f Effect of mining subsidence on seismic velocity monitored by a repeated reflection profile

It is well known that longwall coal mining causes subsidence of the overlying rocks which extends up to the surface. The subsidence will be accompanied by a change in the stress regime above the workings, and one might anticipate that this will affect seismic velocities. In order to monitor any such changes, we have repeatedly surveyed a short seismic reflection profile in the Selby coalfield before, during and after minieg of a longwan panel.