利用遥感技术研究断层现今活动的探索——以玛尼地震前后断层相互作用为例

AN ATTEMPT TO STUDY FAULT ACTIVITY USING REMOTE SENSING TECHNOLOGY—A CASE OF THE MANI EARTHQUAKE

在前人工作的基础上 ,提出了利用遥感技术探测活动断层现今活动的新思路。以1997年玛尼 7.9级地震为例 ,研究了地震前后震中周围地区地温图像的动态演化。研究证实在玛尼地震前 2 0d阿尔金断裂带的东段就开始出现增温现象 ,然后逐渐扩展 ,形成了明显的条带。这条带一直持续到 11月 8日玛尼强震的发生。地震后此增温异常条带逐渐消逝。而引发玛尼地震的玛尔盖茶卡断层在震前 2d才开始出现增温异常。图像的变化过程显示 ,玛尼地震与阿尔金断裂带活动的明显增强过程之间有着一定的对应关系 ,说明两断层间存在相互作用以及变形异常—断层现今活动—地震三者间有密切关系。此外 ,还针对深入研究断层现今活动及断层相互作用的需求 。

On the basis of previous studies of other researchers, we propose a new approach to detect present day activities of faults using remote sensing. We have studied the dynamic changes of ground temperature around the epicenter before and after the Mani M S7.9 earthquake of 1997. It is found that an anomalous increase of ground temperature occurred at the east section of the of Altyn Tagh fault 20 days before the event. Then this anomalous area expanded gradually, formed a remarkable belt which remained till the occurrence of the M S7.9 earthquake. After the event this belt of anomaly was fading away, while such an anomaly appeared on the seismogenic fault—the Margaichace fault as late as two days before the Mani M S7.9 event. The evolution process of the image shows that there is some corresponding relationship between the Mani earthquake and evident activity of the Altyn Tagh fault. It also indicates the interaction between the two faults mentioned above as well as the close relation among the deformation anomaly, present day fault activity and earthquakes. In addition, we propose improvement of the technique for the requirement of the study on present day activity and interaction of faults.