EGU22-562, updated on 08 Oct 2023
https://doi.org/10.5194/egusphere-egu22-562
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Toward a three-dimensional tomographic model of the Pacific upper mantle with full resolution and uncertainties

Franck Latallerie, Christophe Zaroli, Sophie Lambotte, and Alessia Maggi
Franck Latallerie et al.
  • Institut Terre Environnement Strasbourg, University of Strasbourg, France (flatallerie@unistra.fr)

Tomographic models suffer from unevenly distributed noisy data and therefore have complicated resolution and uncertainties that can hinder their interpretation. Using linear Backus & Gilbert inversion, it is possible to obtain tomographic models with resolution and uncertainties in a single step. Using such a method, we aim to produce a three-dimensional tomographic model of the Pacific upper mantle from surface-wave data. To linearise the forward problem, we use finite-frequency theory to describe the sensitivity of surface-wave phase-delays to the three-dimensional shear-wave velocity. We build a data-base of phase-delay measurements for surface-waves that cross the Pacific Ocean. We estimate the data uncertainties caused by measurement errors using a multitaper technique and those caused by poor knowledge of the seismic source and crust by a Monte-Carlo method. Using the Backus & Gilbert approach, the phase-delay dataset, and the data uncertainty estimates, we obtain a model of the shear-wave velocity of the Pacific upper mantle together with its three-dimensional resolution and uncertainties. These allow us to discuss, using robust statistical arguments, the existence and the three-dimensional organisation of structures we expect to see in the Pacific upper mantle, such as plume-like upwellings or small-scale sub-lithospheric convections.

How to cite: Latallerie, F., Zaroli, C., Lambotte, S., and Maggi, A.: Toward a three-dimensional tomographic model of the Pacific upper mantle with full resolution and uncertainties, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-562, https://doi.org/10.5194/egusphere-egu22-562, 2022.

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