Uppermost mantle (Pn) velocity model for the Afar region, Ethiopia: an insight into rifting processes
Stork, A.L. and Stuart, G.W. and Henderson, C.M. and Keir, D. and Hammond, James O.S. (2013) Uppermost mantle (Pn) velocity model for the Afar region, Ethiopia: an insight into rifting processes. Geophysical Journal International 193 (1), pp. 321-328. ISSN 0956-540X.
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Abstract
The Afar Depression, Ethiopia, offers unique opportunities to study the transition from continental rifting to oceanic spreading because the process is occurring onland. Using traveltime tomography and data from a temporary seismic deployment, we describe the first regional study of uppermost mantle P-wave velocities (VPn). We find two separate low VPn zones (as low as 7.2 km s−1) beneath regions of localized thinned crust in northern Afar, indicating the existence of high temperatures and, potentially, partial melt. The zones are beneath and off-axis from, contemporary crustal magma intrusions in active magmatic segments, the Dabbahu-Manda-Hararo and Erta'Ale segments. This suggests that these intrusions can be fed by off-axis delivery of melt in the uppermost mantle and that discrete areas of mantle upwelling and partial melting, thought to characterize segmentation of the uppermost mantle at seafloor spreading centres, are initiated during the final stages of break-up.
Metadata
| Item Type: | Article |
|---|---|
| Keyword(s) / Subject(s): | seismicity and tectonics, seismic tomography, continental margins: divergent |
| School: | School of Science > Earth and Planetary Sciences |
| Depositing User: | Sarah Hall |
| Date Deposited: | 19 May 2016 15:21 |
| Last Modified: | 12 Feb 2021 06:59 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/15241 |
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