卫星热红外异常——四川汶川Ms8.0级大地震的短临震兆

利用我国FY-2C红外一波段（10.3~11.3 μm）的卫星遥感图像,通过解译和研究,发现在5.12汶川大地震之前,就出现了明显、孤立的卫星热红外异常现象。其异常现象的特征具体表现为：①、震兆出现早：即在2008年3月18日（震前55天）,就开始出现了热红外异常;②、异常阶段多且复杂：汶川地震前的卫星热红外异常,可分5个阶段,而且热红外异常的展演各有不同。这在众多的卫星热红外地震研究案例中,可能是迄今为止异常阶段最多的一次;③、单个阶段的持续时间长：最长达13天;④、如此沿龙门山地震断裂带分布的明显的地热增温异常现象,可能在卫星热红外地震研究案例中是首次发现。这对研究发震特点、余震走向具有重要指示和启示意义。 本项研究的结果再一次证明：作为地震短临震兆,在地震（特别是≥Ms5.0）前必然出现热红外异常现象的实践性和规律性。利用卫星热红外异常现象进行地震短临预测研究是最有效和最有可能突破地震预测科学问题的途径和方法之一。     

尼泊尔8.1级地震卫星热红外异常解析

针对2015年4月25日尼泊尔8.1级地震前后在震中区附近出现的大范围热红外异常,以中国静止卫星FY-2C/E亮温资料为数据源,采用功率谱相对变化法进行数据处理和资料分析,结果表明:震前热异常具有显著的时空特征,异常范围呈不规则带状分布,且随时间推移逐渐扩大,至震时异常面积趋于峰值,震中始终位于异常区域的边缘部位,震后异常快速收缩减弱,直至完全消失。该次热异常变化表现为初步显现、加速发展至逐步衰减的过程,持续时间在45天以上,特征周期为16天,相对变化幅度达12倍多。通过相似震例对比研究发现,该次地震与汶川大地震的热红外时空演化特征存在一定共性,主要体现在热异常的演化过程、异常形态、发震时刻及震中位置与异常区域的关系上,仅特征周期和特征幅值有所不同,应与各区域应力变化、气候因素及特殊的地质环境相关。这些认识对热异常与地震三要素的关系判定有一定启示作用,对地震热红外监测预报工作具有重要意义。     

地震活动性热红外异常提取方法研究

热红外遥感以其大视野、高精度和短周期等诸多优势以及对某些强震红外异常的良好反映,成为监测断裂活动性及地震短临前兆的很有前途的观测技术。热红外异常与地震关系的研究也受到国内外地震学者的广泛关注。但由于地表热红外辐射受云层、地形地貌、地物类型和气象等诸多非震因素的影响,因此,如何从复杂的红外遥感数据中提取出与地震活动有关的热异常一直是这项研究中的瓶颈问题。在对若干震例和地震活动区的热红外影像进行长期分析研究的基础上,对这一问题进行了探讨,同时提出了一些实用化的异常识别与提取方法,并对其可行性进行了分析。认为地震红外异常是地表亮温的相对变化,判别地震异常时,至少需利用两年以上的卫星资料,从不同的时空尺度上加以综合对比分析,仅靠震前震后一定时段的卫星资料不足以排除所有非震因素的影响。     

卫星热红外地震短临预测方法研究

文章扼要介绍卫星热红外亮温异常的基本原理,分析建立地震短临预测遥感信息模型,通过11 a试验性预报实践和几个地震的案例,如南海东沙地震,台湾集集大地震,震例还有内蒙包头地震,美国华盛顿州奥林匹亚地震及印尼苏门答腊巨震等。从作为震兆的亮温异常提升到热应力场,对预测地震震中更加可靠和更有说服力,说明此项技术具有实际应用前景。     

