Updated Heat Flow Map of Alaska: Developing a Regional Scale Map for Exploration from Limited Data

Abstract

The 2015 update to the Heat Flow Map of Alaska (HFMAK) is described, focusing on the methodology of regional scale interpretation where direct geothermal measurements are sparse. The 2013 HFMAK had only 120 direct subsurface temperature measurements for gridding heat flow for the 1.718 million square kilometers of Alaska; furthermore, data were clustered in areas of petroleum exploration producing a data location bias. This methodology was constructed to combine geological and geophysical understanding and thermal data to interpolate heat flow between data points to define locations best suited for future research. Heat flow resolution is relatively high where there is sufficient data coverage (e.g. Copper River Basin and the Aleutian Volcanic Arc), whereas, map areas lacking detailed data coverage show the interpreted regional average heat flow. Heat flow is proposed to vary locally in map sections that are lacking data based on previous research in analogous geologic settings. The methodology presented here is best suited for constructing regional thermal maps for areas containing variable thermal data density with supplementary research in basement lithology, geophysics, and tectonic history.