MEASURING THE ORGANIZATION OF A HIGHLY-DEVELOPED KARST AQUIFER: FIELDWORK IN THE MARTIN RIDGE CAVE SYSTEM, KENTUCKY

The original entrance to the Martin Ridge Cave System, Whigpistle Cave, was discovered in 1976 by Rick Schwartz, an employee of Mammoth Cave Hydrologist, Dr. James Quinlan. Over the next six years, explorers discovered and mapped extensive stream networks, kilometers of large trunk passageways, and the largest subterranean chamber in the Mammoth Cave region. Intermittent flooding and passage silting thwarted exploration efforts through the mid 1980s into the 1990s. Two additional entrances were discovered in 1994 and 1996. Survey from the new entrances allowed access beyond the flood-prone areas to numerous unexplored passageways. From these new entrances, over twenty additional kilometers of cave have been mapped. As of 2002, the Martin Ridge Cave System, 50 kilometers long, is the United States’ tenth longest cave.

Besides providing exciting opportunities for cave explorers, the Martin Ridge Cave System has yielded a great deal of information about the behavior and organization of its karst aquifer. Inaccessible in many karst watersheds, the Martin Ridge Cave System possesses a vast network of converging, dendritic subterranean streams. From the large set of field data, stream ordering and sinuousity values were calculated. The cave’s Travertine and Slackwater Creeks comprise an organized, fifth order stream network. Flow sinuousity for the cave streams yield a value of 1.5 (that is, an average stream in the cave flows a 150 meter path for every 100 meters of straight-line distance). Groundwater trace experiments show Martin Ridge to include a downstream portion of Mammoth Cave’s Hawkins River. Additional dye tracing, compared with overlying-surface elevation models, identified a location northwest of the Mill Hole Karst Window that appears to have had significant influence on the geomorphic history of the watershed.