ELECTROMAGNETIC AND SEISMIC INVESTIGATION OF ABANDONED MINE TUNNELS AT WALLY ROSE FIELD

Abandoned mine tunnels are found within the Pittsburgh area as well throughout Pennsylvania. Many areas around Pittsburgh have been undermined to excavate coal that helped heat homes in the 1800s and 1900s. Areas such as Brookline, Mount Washington, Allentown and Mt. Oliver have been undermined for their coal resources. Mining companies who operated at those times ceased operation after the resources were depleted and little to no historical documentation of the mine tunnels exist. Abandoned mine tunnels have the potential to collapse due to overburden, which may give rise to structural damage to homes and businesses. To help aid or prevent against this impact it is beneficial to develop non-intrusive methods to assist in the location of abandoned mine tunnels.

Based upon historical documents, abandoned mine tunnels are known to exist beneath Wally Rose field, a site located on the campus of Slippery Rock University. An active source surface wave seismic survey was performed at Wally Rose field resulting in a shear wave velocity profile of the subsurface. The shear wave profile identified several geophysical anomalies that are at the expected depth and locations of the abandoned mine tunnels.

To gain additional understanding of the electromagnetic properties of the subsurface and to further investigate the geophysical anomalies identified by the seismic survey, an electromagnetic survey was undertaken at Wally Rose field. The survey was conducted using a multi-coil electromagnetic conductivity meter that allows for simultaneous, multi-depth data acquisition. Electromagnetic data were acquired across the entirety of Wally Rose field and the results indicate higher conductivity anomalies at the expected depth and location of the tunnels when compared to data acquired over areas of the survey where abandoned mine tunnels are not expected to exist.