Geophysics Applied To Abandoned Mined Land

The evaluation of Abandoned Mined Lands can involve the investigation of very large areas of land. Often, the locations of critical areas or impending problems are unknown, and are not easily identified from the surface. Microseismic monitoring has been demonstrated to be effective in identifying potential instabilities and active movement in mines from distances of several kilometers. By placing sensors in proximity to, or in contact with, a high acoustic conductance layer close to the mined zone, large areas can be monitored for potential problems with a minimum of sensors and drillholes. As part of a U.S. Bureau of Mines contract, a prototype system was developed to identify and locate potential instability problems over wide areas of land. Once a problem area has been located, the system can be used to analyze the type of the problem, its size, relative degree of instability, and potential for damage. Continued monitoring after application of remedial measures can effectively determine the efficacy of those measures.