THREE-DIMENSIONAL CHARACTERIZATION OF A DEEP KARST AQUIFER BENEATH THE NORTH RIM OF THE GRAND CANYON

Karst aquifers are a major source of potable water for millions of people in northern Arizona. For Grand Canyon National Park (GRCA) and adjacent tribes, karst-fed springs serve as the major source of drinking water and support hundreds of endemic species. Previous studies on the north rim of the canyon show that annual snowpack on the Kaibab Plateau is an important driver for spring discharge. In addition, dye tracer studies indicate the presence of a complex network of fractures and conduits that can efficiently transport groundwater over large distances in timeframes of months to weeks. However, the flow paths snowmelt takes from the sinkholes on the plateau to the springs in the canyon are not well understood. These findings raise questions about the aquifer’s resilience to drought and susceptibility to contamination. To better delineate sensitive areas of recharge and predict flow regimes, we attempt to characterize hydrologic parameters from within the aquifer directly. In the Fall of 2022, over 10 km of hydrologically active cave passages were mapped using a mobile laser scanner. These data enable accurate extrapolation of joint sets, bedding planes and faults from the Redwall and Muav limestones within the Kaibab plateau. Preliminary findings illustrating how these features relate to regional geologic structures will be summarized. Lastly, these data will be showcased in an interactive format, which helps identify data gaps, indicate areas of interest for future research, and provide a powerful interpretive tool for visualizing complex karst systems.