安宁河-则木河断裂带闭锁与滑动分布动态变化

Dynamic Changes of Locking and Slip Distribution in the Anninghe-Zemuhe Fault Zone

利用2009~2011、2011~2013、2013~2015及2015~2018年4期GNSS水平速度场数据,基于块体与负位错模型,反演安宁河-则木河断裂带相应4个时期的闭锁程度和滑动亏损动态变化过程,结合GNSS速度场跨断层剖面分析结果,探究安宁河-则木河断裂带运动学特性动态变化。结果表明,安宁河-则木河断裂带闭锁分布呈周期性变化,但石棉-冕宁段始终处于高度闭锁状态;2013~2018年川滇块体相对于华南块体运动速率呈先减小后变大的变化趋势,该变化趋势对应则木河断裂带先闭锁后解锁的过程;根据跨断层GNSS速度剖面分析,安宁河-则木河断裂带运动特征呈分段变化。

Using GNSS horizontal velocity field data from 2009-2011,2011-2013,2013-2015 and 2015-2018,based on block and negative dislocation model,this paper inverts the dynamic change process of locking degree and slip deficit of the Anninghe-Zemuhe fault zone in corresponding four periods.We study the dynamic characteristics of the Anninghe-Zemuhe fault zone based on the GNSS velocity field across fault profiles.The results show that the locking distribution of the Anninghe-Zemuhe fault zone changes periodically,but the Shimian-Mianning section is always in a highly locked state.From 2013 to 2018,the movement rate of Sichuan-Yunnan block first decreased and then increased compared with the South China block,which corresponds to the locking and then unlocking process of the Zemuhe fault zone.According to the cross-fault GNSS velocity profile,the motion characteristics of the Anninghe-Zemuhe fault zone show sectional changes.