The Geothermal Map of North America is a heat flow map depicting the natural heat loss from the interior of Earth to the surface. Calculation of the heat flow values requires knowledge of both the temperature gradient at a location and the thermal properties of the rocks in which the gradient is measured.
The first Geothermal Map of North America was prepared by Dr. Dave Blackwell and John Steele in late 1980’s and published in 1992 by the Geological Society of America (GSA) in conjunction with the GSA sponsored Decade of North American Geology.
Dr. Blackwell, working with Geothermal Lab staff and graduate students, prepared an updated version of the Geothermal Map of North America which was published by the American Association of Petroleum Geologists (AAPG) in 2004. Citation: Blackwell, D.D., and M. Richards, Geothermal Map of North America, AAPG Map, scale 1:6,500,000, Product Code 423, 2004.
Supported by Google.org, the SMU Geothermal Laboratory and Dr. Blackwell completed a third generation heat flow map of the continental U.S. in 2011. Citation: Blackwell, David, M. Richards, Z. Frone, J. Batir, A. Ruzo, R. Dingwall, and M. Williams 2011, Temperature at depth maps for the conterminous US and geothermal resource estimates, Geothermal Resources Council Transactions, 35, 1545-1550. GRC Record 1029452.
Data used to generate these maps are available in the National Geothermal Data System (NGDS).