HR: 09:05h
AN: S11A-04    [PDF]
TI: An explanation for the surface area of continents versus oceans
AU: * Lenardic, A
EM: adrian@esci.rice.edu
AF: Rice University, Department of Earth Science - MS 126, Houston, TX 77251-1892 United States
AU: Moresi, L
AF: Monash University, School of Mathematical Sciences, Building 8, Victoria, 3800 Australia
AU: Jellinek, A
AF: University of Toronto, Department of Physics, 60 St. George St., Toronto, Ont M5S 1A7 Canada
AU: Manga, M
AF: University of California, Department of Earth and Planetary Science, 307 McCone Hall, MC 4767, Berkeley, CA 94720-4767 United States
AB: The Earth's surface is approximately 40 percent continental and 60 percent oceanic. We present a theory of the Earth's internal heat loss that provides a thermal explanation for the 40-60 split. The theory, which is shown to be consistent with numerical simulations and laboratory experiments, couples oceanic and continental heat transfer modes and predicts that the observed surface area of continental lithosphere is near optimal in the sense that it maximizes the Earth's global heat flow. It also predicts the surface area that would maximize heat flow in the geologic past when the Earth had more internal heat to lose. This allows a continental growth curve to be constructed that maximizes global heat flow over geologic time. The theoretical curve is consistent with growth curves based on geochemical observation.
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8121 Dynamics, convection currents and mantle plumes
DE: 8130 Heat generation and transport
DE: 8149 Planetary tectonics (5475)
DE: 8159 Rheology--crust and lithosphere
SC: Seismology [S]
MN: 2003 Fall Meeting