2010年新西兰M7.1地震前的长波辐射变化特征

以2001—2011年美国NOAA长波辐射数据为背景数据,利用涡度背景场法研究2010年9月3日新西兰南岛M7.1级地震前后卫星长波辐射数据变化特征。结果表明,地震当月在震中西南侧出现显著的长波辐射异常变化,这种变化在全年各月及2001—2011年11年历年同月变化中都是最为显著的,认为其是本次地震的1次映震表现。用同样方法对区内2001—2011年11年间发生6次7.0级以上地震的长波辐射数据进行分析,结果在3次陆地地震发震前都检测到了长波辐射异常变化,而海域地震前则未发现这种现象。检索前人的相关研究结果,发现仅有2次海域地震(2004年12月26日印度尼西亚苏门答腊西北海域8.7级地震和2010年1月12日海地7.0级地震)前有长波辐射异常变化的报道,而根据全球云量分布资料显示,这2个地震所发生的区域是全球洋面云量分布最少的2个区域,而新西兰地震发生的区域位于全球洋面云量分布最多的区域。因此,认为由于水汽和云层对地表红外辐射的强吸收作用,长波辐射捕捉陆地地震红外辐射异常变化更加灵敏,对陆地地震的映震效能要强于海洋地震。     

川滇块体中强震前热红外辐射异常研究

中强震频发的川滇块体是研究地震前兆信息的热点地区,中强震前存在热辐射异常已被很多震例证实,有必要对川滇块体中强震前的热辐射异常进行系统研究总结,为该地区热辐射的研究应用提供一定的参考。本文以多年MODIS/Terra卫星热红外亮温数据为基础,对2004年4月至2014年8月川滇块体5级以上地震前的热红外亮温低频信息进行了分析。结果表明:(1)川滇块体M≤6.1级的地震震前观测不到大范围的显著热辐射增强异常,这可为该地区大范围显著热辐射增强异常出现后地震震级预测提供一定的参考依据;(2)2014年8月3日鲁甸M6.5级地震前川滇块体存在大面积显著热辐射增强异常,这类异常对该地区6.5级左右的地震具有短期指示意义。     

地震前卫星红外异常特征分析

通过对1999年以来发生在中国的几个强地震前的卫星热红外异常分析,得出认识:地震前增温异常具有时间上的突发性、形态上的孤立性、分布上的局限性、异常昼夜对比具有稳定性、异常位置具有迁移性和演变规律具有阶段性;不同构造区强地震前的卫星红外异常分布不同,沿海平原区表现为大范围的面状分布,而山区则以带状延伸为主;在强烈活动的断裂带,异常分布表现为与构造的密切相关性,断裂带内外亮温差分析法定量分析红外增温与活动断裂的时空关系,是提取震前增温异常的有效方法.活动断裂是红外异常反应的最敏感地带.在断裂变形的不同阶段,断裂带内外的卫星红外亮温关系是有差异的.在断裂活动的正常时期,断裂带内外亮温差在某一范围内波动,而在断裂活动的异常时期,断裂带内外亮温差变化到一个新的水平,断裂带内的增温将大于断裂带外的增温.2001年昆仑山8.1级地震和2000年云南姚安6.5级地震都是如此.利用发震断裂带内外亮温的相对变化提取异常信息,在大多数情况下可以消除地形和云层的影响.     

应用MODIS卫星遥感资料进行地震预测的初步研究

利用MODIS卫星遥感资料的亮温异常变化信息应用于地震预测研究,虽然目前还处于探索研究阶段,但根据该资料在台湾地区几次中强地震前的异常信息分析认为,其亮温异常信息可作为台湾地区中强地震前的一种较可靠、有效的短临预测方法。其基本原理是构造块体在破裂或错动前,因地壳岩石受挤压时应力应变的增强而引起了震源区及其周边区域的异常增温现象。     

永安西南5.1级地震前尤溪电磁辐射异常特征的研究

本文通过研究1997年5月31日永安西南M_L=5.1级地震前尤溪电磁辐射异常特征及其与本次地震三要素的关系,探讨利用数字采集仪PP40打印机记录电磁辐射信息,比起模拟记录的优势所在,总结出利用震前电磁辐射异常信息,进行短临地震预报的一些规律。     

基于红外遥感资料的断层活动变化特征研究——以岷县—漳县6.6级地震为例

正断层活动与地表热环境紧密相关,同时发挥着把热异常和地震联系起来的承载作用。大多数强烈地震前都存在突出的热红外异常现象(徐秀登等,1991;陈梅花等,2003;邓志辉等,2003;康春丽等,2003),且可以利用有效的提取方法进行判定和识别(张元生等,2011;荆凤等,2013;张璇等,2013;郭晓等,2013)。地震热红外异常形态在震中区大多表现出与发震断裂走向基本一致的特征,     

