Records of climatic change in the Canadian Arctic: towards calibrating oxygen isotope data with geothermal data

Borehole temperature-depth data have been combined with oxygen isotope data from an ice core at a nearby location in the Canadian Arctic to calibrate the oxygen isotope data to ground temperature histories. The relationship of oxygen isotope data to ground surface temperature history is δ18O = 0.42ΔTg and this reproduces the main features of the observed subsurface temperature profile measured at the borehole site. These results suggests that oxygen isotope data are a good representation of the regional, long term climatic variations at these latitudes. Discrepancies between the observed subsurface profile and the theoretical profile calculated from the calibrated oxygen isotope time series may be explained in terms of the different character of the records, in particular snow cover, and active layer processes.