摘要
Abstract
Since 2008,the number of seismic stations in Xizang area has increased significantly,and the earthquake monitoring capability has been significantly enhanced.However,the research on the minimum complete magnitude based on seismic events in different regions is still blank.Based on the earthquake events recorded by the Xizang Seismic Network,a total of 16 894 earthquakes with ML≥0.0 in Xizang area since 1970 were obtained after removing the aftershocks of significant earthquakes by K-K method.This paper calculates the time series of Mc in four regions,Northern Xizang area,western Xizang area,Lhasa and its surroundings,eastern Xizang area,using"magnitude-rank"method and the MACX method to investigate the temporal variation of Mc,and the spatial distribution characteristics of Mc are studied by using"complete magnitude range"method.The results show that the spatial and temporal distribution of Mc in Xizang area is not homogeneous in space-time,with most areas between ML 2.0-3.5 and a few areas between ML 1.0-2.0.Mc in Lhasa and its surrounding areas,western and eastern Xizang area is lower,which means the monitoring ability is higher,while Mc in northern Xizang area is higher,which means the monitoring ability is lower.The earthquake monitoring capabilities in the areas of Nagqu,Lhasa,Shannan to Shigatse,and south of Chamdo are the best,with a Mc of about ML 1.5.关键词
地震目录/最小完整性震级/时空特征/西藏Key words
earthquake catalog/minimum magnitude of completeness/temporal and spatial characteristics/Xizang area
