A breakthrough has been achieved in carrying out identification, monitoring, estimation of ground temperature and depth of subsurface coal fires in Jharia coal field, Bihar, using remotely sensed imagery of Landsat TM6 and TM7 data. This is an important step towards understanding and identifying the phenomenon of coal fires and hazards posed by fires to coal mines and local residents.
Information on anomalous thermal pixels and geological structural setting has been collectively employed to estimate depth of subsurface coal fires. Thermal anomalies were used to pinpoint the pixels vertically above the existing fires. The visible and near infrared bands provide manifestations of coal ands on the surface. The least horizontal distance between the outcrop and the thermal anomaly can be measured. With the field information on the dip of the strata, the depth of the subsurface fire can be computed using simple planar geometry. It is inferred that subsurface coal fires ranges between 45-55 m, in most cases. A processed TM image of a part of Jharia coal field has been prepared, which serves as a quick reference image to view fire areas on the back ground relief of TM4 image.