Correcting Heat Flow Data in the United States to Account for Climate Change
Godswill O. Njoku
University of North Dakota, Harold Hamm School of Geology and Geological Engineering
Heat flow measurements require correction for both recent warming and post- glacial warming signals. Over the last century there has been an increase in warming trends due to climate change in borehole temperature profiles with post-glacial warming signal greatest near the surface and diminishes with depth.
Recent warming signals was detected within climatic zones along a north-south transect in the United States which vary systematically with latitude. Furthermore, it was determined that warming signals increased systematically with latitude from +0.7oC at 41.6oN to +2.3oC at 49oN during the last century and these conform with the prediction that global warming due to increasing amount of CO2 in the atmosphere varies with latitude.
The systematic increase of heat flow variation with depth is predicted to be a result of the effect of post-glacial warming affecting the temperature gradient of the upper 2km. The modeled depth dependent correction of post-glacial warming resulted in the underestimation of the thermal gradient measurements by 27%, thereby, implying that the heat flow values in the United States are 27% higher depending on the depth of the temperature gradient measurement. Averaging the corrected heat flow values shows that the average heat flow is 74 mW m-2, 78 mW m-2 and 51 mW m-2 for the whole conterminous United States, Western and Eastern United States respectively.
AAPG Search and Discovery Article #90182©2013 AAPG/SEG Student Expo, Houston, Texas, September 16-17, 2013