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Title:: Present-day Activity of the Main Active Faults in Central Yunnan Area

作者:: 李长军¹; 2; 甘卫军^2; 秦姗兰¹; 郝明¹; 宋尚武¹; (1.中国地震局第二监测中心,陕西西安 710054; 2.中国地震局地质研究所,北京 100029)

Author(s):: LI Changjun¹; 2; GAN Weijun²; QIN Shanlan¹; HAO Ming¹; SONG Shangwu¹; (1.The Second Monitoring and Application Center,China Earthquake Administration,Xi'an 710054,Shaanxi,China)(2.Institute of Geology,China Earthquake Administration,Beijing 100029,China)

摘要:: 为研究滇中地区主要断层的活动特征,利用1999—2007年和2011—2017年2期GPS观测资料以及地质资料,基于Okada位错模型反演了研究区域主要断层的滑动速率和闭锁深度。结果表明:(1)红河断裂带的走滑速率为(1.5±1.6)～(4.7±1.5)mm/a,倾滑速率为(-3.6±1.6)～(1.9±2.4)mm/a,断裂南段的活动性更强;(2)无量山断裂和南华—楚雄—建水断裂的走滑速率为(4.0±1.6)～(5.6±1.5)mm/a 和(4.8±1.4)～(6.6±1.6)mm/a,倾滑速率分别为(-0.7±1.5)～(0.2±1.4)mm/a 和(-5.8±1.5)～(1.7±1.8)mm/a;(3)红河断裂带元江—元阳段和洱源—弥渡段、无量山断裂带和南华—楚雄—建水断裂带西段处于震间闭锁状态,闭锁深度分别为6.8 km,7 km和7.2 km。

Abstract:: To analyze characteristics of the main active faults in the central Yunan province,we inverted slip rates and lock depths of the main fault zones according to Okada's fault dislocation model based on GPS observations during 1999-2007,2011-2017 and geologic slip rates.Our results are as follows:(1)the strike-slip rate of the Red River fault is about(1.5±1.6)～(4.7±1.5)mm/a and the dip-slip rate is(-3.6±1.6)～(1.9±2.4)mm/a,while the southern segment is more active than other parts.(2)the strike-slip rates of the Nanhua-Chuxiong-Jianshui fault and the Wuliangshan fault are(4.8±1.4)～(6.6±1.6)mm/a and(4.0±1.6)～(5.6±1.5)mm/a,respectively.And the dip-slip rates are(-5.8±1.5)～(1.7±1.8)mm/a and(-0.7±1.5)～(0.2±1.4)mm/a,respectively.(3)the Yuanjiang-Yuanyang and Eryuan-Midu segments of the Red River fault,the Wuliangshan fault zone,and the western part of the Nanhua-Chuxiong-Jianshui fault are locked,with locking depths of 6.8 km,7 km,and 7.2 km,respectively.