A heat flow based cooling model for tectonic plates

Abstract

Plate tectonic theory predicts subsidence and decreasing heat flow as young, hot buoyant lithosphere ages and cools. Oceanic cooling models are re-calibrated to a new ‘hydrothermal-free’ heat flow dataset to provide a better fit to heat flow on old (>80Ma) seafloor while simultaneously allowing for a more reasonable mantle potential temperature (1350°C). The plate model (constant basal temperature) and chablis (constant basal temperature and constant basal heat flow) are tested as viable solutions to the observed data. Both models fit to reasonable values of misfit, but only the plate cooling model is acceptable after considering additional statistical constraints. The best-fitting plate model results in a thinner lithospheric thickness (90km) than previous estimates. These results improve estimates of global heat loss rate through oceanic crust (29.4TW, ∼44TW globally) and improves the estimated temporal evolution of the thermal structure of oceanic lithosphere suggesting a shallower lithosphere–asthenosphere boundary. This model can serve as a reference for estimating the global redistribution of heat by ventilated hydrothermal circulation through young seafloor.