Date of Award
Beverly Karplus Hartline
Temperature and pressure were measured in several flooded underground mine shafts in order to assess the potential for the development of additional mine-based geothermal heating in Butte, Montana, USA. Temperature was sensed using both optical fibers, functioning as a distributed sensor, and thermistors, functioning as point sensors; while pressure was sensed using a piezoresistive strain gauge. Upon observing good agreement between the continuous and discrete temperature sensors, we found no significant change in temperature with increasing depth within the water column. This suggests the thorough transfer of heat throughout the mine shaft via convection. Moreover, we found water temperature (T) is directly proportional to total mine shaft depth (z) via the equation: T = 0.0225*z + 3.0194, where T is in degrees Celsius and z is in meters – demonstrating an observed geothermal gradient of 22.5 ˚C per km.
Hagan, Tyler, "Temperature and Pressure Sensing in Three Flooded Underground Mine Workings in Butte, Montana, USA" (2015). Graduate Theses & Non-Theses. 21.