摘要
以2000年以来6.4级以上地震为例,研究了腾冲地区潜热通量(SLHF)在这些震例发生前后的变化特征。结果表明:腾冲地区的SLHF动态,不但在其附近发生强地震前常出现异常,而且对周边较远的强地震前也会发生异常反应;异常出现时间大都在震前1个半月以内,汶川地震前异常出现较早,发生在震前2个月之前,这可能与汶川地震震级高影响范围大有关;异常幅值与震级有关,震级越大,异常表现越强。比如芦山7.0级地震、缅甸7.0级地震和汶川MS8.0地震前,腾冲地区SLHF异常幅度很大,远远超过最大参考值,而姚安6.5级地震和宁洱6.4级地震前异常幅度就相对小一些。腾冲地区SLHF异常与周围强地震的发生有较好的相关性,一方面与腾冲地区的活动断裂发育、现今构造变形强烈有关,另一方面可能是由于腾冲地区火山活动强烈,温泉广泛发育,水热交换迅速,对周边构造活动感应灵敏所致。
Domestic and foreign scholars found that SLHF anomaly occurred before some strong earthquakes in coastal area or in inland region with abundant water. The author noted that SLHF anomaly in some special tectonic position is not only associated with the strong earthquakes nearby but also with the strong earthquakes far away in the same tectonic belt. The dynamic variation rule of SLHF anomaly in the special tectonic position prior to earthquakes might reveal some trend of regional seismic activity and contribute to the research of mechanism of SLHF anomaly prior to earthquakes. Tengchong area in Yunnan Province is such a special tectonic position located in the south of the eastern Himalayan syntaxis and is one of the youngest volcanic regions on the Chinese mainland with frequent magmatic activity and strong hydrothermal activity. The earthquakes （Ms ≥ 6.4） since 2000 in Sichuan-Yunnan region （including the Yao＇an Ms6.5 earthquake in 2000, the Ning＇er Ms6.4 earthquake in 2007, the Wenchuan Ms 8.0 earthquake in 2008, the Ms7.0 Myanmar earthquake in 2011 and the Lushan Ms7.0 earthquake in 2013）are selected as cases to study the variation characteristics of the SLHF in Tengchong region before and after the above earthquakes. It is found that significant SLHF anomalies occurred in Tengehong area not only before earthquakes happening in the vicinity but also earthquakes far away in the surroundings. The SLHF anomalies occurred mostly within one and half months before the earthquakes, except Wenchuan Ms 8.0 earthquake. The SLHF anomalies occurred two months before Wenchuan earthquake, the earlier occurrence of the anomalies might be due to the relatively long distance between Wenchuan earthquake and Tengchong area. It is also found that the amplitude of anomaly is related to earthquake magnitude, the larger the magnitude of earthquake, the larger the amplitude of the anomalies. For example, the SLHF anomalies in Tengchong region prior to Burma Ms 7 earthquake and Wenchuan Ms 8.0 earthquake are very stron
出处
《地震地质》
EI
CSCD
北大核心
2014年第2期422-433,共12页
Seismology and Geology
基金
中国地震局地质研究所基本科研业务专项(IGCEA1124)
国家自然科学基金(40702056
40841016
40372131)共同资助
关键词
地震异常
潜热通量
异常相关性
腾冲火山
遥感
earthquake thermal anomaly, surface latent heat flux, association between SLHFanomaly and earthquakes, Tengchong volcano, remote sensing
