Microwave Radiometric Investigations of Mine Subsidence in Rock Springs,Wyoming.

摘要

The investigations were performed in two areas where mapping techniques are needed for locating abandoned coal mines and subsidence-prone areas. Microwave surveys were conducted specifically to map the overburden moisture distribution resulting from the subsurface geology. The microwave radiometric maps and supporting data were analyzed in terms of both surface and subsurface phenomena,and were compared with the available subsurface information. Data from the 21cm showed better response to subsurface conditions and were used for all detailed sensor analyses. Preferential distribution of near-surface moisture was observed on both sites. A major subsurface feature was located that extended more than 750feet. This feature exhibited a positive microwave signature that correlates closely with a large haulage tunnel in the No. 7coal seam,which occurs at a depth of 160feet. At this location there is no surface evidence of subsidence and the anomaly is believed to be associated with active subsidence which has not reached the surface. Several other anomalies were attributed to factors unrelated to mining activities or subsidence. (Author)