Study On Anomaly Of Remote Sensing Information And Mechanism Before The Wenchuan Earthquake

Earthquake monitoring and forecasting by means of remote sensing tools has become the forefront of seismic research and hot topic. Use MODIS data of satellite remote sense to extracte distribution of atmospheric water vapor and brightness temperature around the epicenter before and after the May 12, 2008 Wenchuan earthquake. To analyze the spatial-temporal distribution and the evolution and study the relationship between the spatial distribution and the fault structure. There is achieved the following results.Brightness temperature anomaly arises on the epicenter before the 12 d of the Wenchuan earthquake. But atmospheric water vapor anomaly arises on the epicenter before the 11 d of Wenchuan earthquake, about from 1.3 to 2.0 times. Brightness temperature anomaly occurred one day before the atmospheric water vapor anomaly. The change in trend between atmospheric water vapor and brightness temperature are consistent, so they must be relative.Atmospheric water vapor and brightness temperature anomaly are mainly controlled by the geological tectonic. Because the tectonic stress intensify, atmospheric water vapor and brightness temperature anomaly occurre along the fault and tectonic basin.With the study on the mechanism of remote sensing information anomaly occurred before the Wenchuan earthquake, it is considered that under the result of collision and extrusion of the Indian Plate and the Eurasian plate, deep materials of the western plateau flow and expand on the eastward, then enhanced stress and tectonic increased activity occurred near the epicenter. So the hot anomaly occurred. With the emergence of the hot anomaly, they make the earth's crust "red". The internal moisture vaporize and spill from the underground. The atmospheric water vapor anomaly occurred on the land surface.