Satellite Thermal Infrared Earthquake Precursor to the Wenchuan Ms 8.0 Earthquake in Sichuan, China, and its Analysis on Geo-dynamics

Based on an interpretation and study of the satellite remote-sensing images of FY-2C thermal infrared 1st wave band (10.3-11.3 μm) designed in China, the authors found that there existed obvious and isolated satellite thermal infrared anomalies before the 5.12 Wenchuan Ms 8.0 Earthquake. These anomalies had the following characteristics: (1) The precursor appeared rather early: on March 18, 2008, I.e., 55 days before the earthquake, thermal infrared anomalies began to occur; (2) The anomalies experienced quite many and complex evolutionary stages: the satellite thermal infrared anomalies might be divided into five stages, whose manifestations were somewhat different from each other. The existence of so many anomaly stages was probably observed for the first time in numerous cases of satellite thermal infrared research on earthquakes; (3) Each stage lasted quite a long time, with the longest one spanning 13 days; (4) An evident geothermal anomaly gradient was distributed along the Longmen seismic fracture zone, and such a phenomenon might also be discovered for the first time in satellite thermal infrared earthquake research. This discovery is therefore of great guiding and instructive significance in the study of the earthquake occurrence itself and the trend of the post-earthquake phenomena.     

Satellite Thermal Infrared Earthquake Precursor to the Wenchuan Ms 8.0 Earthquake in Sichuan,China, and its Analysis on Geo‐dynamics

Abstract: Based on an interpretation and study of the satellite remote-sensing images of FY-2C thermal infrared 1st wave band (10.3–11.3 μm) designed in China, the authors found that there existed obvious and isolated satellite thermal infrared anomalies before the 5.12 Wenchuan Ms 8.0 Earthquake. These anomalies had the following characteristics: (1) The precursor appeared rather early: on March 18, 2008, i.e., 55 days before the earthquake, thermal infrared anomalies began to occur; (2) The anomalies experienced quite many and complex evolutionary stages: the satellite thermal infrared anomalies might be divided into five stages, whose manifestations were somewhat different from each other. The existence of so many anomaly stages was probably observed for the first time in numerous cases of satellite thermal infrared research on earthquakes; (3) Each stage lasted quite a long time, with the longest one spanning 13 days; (4) An evident geothermal anomaly gradient was distributed along the Longmen seismic fracture zone, and such a phenomenon might also be discovered for the first time in satellite thermal infrared earthquake research. This discovery is therefore of great guiding and instructive significance in the study of the earthquake occurrence itself and the trend of the post-earthquake phenomena.     

大地震临震预测的研究进展

短临地震预报尤其是临震预报 ,是当今国内外公认的世界性科学难点。文章综述了中国科学家从多学科交叉和内外因耦合的科学途径 ,已在大地震临震信号方面获得了次声波异常、地应力突跳、虎皮鹦鹉跳跃异常、地电和地磁异常、卫星红外异常、重力高频脉冲等临震预测的手段。笔者通过典型分析和普查对比各种地球物理因子和各种天文因子可能影响的整体研究 ,找到了大地震临震的主要触发因子———以月亮为主的非经典引潮力共振的异常叠加。在此基础上 ,采取内外因耦合的途径和方法 ,在 6a多来联合进行的临震预测内部试验表明 ,地震三要素均基本正确的成功率已达40 %。最后 ,还对临震预报问题提出了一些看法。     

