HR: 1020h
AN: PP52A-0658    [Abstracts]
TI: When is groundwater flow an important consideration in ground surface temperature reconstructions?
AU: * Ferguson, G
EM: gferguso@stfx.ca
AF: St. Francis Xavier University Department of Earth Sciences, Box 5000, Antigonish, NS B2G 2W5 Canada
AU: Woodbury, A D
EM: woodbur@cc.umanitoba.ca
AF: University of Manitoba Department of Civil Engineering, 246C Engineering Bldg 15 Gillson St, Winnipeg, MB R3T 5V6 Canada
AU: Beltrami, H
EM: hugo@stfx.ca
AF: St. Francis Xavier University Environmental Sciences Research Centre, Box 5000, Antigonish, NS B2G 2W5 Canada
AB: The utility of subsurface temperatures in paleoclimate studies has become well established in recent years. However, there are many different factors that could cause questioning of the result of ground surface temperature (GST) reconstructions from temperature measured in boreholes. One of these factors is groundwater flow, particularly downward groundwater flow. In this case, the resulting curvature in the temperature profile is similar to that observed in many conductive environments where GST has increased over the past century. Simulations of heat flow with steady-state groundwater flow and constant GST indicate that groundwater flow will only significantly affect groundwater reconstructions when Peclet numbers are greater than 0.1 to 1.0. This generally occurs in areas with moderately high recharge rates. Here we show how meteorological records and information on permeability of the rocks and soils in the vicinity of a borehole can be used boreholes in areas where advection will have a minimal effect on GST reconstructions.
DE: 1878 Water/energy interactions (0495)
DE: 4914 Continental climate records
DE: 8130 Heat generation and transport
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005