Linking lowermost mantle structure, core-mantle boundary heat flux and mantle plume formation

Mingming Li, Shijie Zhong, Peter Olson

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The dynamics of Earth's lowermost mantle exert significant control on the formation of mantle plumes and the core-mantle boundary (CMB) heat flux. However, it is not clear if and how the variation of CMB heat flux and mantle plume activity are related. Here, we perform geodynamic model experiments that show how temporal variations in CMB heat flux and pulses of mantle plumes are related to morphologic changes of the thermochemical piles of large-scale compositional heterogeneities in Earth's lowermost mantle, represented by the large low shear velocity provinces (LLSVPs). We find good correlation between the morphologic changes of the thermochemical piles and the time variation of CMB heat flux. The morphology of the thermochemical piles is significantly altered during the initiation and ascent of strong mantle plumes, and the changes in pile morphology cause variations in the local and the total CMB heat flux. Our modeling results indicate that plume-induced episodic variations of CMB heat flux link geomagnetic superchrons to pulses of surface volcanism, although the relative timing of these two phenomena remains problematic. We also find that the density distribution in thermochemical piles is heterogeneous, and that the piles are denser on average than the surrounding mantle when both thermal and chemical effects are included.

Original languageEnglish (US)
Pages (from-to)10-29
Number of pages20
JournalPhysics of the Earth and Planetary Interiors
Volume277
DOIs
StatePublished - Apr 1 2018
Externally publishedYes

Fingerprint

core-mantle boundary
mantle structure
mantle plume
piles
plumes
heat flux
Earth mantle
pile
mantle
chemical effects
ascent
geodynamics
pulses
volcanism
temporal variation
plume
temperature effects
density distribution
time measurement
shear

Keywords

  • CMB heat flux
  • Geomagnetic superchrons
  • Large igneous provinces
  • Mantle plume
  • Thermochemical piles

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Geophysics
  • Physics and Astronomy (miscellaneous)
  • Space and Planetary Science

Cite this

Linking lowermost mantle structure, core-mantle boundary heat flux and mantle plume formation. / Li, Mingming; Zhong, Shijie; Olson, Peter.

In: Physics of the Earth and Planetary Interiors, Vol. 277, 01.04.2018, p. 10-29.

Research output: Contribution to journalArticle

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