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Moore, C, Wright, TJ orcid.org/0000-0001-8338-5935 and Hooper, A orcid.org/0000-0003-4244-6652 (2021) Rift Focusing and Magmatism During Late-Stage Rifting in Afar. Journal of Geophysical Research: Solid Earth, 126 (10). e2020JB021542. ISSN 2169-9356
Abstract
Processes that facilitate the transition between continental rifting and sea-floor spreading remain unclear. Variations in the spatial distribution of extension and magmatism through Afar and into the Red Sea are indicative of temporal evolution of the rifting process. We develop a time series of Sentinel-1 interferometric synthetic aperture radar (InSAR) observations of ground deformation covering the whole Afar rift zone from 2014 to 2019, to study the distribution of extension. By incorporating Global Navigation Satellite System observations, we resolve 3D average velocities in the vertical, rift-perpendicular, and rift-parallel directions. Results show the spatial distribution of long-wavelength deformation over the rift zone, as well as deformation at individual volcanic centers, including Dallol, Nabro, and Erta ’Ale. We find that in northern and central Afar, the majority of extension is accommodated close to the rift axis (±15–30 km). In southern Afar, near the Nubia-Arabia-Somalia triple junction, amagmatic extension is distributed over 80–160 km, which may indicate an increase in rift focusing with rift maturity. We also observe rapid surface uplift and rift-perpendicular extension at the Dabbahu-Manda-Hararo rift segment with velocities of 33 ± 4 mm/yr and 37 ± 4 mm/yr respectively. These are higher than the background extension rate of 18–20 mm/yr, but have decreased by 55%–70% since 2006–2010. The data suggests that this is due to an ongoing long-lived response to the 2005–2010 rifting episode, with potential continued processes below the rift segment including a lower-crustal viscous response and magma movement. Continued observations of surface deformation provide key constraints on tectono-magmatic processes involved in rift development.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Nov 2021 16:35 |
Last Modified: | 14 Jun 2022 14:15 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1029/2020jb021542 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:180345 |
Available Versions of this Item
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Rift Focussing and Magmatism During Late-Stage Rifting in Afar, Ethiopia. (deposited 14 Jun 2022 14:13)
- Rift Focusing and Magmatism During Late-Stage Rifting in Afar. (deposited 16 Nov 2021 16:35) [Currently Displayed]