Modeling Microgravity and DC-resistivity Response of a Longwall Mine at Soma-Darkale Coalfield

Abstract. Estimating the footprint of a coal panel becomes important to resolve conflicts related to the adverse effects of longwall coalmining. The conflicts may be about permit boundary infringement, mitigating subsidence-induced hazard, or in some cases, avoiding the old production fields while projecting a panel and panel orientations. The utility of gravity and dc-resistivity methods provide valuable information when evidence such as fracturing and/or pre-, and post-subsidence deformation profiles are insufficient. Coalmine subsidence increases the secondary porosities of the overlying strata, which causes water-level drop because of increasing storage, and reduces the densities of the overlying rocks. With this study, we develop a 3-D gravity modeling code to account for the factors that are likely affect the geophysical measurements. We also address the factors that are likely violating the fundamental assumptions of the dc-resistivity measurements obtained over a subsided production panel. The geophysical data used in this study were acquired over a longwall mine panel at Soma-Darkale Coal field.