THE HYDROLOGIC RESPONSE OF A SHALLOW CAVE SYSTEM IN PENNSYLVANIA'S CUMBERLAND VALLEY

Cavers in south-central Pennsylvania have been frustrated for years by flood waters that often fill Cleversburg Sink Cave. Access to much of the cave system’s 3000-feet has been prevented by waters that appear to rise quickly, but recede slowly over a period of months. The source of the water has been unclear, as access requires climbing a slope from an ephemeral stream, then descending a funnel-shaped depression and spiraling down a passage to a breakdown room at the high water level. Water levels in the cave have never been related to the surface stream or local groundwater levels outside the cave. In October 2009 an In-Situ Troll 200 was placed in the cave to measure temperature, specific conductivity, and relative water level. National Speleological Society (NSS) cavers then surveyed from the transducer to the surface, and we continued a surface survey to a known bench mark and local hydrologic features. Preliminary results reveal an autumn water level that declines with a classic exponential decay function, but shows little- to-no response to some rain events.