祁连—海原地震带中强地震序列类型分布及其应用

摘要

The types of sequences and features of foreshock and aftershock activities of 18 MS≥5.0 earthquakes since 1970 along Qilian—Haiyuan seismic zone are studied.The space distribution of types of the sequences along the zone is analyzed.The results show that 44 percent of events are mainshock type,and 55 percent of events are isolated type.The sequences in Xiji—Haiyuan—Guyuan segment of the zone are isolated type,that in the middle-eastern segment of the zone are mainshock type,that in the middle segment of the zone are isolated type and mainshock type both, and that in the western segment of the zone are isolated type.The result of the seismicity trend judging after the Jingtai MS5.9 earthquake on June 6,2000 by using study results of this paper consists with real facts.%研究了1970年以来发生于祁连—海原地震带的18次中强地震序列特征，在此基础上确定了地震序列类型，研究了各种类型地震序列的分布规律．结果表明，该带的18次中强地震序列中有44%为主震型，56%为孤立型．西海固地区的中强地震序列一般为孤立型；101°～103.5°E范围内的祁连山中东段的中强地震序列一般为主震型；99°～101°E范围内的祁连山中段为孤立型和主震型序列并存；99°E以西的祁连山西段的中强地震序列为孤立型．将上述结果应用于2000年6月6日景泰MS5.9地震的震后趋势快速判定，判定结果与实际地震活动情况符合．