Correcting heat flow data in the United States to account for climate change

Heat flow measurements may require correction for both recent warming and post-glacial warming signals. Warming during the last century can be detected in borehole temperature profiles. Both climate warming signals during the past century and post-glacial warming signals during the past 10 millennia are greatest near the surface and diminish with depth.;Both atmospheric data and borehole temperature data show that recent warming varies systematically with latitude along a north-south transect in the United States. The systematic increase with latitude from +0.7 °C at 41.6°N to +2.3 °C at 49°N during the last century is consistent with the prediction that global warming due to increasing amount of CO 2 in the atmosphere varies with latitude.;A systematic increase of heat flow with depth is predicted to result from the post-glacial warming signal in the upper 2km. A modeled depth dependent correction of post-glacial warming indicated that the thermal gradient may be underestimated by 27% in some areas, thereby implying that some heat flow values in the United States may be up to 27% higher depending on the depth of the temperature gradient measurement. Averaging the corrected heat flow values shows that the average heat flow is 58 mW m-2, 78 mW m-2 and 51 mW m-2 for the whole conterminous United States, Western and Eastern United States respectively.