Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves
Abstract The evolution of the Sicily Channel Rift Zone (SCRZ) is thought to accommodate the regional tectonic stresses of the Calabrian subduction system. Much of the observations we have today are either limited to the surface or to the upper crust or deeper from regional seismic tomography, missin...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2022-10-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Online Access: | https://doi.org/10.1029/2022GC010394 |
| _version_ | 1797638101465563136 |
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| author | M. R. Agius F. Magrini G. Diaferia E. D. Kästle F. Cammarano C. Faccenna F. Funiciello M. van derMeijde |
| author_facet | M. R. Agius F. Magrini G. Diaferia E. D. Kästle F. Cammarano C. Faccenna F. Funiciello M. van derMeijde |
| author_sort | M. R. Agius |
| collection | DOAJ |
| description | Abstract The evolution of the Sicily Channel Rift Zone (SCRZ) is thought to accommodate the regional tectonic stresses of the Calabrian subduction system. Much of the observations we have today are either limited to the surface or to the upper crust or deeper from regional seismic tomography, missing important details about the lithospheric structure and dynamics. It is unclear whether the rifting is passive from far‐field extensional stresses or active from mantle upwelling beneath. We measure Rayleigh‐and Love‐wave phase velocities from ambient seismic noise and invert for 3‐D shear‐velocity and radial anisotropic models. Variations in crustal S‐velocities coincide with topographic and tectonic features. The Tyrrhenian Sea has a ∼10 km thin crust, followed by the SCRZ (∼20 km). The thickest crust is beneath the Apennine‐Maghrebian Mountains (∼55 km). Areas experiencing extension and intraplate volcanism have positive crustal radial anisotropy (VSH > VSV); areas experiencing compression and subduction‐related volcanism have negative anisotropy. The crustal anisotropy across the Channel shows the extent of the extension. Beneath the Tyrrhenian Sea, we find very low sub‐Moho S‐velocities. In contrast, the SCRZ has a thin mantle lithosphere underlain by a low‐velocity zone. The lithosphere‐asthenosphere boundary rises from 60 km depth beneath Tunisia to ∼33 km beneath the SCRZ. Negative radial anisotropy in the upper mantle beneath the SCRZ is consistent with vertical mantle flow. We hypothesize a more active mantle upwelling beneath the rift than previously thought from an interplay between poloidal and toroidal fluxes related to the Calabrian slab, which in turn produces uplift at the surface and induces volcanism. |
| first_indexed | 2024-03-11T12:57:46Z |
| format | Article |
| id | doaj.art-a6737c24fa7747a3a28ccca46314b5cb |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:57:46Z |
| publishDate | 2022-10-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-a6737c24fa7747a3a28ccca46314b5cb2023-11-03T16:56:07ZengWileyGeochemistry, Geophysics, Geosystems1525-20272022-10-012310n/an/a10.1029/2022GC010394Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface WavesM. R. Agius0F. Magrini1G. Diaferia2E. D. Kästle3F. Cammarano4C. Faccenna5F. Funiciello6M. van derMeijde7Dipartimento di Scienze Università Roma Tre Rome ItalyJohannes Gutenberg‐Universität Mainz Mainz GermanyIstituto Nazionale di Geofisica e Vulcanologia Rome ItalyInstitute of Geological Sciences Freie Universität Berlin Berlin GermanyDipartimento di Scienze Università Roma Tre Rome ItalyDipartimento di Scienze Università Roma Tre Rome ItalyDipartimento di Scienze Università Roma Tre Rome ItalyUniversity of Twente Enschede The NetherlandsAbstract The evolution of the Sicily Channel Rift Zone (SCRZ) is thought to accommodate the regional tectonic stresses of the Calabrian subduction system. Much of the observations we have today are either limited to the surface or to the upper crust or deeper from regional seismic tomography, missing important details about the lithospheric structure and dynamics. It is unclear whether the rifting is passive from far‐field extensional stresses or active from mantle upwelling beneath. We measure Rayleigh‐and Love‐wave phase velocities from ambient seismic noise and invert for 3‐D shear‐velocity and radial anisotropic models. Variations in crustal S‐velocities coincide with topographic and tectonic features. The Tyrrhenian Sea has a ∼10 km thin crust, followed by the SCRZ (∼20 km). The thickest crust is beneath the Apennine‐Maghrebian Mountains (∼55 km). Areas experiencing extension and intraplate volcanism have positive crustal radial anisotropy (VSH > VSV); areas experiencing compression and subduction‐related volcanism have negative anisotropy. The crustal anisotropy across the Channel shows the extent of the extension. Beneath the Tyrrhenian Sea, we find very low sub‐Moho S‐velocities. In contrast, the SCRZ has a thin mantle lithosphere underlain by a low‐velocity zone. The lithosphere‐asthenosphere boundary rises from 60 km depth beneath Tunisia to ∼33 km beneath the SCRZ. Negative radial anisotropy in the upper mantle beneath the SCRZ is consistent with vertical mantle flow. We hypothesize a more active mantle upwelling beneath the rift than previously thought from an interplay between poloidal and toroidal fluxes related to the Calabrian slab, which in turn produces uplift at the surface and induces volcanism.https://doi.org/10.1029/2022GC010394 |
| spellingShingle | M. R. Agius F. Magrini G. Diaferia E. D. Kästle F. Cammarano C. Faccenna F. Funiciello M. van derMeijde Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves Geochemistry, Geophysics, Geosystems |
| title | Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves |
| title_full | Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves |
| title_fullStr | Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves |
| title_full_unstemmed | Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves |
| title_short | Shear‐Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves |
| title_sort | shear velocity structure and dynamics beneath the sicily channel and surrounding regions of the central mediterranean inferred from seismic surface waves |
| url | https://doi.org/10.1029/2022GC010394 |
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