2009年青海海西地震序列的潜热通量异常时空特征

 采用美国国家环境预报中心（NCEP）的地表潜热通量资料，对2009年8月28日青海海西6.4级地震及其余震前的潜热变化过程进行分析发现，① 主震前6d，震中附近开始出现潜热异常，然后异常幅度增强、面积扩大，并向震中迁移；② 余震前也出现了明显的潜热异常，但其时空演化过程不同于主震前的潜热异常；③ 潜热异常位置与震中具有良好的空间对应关系，其中都兰余震前的潜热异常位置与震中位置重合。本案例分析表明，震前地表潜热异常应是地震孕育尤其是临震过程的一种典型的岩石圈-盖层-大气耦合（LCA）效应，进一步的研究有望揭示特定地震区震前及余震序列的潜热通量异常规律，有益于地震监测预报研究与防灾减灾。

Spatial-temporal Features of Abnormal Surface Latent Heat Flux Before the Qinghai Haixi Earthquake Sequence in 2009

Remote sensing technology can be used to obtain accurately the variation of Surface Latent Heat Flux(SLHF), therefore, can serve as a means for long-term monitoring of SLHF for tectonic activities and earthquakes(EQ). In this paper, the SLHF data from NCEP are used to analyze the variation of latent heat before Qinghai Haixi Ms 6.4 earthquake on August 28, 2009 and its aftershocks. Several conclusions are drawn. (1) SLHF anomaly started to appear around the epicenter 6 days before the main shock. Then it continued to develop in intensity and extent, and moved to the coming epicenter. It disappeared when the main shock came. The maximum SLHF reaches 70W/m2. (2) SLHF anomaly also appeared before aftershocks, but in a different spatio-temporal evolving process. The evolving processes are multi-revolving with cycling features. (3) There is a good spatial corresponding relation between SLHF anomalies and the epicenters. The strong abnormal area corresponds to the main shock, while a weak abnormal area corresponds to aftershocks. Particularly, the SLHF anomaly is located exactly at the coming epicenter in Dulan aftershock. This case implies that SLHF anomaly before earthquakes should be a Lithosphere-Coversphere-Atmosphere (LCA) coupling effect in the earthquake preparation period, especially, in the impending-earthquake process. The features of SLHF anomaly before the main shock and aftershocks in seismic active regions might be important in future researches, and can be used in earthquake monitoring, prediction, hazard warning and disaster reduction.