Multidisciplinary constraints on the thermal-chemical boundary between Earth's core and mantle

Geochemistry, Geophysics, Geosystems
By: , and 

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Abstract

Heat flux from the core to the mantle provides driving energy for mantle convection thus powering plate tectonics, and contributes a significant fraction of the geothermal heat budget. Indirect estimates of core-mantle boundary heat flow are typically based on petrological evidence of mantle temperature, interpretations of temperatures indicated by seismic travel times, experimental measurements of mineral melting points, physical mantle convection models, or physical core convection models. However, previous estimates have not consistently integrated these lines of evidence. In this work, an interdisciplinary analysis is applied to co-constrain core-mantle boundary heat flow and test the thermal boundary layer (TBL) theory. The concurrence of TBL models, energy balance to support geomagnetism, seismology, and review of petrologic evidence for historic mantle temperatures supports QCMB ∼15 TW, with all except geomagnetism supporting as high as ∼20 TW. These values provide a tighter constraint on core heat flux relative to previous work. Our work describes the seismic properties consistent with a TBL, and supports a long-lived basal mantle molten layer through much of Earth's history.

Publication type Article
Publication Subtype Journal Article
Title Multidisciplinary constraints on the thermal-chemical boundary between Earth's core and mantle
Series title Geochemistry, Geophysics, Geosystems
DOI 10.1029/2021GC009764
Volume 23
Issue 3
Year Published 2022
Language English
Publisher American Geophysical Union
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description e2021GC009764, 34 p.
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