Satellite thermal infrared remote sensing in geothermal prospecting in volcanic areas : A case study of the Xilingol volcanic field, Inner Mongolia, China
As the traditional energy source is in short supply and environmental problem is getting increasingly serious on the global scale,the development of new green energy has became a hot spot of the worldwide research. Compared to other alternative energies, geothermal is an inexpensive and stable energy source, and therefore has attracted great attention from general public and research community. It has a potential to play an important role in energy conservation and emissions reduction in the effort of tackling climate change. Geothermal energy is particularly rich in the Cenozoic volcanic areas where higher temperature can be expected at shallower depths, as compared to non-volcanic areas. Satellite thermal infrared (TIR) remote sensing has been proved to be effective in geothermal prospecting in volcanic areas in many countries, because it has the advantages of low cost, high efficiency and great spatial coverage over the traditional geological and geophysical exploration methods that are expensive and time consuming. However, satellite TIR remote sensing has not found much application in Chinese volcanic -geothermal research. This paper first presents a brief review of the history and current state of the technology, along with its applications in the Yellowstone National Park in U.S. and Aso volcanic area in Japan as two foreign examples, Changbaishan volcano in Jilin and Tengchong volcano in Yunnan as two domestic ones. The review is followed by a case study of the Xilingol Volcanic Field (XVF) with Landsat ETM+data. Seven areas of the XVF has been identified for next step geothermal investigation based on the analysis of the retrieved land surface temperature with a single channel algorithm and geological interpretation of bands 7-4-1 composite imagery as well as other supplementary information. This study shows that the major land surface temperature anomalies in the XVF are located in the intersections of the NEE- and NW-striking faults, and related to Cenozoic volcanic craters.