依兰—伊通断裂带地表温度变化分析

Variation of land surface temperature in Yilan--Yitong fault zone of northeastern China

GPS结果显示,2011年3月11日日本MW9.0大地震引起了我国东北地区的拉张活动增强,其中,依兰—伊通断裂带最显著.这个变化在温度场中是否也有所响应是一个值得探讨的问题,也是一个利用地表温度进行现今构造活动探索的机会.本文利用2000—2011年的中分辨率成像光谱仪(MODIS)地表温度产品对东北地区地表温度进行了分析,以去除稳定年周期变化的年变残差作为研究对象,通过空间和时间分析,排除地形、纬度、气象等干扰因素的影响,寻找与构造活动相关的热信息.结果表明,2001年初和2010年初依兰—伊通断裂北段曾经出现了显著的降温现象,且降温过程持续约两个月.通过气象资料分析,初步认为上述现象并非由气象因素引起.这与GPS远场同震位移结果所显示的依兰—伊通断裂带在日本地震后出现相对比较明显的张性应变相吻合.初步认为上述降温现象与依兰—伊通断裂的拉张增强有关.

GPS results show enhancement of tensile deformation in northeastern China, particularly in Yilan Yitong fault zone, due to the great Tohoku-oki, Japan, earthquake of 11 March 2011. The question of whether the earthquake had the same impact on land surface temperature or not deserves to be studied. In this study, land surface temperature variation in the Yilan-Yitong fault zone has been analyzed by using the land surface temperature product of moderateresolution imaging spectroradiometer （MODIS） research group from 2000 to 2011. After removing the stable annual variation component, the temperature residuals were analyzed. The purpose of this study is to find the thermal information related to tectonic activity by temporal and spatial analysis of land surface temperature observation with the influence of topography, latitude and other interferences being excluded. The result shows a significant continuous temperature decline for the two months at the beginning of 2001 and 2010 in the northern part of Yilan-Yitong fault. Meteorological factors are excluded by analyzing geo-temperature and rainfall data. Based on GPS studies, the Yilan- Yitong fault exhibited remarkable increase of tensile strain rate after the 2011 Tohoku oki earthquake in Japan, and the tensile strain would lead to temperature decline according to experiment result. Therefore, the phenomenon of temperature decrease is presumably caused by the tensile activity of the fault.