The high-temperature thermal abnormal areas are found on TM6 imageof Aug.28th in 1987 in the interested region of Longdong loess plateau

These ar-eas are accompanied by lowtemperature thermal abnormal areas.But on TM6 ima-ges of Sept.1987 and Aug

1986

the features of thermal infrared are in accordancewith normal thermal infrared radiation rules

there are no abnormal phenomena.To make out the causes of thermal abnormality

we find out that there happe-ned an earthquake of 5.1 magnitude in northwest of the interested region on Aug.10th in 1987 and existed oilfields and oilwells are mostly located inside low temp-erature thermal abnormal areas along the edges of the high-temperature thermal abn-ormal areas.These two factors are main causes of TM6 image abnormality of Aug

28th.The earthquake enhances the thermal radiation of geological body and leads tothe high-temperature thermal abnormality and a lot of effusion of hydrocarbon ma-terials.These bring about the reformation of related

composition and augmentationof moisture in the soil

and finally the lower abnormality in oilfield is formed.Itis evident that the lower abnormal area is one of the most important marks for pre-diction oil gas reserve.