Earth's surface heat flux

• Main Authors: Davies, J, Davies, Rhodri
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Copernicus GmbH
• Subjects: Keywords: Antarctica; Data sets; Earth's surface; Geographical information; Geologic domains; Global estimate; Half-space; Hotspots; Hydrothermal circulation; Oceanic crust; Oceanic lithosphere; Estimation; Geographic information systems; Geology; Heat transfer; He; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/1885/65286; https://openresearch-repository.anu.edu.au/bitstream/1885/65286/5/Davies_DR_2010_Earth%2527s_surface.pdf.jpg; https://openresearch-repository.anu.edu.au/bitstream/1885/65286/7/01_Davies_Earth%27s_surface_heat_flux_2010.pdf.jpg

We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by multiplying it by the total global area of that geologic domain. The averaging is done on a polygon set which results from an intersection of a 1 degree equal area grid with the original geology polygons; this minimises the adverse influence of clustering. These operations and estimates are derived accurately using methodologies from Geographical Information Science. We consider the virtually un-sampled Antarctica separately and also make a small correction for hot-spots in young oceanic lithosphere. A range of analyses is presented. These, combined with statistical estimates of the error, provide a measure of robustness. Our final preferred estimate is 47±2 TW, which is greater than previous estimates.