文章摘要

文章信息/Info

Title:: Research of OLR's Anomaly Before the Yushu and Jiuzhaigou Earthquakes

作者:: 杨星¹; 张铁宝¹; 陈锐²; 龙锋¹; 甘桂琴¹; (1.四川省地震局,四川成都 610000; 2.甘孜藏族自治州气象局,四川康定 626000)

Author(s):: YANG Xing¹; ZHANG Tiebao¹; CHEN Rui²; LONG Feng¹; GAN Guiqin¹; (1.Sichuan Earthquake Agency,Chengdu 610000,Sichuan,China)(2.Ganzi Meteorological Office,Kangding 626000,Sichuan,China)

摘要:: 利用风云三系卫星FY-3A和FY-3C的长波辐射产品,构建长波辐射背景场,计算玉树M_S7.1和九寨沟M7.0地震前后羌塘、巴颜喀拉、柴达木块体的距平变化及异常指数以期获得异常信息。结果表明:①玉树和九寨沟地震前都出现了OLR值的升高。②玉树震前,羌塘块体、巴颜喀拉块体异常指数最大分别为4.2倍、3.5倍标准差,异常指数回落后,地震发生; 九寨沟震前,羌塘、巴颜喀拉和柴达木块体在7月下旬的异常指数分别超过2.6,2.78和1.1倍标准差,异常指数下降后,地震发生。③2次地震前,距平和异常指数均存在异常,二者的变动或许和块体间和块体内部应力积累和卸载有关,也说明了震前长波辐射有记录区域异常现象的能力。

Abstract:: Based on the Outgoing Longwave Radiation products of FY-3A and FY-3C, the OLR's ambient field is constructed, and the anomaly index and departure of Qiangtang, Bayanhar and Qaidam blocks before and after Yushu M_S7.1 and Jiuzhaigou M7.0 earthquakes are calculated to obtain the anomaly information. The results show that:①OLR increases before Yushu and Jiuzhaigou earthquakes.②By calculating the anomaly indexes of the blocks of Bayanhar, Qaidam and Qiangtang, it's found that before the Yushu earthquake, the maximum anomaly indexes of the blocks of Qiangtang and Bayanhar were 4.2 times and 3.5 times of the standard deviation, respectively, then the earthquake occurred after the anomaly index's decrease; before the Jiuzhaigou earthquake, the anomaly indexes of the blocks of Qiangtang, Bayan Kala and Qaidam were more than 2.6, 2.78 and 1.1 times of the standard deviation, respectively. After the anomaly index drops, the earthquake occurs. ③Before the two earthquakes, there are anomalies in anomaly index and departure. The variation of them may be related to stress's accumulation and unloading between and within blocks, which also shows that OLR has the ability to record regional anomalies before earthquakes.