【摘要】 利用川滇南部GPS站点速度资料,采用Kriging插值和有限单元中形函数(拉格朗日差值函数)求导原则,计算了川滇南部主应变速率.在此基础上,引入Kostrov地震矩率计算方法,由主应变速率求得了研究区的地震矩率,进而借助于Ward地震平均复发间隔公式计算了研究区地震(MS≥6.5)平均复发间隔.计算结果表明,川滇南部不同震级档地震复发间隔空间分布总体上与区内主要活动断裂展布基本吻合;地震复发间隔低值区主要分布在地震活动水平和滑动速率较高的安宁河—则木河—小江断裂带、丽江—小金河断裂西南段、红河断裂西北段.所得的结果与利用历史地震资料获得的结果基本一致.该方法对于历史地震资料缺乏或不完整地区和活动断层定量研究程度较低的地区有着潜在的应用价值.更多还原

【Abstract】 With a combination of the Kriging interpolation and shape function’s derivative (Lagrange interpolation function) used in finite element analysis,we have derived the elastic strain rate field in southern Sichuan-Yunnan region,China,based on the regional GPS velocity observations. Furthermore,the derived strain rate is directly converted into the seismic moment rate according to the Kostrov’s moment rate formula. By means of the Ward’s recurrence interval formula the recurrence intervals of MS≥6.5 earthquakes in southern Sichuan-Yunnan region are obtained numerically. The result shows that the contours of earthquake recurrence intervals generally coinside with the major fault zones. The low interval values are on the Anninghe-Zemuhe-Xiaojiang fault,the southwestern Lijiang-Xiaojinhe fault and the northwestern Red River fault,where the level of fault slip rate and earthquake activity is high. In general,the average earthquake recurrence intervals estimated in this paper are comparable with the intervals obtained from historical earthquake investigations. It should be pointed out that the methodology described in this paper has potential of application in modern seismic hazard assessment,especially for the regions being lack of instrumental and historical records.更多还原