Images of the East African Rift System by Global Adaptive-Resolution Surface-Wave Tomography

Autor(en)

Félicie Korostelev, Yang Lu, Fabrizio Magrini, Lapo Boschi, Sylvie Leroy, William Vétel

Abstrakt

In this study we map the entire East African Rift System (EARS) within a global surface-wave velocity model to better constrain the structure of the underlying mantle, as well as patterns that might be associated with its continuation in the Mozambique Channel. We use all publicly available seismograms from the African continent, amounting to 1296 stations and more than 30 years of recordings. From these data, we obtain dispersion curves using both ambient noise and teleseismic earthquakes. To our measurements, we add global counterparts and jointly invert them for phase-velocity maps. We exploit a linearized inversion based on the ray theory, with an adaptive parameterization that allows for maximizing the resolution of the final maps based on the density of data coverage. We thus image the main African cratons and also some of the Archean blocks within them. We highlight the discontinuous nature of magmatic activity along the EARS and also display low-velocity anomalies beneath the Comores Archipelago, Madagascar and Bassas da India volcanic islands and seamounts. This last low-velocity anomaly is in the direct continuation of the EARS and could unveil an important magmatic system in the Mozambique Channel.

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

Icm & Sorbonne University, Università Degli Studi Roma Tre, Johannes Gutenberg-Universität Mainz, Università degli Studi di Padova, Université Paris VI - Pierre-et-Marie-Curie, TOTAL S.A., University of California, Los Angeles

Journal

Journal of Geophysical Research - Solid Earth

Band

127

Anzahl der Seiten

18

ISSN

2169-9313

DOI

https://doi.org/10.1029/2021JB023570

Publikationsdatum

06-2022

Peer-reviewed

Ja

ÖFOS 2012

105122 Seismik

Schlagwörter

ASJC Scopus Sachgebiete

Geochemistry and Petrology, Geophysics, Earth and Planetary Sciences (miscellaneous), Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/40f85027-932c-4a51-a04d-37d8252a4cd3