Earth's multi-scale topographic response to global mantle flow

Rhodri Davies, Andrew Valentine, Stephan C Kramer, Nick Rawlinson, Mark Hoggard, Caroline Eakin, Cian R Wilson

    Research output: Contribution to journalArticlepeer-review

    63 Citations (Scopus)

    Abstract

    Earths surface topography is a direct physical expression of our planets dynamics. Most is isostatic, controlled by thickness and density variations within the crust and lithosphere, but a substantial proportion arises from forces exerted by underlying mantle convection. This dynamic topography directly connects the evolution of surface environments to Earths deep interior, but predictions from mantle flow simulations are often inconsistent with inferences from the geological record, with little con- sensus about its spatial pattern, wavelength and amplitude. Here, we demonstrate that previous comparisons between predic- tive models and observational constraints have been biased by subjective choices. Using measurements of residual topography beneath the oceans, and a hierarchical Bayesian approach to performing spherical harmonic analyses, we generate a robust estimate of Earths oceanic residual topography power spectrum. This indicates water-loaded power of 0.5 ± 0.35 km2 and peak amplitudes of up to ~0.8 ± 0.1 km at long wavelengths (~104 km), decreasing by roughly one order of magnitude at shorter wave- lengths (~103 km). We show that geodynamical simulations can be reconciled with observational constraints only if they incor- porate lithospheric structure and its impact on mantle flow. This demonstrates that both deep (long-wavelength) and shallow (shorter-wavelength) processes are crucial, and implies that dynamic topography is intimately connected to the structure and evolution of Earths lithosphere.
    Original languageEnglish
    Pages (from-to)845-850
    JournalNature Geoscience
    Volume12
    DOIs
    Publication statusPublished - 2019

    Fingerprint

    Dive into the research topics of 'Earth's multi-scale topographic response to global mantle flow'. Together they form a unique fingerprint.

    Cite this