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

Daniel A. Frost; Margaret Susan Avery; Bruce Buffett; Bethany A. Chidester; Jie Deng; Susannah M. Dorfman; Zhi Li; Lijun Liu; Mingda Lv; Joshua F. Martin

doi:10.1029/2021gc009764

USGS · 70248970

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

Daniel A. Frost·Margaret Susan Avery·Bruce Buffett·Bethany A. Chidester·Jie Deng·Susannah M. Dorfman·Zhi Li·Lijun Liu·Mingda Lv·Joshua F. Martin

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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 Q CMB ∼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.

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Daniel A. Frost, Margaret Susan Avery, Bruce Buffett, Bethany A. Chidester, Jie Deng, Susannah M. Dorfman, Zhi Li, Lijun Liu, Mingda Lv, Joshua F. Martin. 2022-02-28. Multidisciplinary constraints on the thermal-chemical boundary between Earth's core and mantle. https://doi.org/10.1029/2021gc009764

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