Measured versus simulated transients of temperature logs - A test of borehole climatology

Abstract

We report the results of repeated temperature, T, measurements with depth (z) for two borehole sites located in the Western Canadian Sedimentary Basin, in central Alberta and south central Saskatchewan. These were logged at three different times within the time period of 1986 AD to 2004 AD. Subsurface temperature transient changes of 0.1 to 0.4 °C observed between the repeated temperature logs over the last two decades agree only partially with the changes derived from the synthetic profiles in which surface temperature time series were used as forcing signals. The surface temperature forcing is responsible for the majority of the observed deviation of temperature with depth. In some cases, differences higher than the error of measurement are observed between the model and measurements. This can be an indication that factors other than the surface temperature change also influence the subsurface thermal regime. © 2005 Nanjing Institute of Geophysical Prospecting.