Weingarten, Matthew听1听;听Ge, Shemin听2听;听Cutillo, Paula听3
1听University of Colorado
2听University of Colorado
3听National Park Service
Devils Hole, a fluid-filled cavern in the Amargosa Desert, southern Nevada, USA, is a fault-dissolution depression in carbonate rock, and is habitat for the only naturally occurring population of the endangered Devils Hole Pupfish,听Cyprinodon Diabolis. The pool lies at the intersection of several small aperture, northwest-trending, high-angle normal faults and a one-meter aperture, northeast-trending, high-angle reverse fault. In addition to being sensitive to solid earth tides and atmospheric pressure, the pool is highly sensitive to seismic sources, with continuous water level records from 1989 to the present recording hundreds of seismically induced water level oscillations. A catalog of seismically induced, high-frequency water level oscillations is presented. The pool鈥檚 sensitivity to seismically induced volumetric strains is on the order of 10^-11, which is three orders of magnitude less than the theoretical limit to coseismic strain sensitivity. Preliminary results suggest that the sensitivity of Devils Hole varies seasonally with seismically induced water level oscillations in the Fall averaging 50% larger volumes when compared to winter oscillations. In addition, frequency domain analyses of seismically induced water level oscillations utilizing 15-second frequency pressure transducer data from the past four years indicate response patterns in azimuthal direction, distance and magnitude of earthquake epicenters in relation to Devils Hole. The hypothesis that these patterns in seismic source sensitivity are directly related to the orientation of faults present at Devils Hole is tested.
Montgomery, D.R., and Manga, M., 2003, Streamflow and water well responses to earthquakes: Science, v. 300, p. 2047-2049.
Robertson, G., Ge, S., and Cutillo, P., 2007, An investigation of regional tectonic strain on water levels in Devils Hole: Journal of Geophysical Research, v. 34, L23308, 5 PP.