Terrestrial Heat Flow Patrick Loury and Alex Turner Map of preferred global heat flux (mW m -2 ) Davies and Davies, 2010

Heat Loss from the Oceans Pollack et al., 1993 Stein et al., 1994

Calculated Heat Loss from Oceanic Crust Radius of the Earth = 6,378,100 m Surface Area = 4= 4 (3.14) (6,378,100 m²) = E 14 m² Oceanic Crust accounts for ~60% of the Earth’s surface (5.112 E 14 m²)(.6) = E 14 m² Mean heat flow from oceanic terrains (as calculated from Pollack at al., 1993) = 101 ± 2.2 mW m -2 Total Heat loss contribution from oceanic crust: (3.067 E 14 m²) x (101 ± 2.2 mW m -2 ) = E 16 mW = ~31 TW

Heat Loss from the Continents Controlling Factors: Surface area of the material Age of the last thermo-tectonic event Chemical composition Heat flow measurements* High: Quaternary units (mean: 82.0 mW m -2 ) Low: Cambrian Units (mean: 50.5 mW m -2 ) Average Effective Heat Flow for Continental Crust: 66.3 mW m -2 *(Davies and Davies, 2010) Calculated Heat Loss from Continental Crust: Assuming continental crust accounts for ~40% of Earth’s total surface Area: Continental Heat Loss = (66.3 mW m -2 )(0.4 x (5.112 x m)) = 13.5 TW

Global Heat Loss Estimates of Global Heat Loss Davies and Davies (2010): 46.7 ± 2.0 TW Pollack, et al. (1993): 44.2 TW This model: 44.5 TW Oceanic Contribution: ~70% Continental Contribution: ~30% Potential Error Sources: Limited available areas for heat flow measurements Calculation of effective heat flow values Areas of abnormally high or low heat flow Surface Area Assumptions: CC/OC proportion Spherical earth