Numerical modelling of lithosphere-asthenosphere interaction and intraplate deformation in the Gulf of Guinea

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.

Downloads

Download Preprint

Authors

Jaime Almeida , Hamzeh Mohammadigheymasi, Marta Neres, Stéphanie Dumont

Abstract

To present day, the phenomenon of intraplate deformation and its associated earthquakes remain elusive. In this work, we argue that intraplate deformation may result from the interaction between lithospheric and upper mantle dynamic processes. To this extent, we targeted the Gulf of Guinea and adjacent Western Africa, a region with both low plate velocities and clear asthenosphere dynamics, allowing us to isolate the individual underlying dynamic constraints which govern intraplate deformation. Thus, here we present 3D numerical geodynamic models of the asthenosphere-lithosphere interaction in the Gulf of Guinea, ran with the state-of-the-art modelling code LaMEM. We employ different initial/boundary conditions such as: (a) identical vs different spreading rates for the varying segments of the Atlantic mid-ocean ridge, (b) the presence/absence of weak zones (e.g., the Romanche/Central-African shear zones), and (c) the effect exerted by an active mantle plume, with a varying ascension velocity. Seismic data was used to evaluate the models and their validity. Our results suggest that intraplate deformation within the Gulf of Guinea is influenced by the spreading rate of the mid-ocean ridge, with stress being localized around the ocean-continent transition and existing shear zones. They also suggest that the existence of an underlying stress source (e.g., a mantle plume) beneath the Cameroon region is crucial to explain the epicenter distribution/deformation in the region.

DOI

https://doi.org/10.31223/X5GH7K

Subjects

Geology, Geophysics and Seismology, Tectonics and Structure

Keywords

intraplate deformation, Seismicity, numerical modelling, Gulf of Guinea, mantle plumes, Geodynamics

Dates

Published: 2024-10-31 16:16

Last Updated: 2024-10-31 20:16

License

CC BY Attribution 4.0 International