基于HJ-1B卫星的玉树M_S7.1地震地表温度异常识别

Land surface temperature anomaly recognition of the Yushu M_S7.1 earthquake based on the HJ-1B satellite data

基于中国HJ-1B卫星热红外数据,对2010年玉树M_S7.1地震区进行地表温度(LST)研究。研究结果显示,2010年4月初LST异常值最初出现在毗邻震中的西南部,并且主要沿属于应力增强区的扎那曲-着晓断裂和杂多-上拉秀断裂分布;之后异常幅度逐渐增强,异常区域逐渐扩大至震中区域,但主要高值异常区依然位于震中西南部且沿着断裂带分布,显示出地表升温异常与断裂构造的相关性;在地表温度变化的过程中,4月14日发生了玉树M_S7.1地震,然后异常现象逐渐减弱,4月26日异常区域的LST值明显低于18日的数值并逐渐消散,5月中下旬该区域LST值恢复至正常状态;地震前后的LST异常呈出现-扩散集中-衰减-消失的变化过程。同时,以相同方法和标度计算了2009年同区域、同时段的LST值作为背景信息,进一步印证了2010年4月14日青海玉树M_S7.1地震LST临震异常的可靠性。

Land surface temperature（ LST） of the 2010 Yushu M_S7.1 earthquake is studied by using the Artis algorithm based on the HJ-1B satellite thermal infrared data,and the land surface temperature anomaly identification and test before and after the earthquake is completed. The results show that the initial LST anomaly appeared in the southwest of the epicenter on April 10,2010,and located along the main stress intensification areas,such as the Zanaqu-Zhoxog fault and Zadoi-Shanglaxiu fault. Then the abnormal area expanded gradually to the epicenter,but the mainly high anomaly area was still in the southwest of the epicenter and along the fault zone,which indicates the correlation between the faults and the LST anomaly. LST values of abnormal area on April 26 were significantly lower than the values on April 18 and gradually dissipated,and LST of this region returned to a normal state in late May. LST abnormity before and after the earthquake shows the anomaly change process of anomaly appearance- diffusion and concentration-decayingdisappearing. The pre- earthquake abnormity is evident. At the same time,this paper also calculates the LST results of the same period in 2009 of the same research area as the background information,which further confirms the reliability of LST anomalies as imminent earthquake precursors of the April 14,2010 Yushu earthquake,Qinghai.