摘要
Focusing on the b-value as the research target and under the theoretical framework that the b-value is determined by stress state and medium properties, the variation characteristics of the b-value in the Hetao seismic belt are analyzed. Earthquakes with ML≥1. 5,which have occurred in the Hetao seismic belt since 1970 are selected to conduct the quantitative detection of the non-uniform temporal change of Mcusing the EMR method. Based on the actual situation of seismic activity,the lower limit magnitude is set as ML2. 0 to calculate the b-value. The temporal variation of the b-value is calculated and scanned using the least square method. The results show that there is a good corresponding relationship between the temporal variation of the b-value,strong earthquake activity,network distribution and aftershock deletion. We also calculate and scan the spatial variation of the b-value by using maximum likelihood. The results show that the spatial difference is possibly caused by stress state and crustal medium properties. The tectonic dependence of the b-value is obvious. In addition,the sufficient earthquakes samples in each magnitude interval are still a key step to improve the calculation accuracy of the b-value.
Focusing on the b-value as the research target and under the theoretical framework that the b-value is determined by stress state and medium properties, the variation characteristics of the b-value in the Hetao seismic belt are analyzed. Earthquakes with ML≥1. 5,which have occurred in the Hetao seismic belt since 1970 are selected to conduct the quantitative detection of the non-uniform temporal change of Mcusing the EMR method. Based on the actual situation of seismic activity,the lower limit magnitude is set as ML2. 0 to calculate the b-value. The temporal variation of the b-value is calculated and scanned using the least square method. The results show that there is a good corresponding relationship between the temporal variation of the b-value,strong earthquake activity,network distribution and aftershock deletion. We also calculate and scan the spatial variation of the b-value by using maximum likelihood. The results show that the spatial difference is possibly caused by stress state and crustal medium properties. The tectonic dependence of the b-value is obvious. In addition,the sufficient earthquakes samples in each magnitude interval are still a key step to improve the calculation accuracy of the b-value.
基金
sponsored by the Spark Program of Earthquake Sciences of China Earthquake Administration(XH15010 Y)
