National Cave and Karst Research Institute: Geophysics of a Doline Shaft System

Publication Abstract:

Memorial Athletic Field, State College, Pennsylvania was installed within an existing doline shaft system.  Although its early history included such uses as waste disposal and limestone mining, the Works Project Administration in the late 1930s converted the doline into Memorial Stadium.  Subsequently, a surface opening (throat) on the north side of the field was connected to a series of pipes that drain 20 hectares of street runoff.  A major issue with exploiting the throat for runoff disposal is that the void beneath grew over time due to erosion, dissolution, and subsidence.

The top of rock within the athletic field is roughly funnel-shaped and the interior of the “funnel” contains periglacial sediments as imaged through electrical imaging (EI) and microgravity (MG) mapping.  Profiles of the EI data using a forward modeling program show a well-developed void beneath the bleachers.  The microgravity data also show the presence of a north-south deep-rooted fracture system that probably opens to a larger series of voids at depths of greater than 20 meters.

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Geophysics of a Doline Shaft System