High-resolution temperature monitoring in Devils Hole

Authors: Mark B. Hausner, Scott W. Tyler, Kevin P. Wilson, Michael R. Bower

Year: 2009 (xli)

Abstract

Devils Hole is a window into the carbonate groundwater that is located in the Amargosa Valley of southwestern Nevada, and is the sole habitat for the endangered Devils Hole pupfish, Cyprinodon diabolis. Temperatures within Devils Hole are at the upper physiological threshold for aquatic organisms, consistently at 33.5°C. However, temperatures on the small (2.6 x 6.1 m) shallow shelf can be higher during summer months (approaching 37.0°C) and lower (approaching 26.0°C) during winter. Higher summer temperatures have a negative impact on pupfish life history and productivity of lower trophic levels such as macroinvertebrates and algae. A fiber-optic distributed temperature sensor (DTS) was used to continuously measure temperatures over 3-5 days during different times of the year. Vertical temperature profiles and spatially scattered temperatures on the shallow shelf are presented, and future planned DTS deployments are described. The collected temperature data will form the basis for a hydrodynamic model of the thermal regime of Devils Hole. This computational fluid dynamic model will consider geothermal heating and conduction, latent heat flux, sensible heat flux, short-wave and long-wave radiation, as well as thermally driven convection, and is intended to examine both seasonal and long-term changes in the thermal regime of Devils Hole.