Seafl oor topography and the thermal budget of Earth
نویسنده
چکیده
The subsidence of an aging seafl oor starts to slow down at ∼70 m.y. old with respect to that expected from simple half-space cooling, and this phenomenon has long been known as seafl oor fl attening. The fl attening signal remains even after removal of the infl uence of the emplacement of hotspot islands and oceanic plateaus. The combination of small-scale convection and radiogenic heating has been suggested as a mechanism to explain seafl oor fl attening, and this study explores the possibility of using the magnitude of seafl oor fl attening to constrain the amount of radiogenic heating in the convecting mantle. By comparison of properly scaled geodynamic expectations with the observed age-depth relation of the normal seafl oor, the mantle heat production is estimated to be ~12 ± 3 TW, which supports geochemistry-based estimates. A widely held notion that small-scale convection enhances cooling, thus being unable to explain seafl oor fl attening, is suggested to be incorrect. The ability to accurately interpret the age-depth relation of seafl oor based on the thermal budget of Earth has an important bearing on the future theoretical study of early Earth evolution. *[email protected] Korenaga, J., 2015, Seafl oor topography and the thermal budget of Earth, in Foulger, G.R., Lustrino, M., and King, S.D., eds., The Interdisciplinary Earth: A Volume in Honor of Don L. Anderson: Geological Society of America Special Paper 514 and American Geophysical Union Special Publication 71, p. 167–185, doi:10.1130/2015.2514(11). For permission to copy, contact [email protected]. © 2015 The Geological Society of America. All rights reserved. 2015 The Geological Society of America Special Paper 514 American Geophysical Union Special Publication 71
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