3D shear wave velocity model of the crust and uppermost mantle beneath the Tyrrhenian basin and margins

Title3D shear wave velocity model of the crust and uppermost mantle beneath the Tyrrhenian basin and margins
Publication TypeJournal Article
Year of Publication2019
AuthorsManu-Marfo D., Aoudia A., Pachhai S., Kherchouche R.
JournalScientific Reports
Volume9
Date Published2019/03
Type of ArticleArticle
ISBN Number2045-2322
Accession NumberWOS:000460383600021
Keywordsambient-noise data; back-arc extension; constraints; insights; plate boundary; Science & Technology - Other Topics; sea; Seismology; subduction zone; tomography; vavilov basin
Abstract

The Tyrrhenian basin serves as a natural laboratory for back-arc basin studies in the Mediterranean region.Yet, little is known about the crust-uppermost mantle structure beneath the basin and its margins. Here, we present a new 3D shear-wave velocity model and Moho topography map for the Tyrrhenian basin and its margins using ambient noise cross-correlations. We apply a self-parameterized Bayesian inversion of Rayleigh group and phase velocity dispersions to estimate the lateral variation of shear velocity and its uncertainty as a function of depth (down to 100 km). Results reveal the presence of a broad low velocity zone between 40 and 80 km depth affecting much of the Tyrrhenian basin's uppermost mantle structure and its extension mimics the paleogeographic reconstruction of the Calabrian arc in time. We interpret the low-velocity structure as the possible source of Mid-Ocean Ridge Basalts- and Ocean Island Basalts- type magmatic rocks found in the southern Tyrrhenian basin. At crustal depths, our results support an exhumed mantle basement rather than an oceanic basement below the Vavilov basin. The 3D crust-uppermost mantle structure supports a present-day geodynamics with a predominant Africa-Eurasia convergence.

DOI10.1038/s41598-019-40510-z
Short TitleSci Rep
Student Publication: 
No