Characteristics of Jinghe MS6.6 Earthquake Sequence on Aug 9,2017

利用新疆区域数字化观测资料计算2017-08-09精河6.6级地震序列的视应力值,讨论主震视应力与震源机制解类型及余震视应力、拐角频率和震级的关系。结果表明:1)精河6.6级地震主震视应力大小与震源机制解无相关性,主震视应力值高于余震视应力值,余震视应力和震级存在对数正相关关系,拐角频率与震级存在一定的负相关关系;2)主震后7 h内视应力处于整个序列的高值阶段,且发生了多次强余震,这可能是受到震后应力调整的影响;3)天山中段6级地震序列中均存在强余震前视应力值高值现象,强余震发生后视应力值恢复到低值水平。

Based on the earthquake data recorded by Xinjiang digital seismic network,we calculate the apparent stress of the Jinghe,Xinjiang Aug 9,2017 M S6.6 earthquake sequence.We discuss the relationship between the apparent stress of the major earthquake and the focal mechanism solution.We also discuss the relationship between the aftershock earthquake apparent stress,corner frequency and earthquake magnitude.The results show:1)There is no correlation between apparent stress and focal mechanism solution,the apparent stress of the major earthquake is higher than the aftershock earthquakes,and there is positive correlation between apparent stress and earthquake magnitude,and a negative correlation between corner frequency and earthquake magnitude;2)7 hours after the main shock,the apparent stress is higher in the sequence and strong aftershock,depending on the stress adjustment after strong earthquake;3)the apparent stress before strong aftershock earthquakes is higher,returning to the low level after strong aftershock.This phenomenon also occurred in other M S6.0 earthquake sequence in middle Tianshan.