Satellite detection of earthquake thermal infrared precursors in Iran

Stress accumulated in rocks in tectonically active areas may manifest itself as electromagnetic radiation emission and temperature variation through a process of energy transformation. Land surface temperature (LST) changes before an impending earthquake can be detected with thermal infrared (TIR) sensors such as NOAA-AVHRR, Terra/Aqua-MODIS, etc. TIR anomalies produced by 10 recent earthquakes in Iran during the period of Jun 2002–Jun 2006 in the tectonically active belt have been studied using pre- and post-earthquake NOAA-AVHRR datasets. Data analysis revealed a transient TIR rise in LST ranging 2–13°C in and around epicentral areas. The thermal anomalies started developing about 1–10 days prior to the main event depending upon the magnitude and focal depth, and disappeared after the main shock. In the case of moderate earthquakes (<6 magnitude) a dual thermal peak instead of the single rise has been observed. This may lead us to understand that perhaps pre-event sporadic release of energy from stressed rocks leads to a reduction in magnitude of the main shock. This TIR temperature increment prior to an impending earthquake can be attributed to degassing from rocks under stress or to p-hole activation in the stressed rock volume and their further recombination at the rock–air interface. A precise correlation of LST maps of Bam and Zarand with InSAR-generated deformation maps also provides evidence that the thermal anomaly is a ground-related phenomenon, not an atmospheric one.     

Crustal geodynamic activity: manifestations in cloud fields

We consider different kinds of linear cloud anomalies appearing in satellite images over active crustal faults. The spatiotemporal relationship between earthquakes and cloud anomalies was studied by statistical methods. It has been shown that these cloud anomalies in the atmosphere can be used for short-term prediction of the earthquake time and region. Also, we consider the earthquake-related evolution of the giant thunderstorm cloud near the epicenter before the earthquake.     

Machine learning-based thermal anomalies detection from MODIS LST associated with the Mw 7.7 Awaran,Pakistan earthquake

Natural Hazards - Satellite based thermal anomaly occurs as a substantial precursor for strong earthquakes, as the need for earthquake precursor detection has very important for impending main...     

Satellite detection of thermal precursors of Yamnotri,Ravar and Dalbandin earthquakes

Prior to the occurrence of an earthquake, the region undergoes intensive physiochemical changes. Such changes trigger degassing charge generation leading to positive change in the thermal regime and consequently creation of an earthquake preparation zone. These changes in thermal regime can be detected by the thermal sensors onboard various polar orbiting satellites. Recent researches have demonstrated that thermal infrared sensors onboard satellites (e.g., NOAA-AVHRR and Terra/Aqua-MODIS) can detect temporal transient thermal infrared anomalies prior to an earthquake. The paper presents satellite-based thermal observations associated with Yamnotri (July 22, 2007, India), Ravar (October 14, 2004, Iran) and Dalbandin (January 19, 2011, Pakistan) earthquakes. In the case of Yamnotri earthquake, the region attained around 5–8°C higher than the normal temperature on July 21, 2007 in the area, just 1 day before the earthquake. Whereas, in the case of Ravar earthquake, the region has shown 5–7°C higher temperature on October 06, 2004 about 6 days before the occurrence of the main earthquake event. Dalbandin earthquake showed a maxima on January 17, 2011, just 2 days before the main shock with the raised temperature of around 8–10°C. Another common observation in all these earthquakes is the disappearance of short-term transient thermal anomaly just before the main shock.     

云南地区水温异常与地震关系

云南地区地震频发, 水温观测点分布也最集中, 为研究水温异常与地震的关系提供了便利条件.通过收集已经公开发表关于该区域"十五"之前的水温异常与地震的对应关系的文章, 较系统地研究了水温异常持续时间、异常空间位置与地震之间的关系.结果表明: 水温异常主要是地震短临异常, 强震前也存在水温中期趋势异常; 一般情况下, 地震震级越大, 异常范围越广, 发震地点通常出现在水温异常集中的区域.      

吉林地区地电阻率震兆异常对比分析

对采用形态法、归一化变化速率法和各向异性度法提取到的吉林省内深源地震以及浅源地震前的地电阻率异常变化进行对比分析,结果表明:(1)震前地电阻率出现1~2年尺度中期异常,甚至短期异常,异常以负异常为主;(2)震前地电阻率原始月均值异常变化幅度1%,表明数字地电仪捕捉电信号灵敏度的提高,更与台址构造密不可分;(3)震前地电阻率出现异常变化,震后恢复到正常变化形态,反映出震前震中区地下应力的变化,震后区域构造应力场重新调整并逐渐恢复的过程。