A Complex Mantle Plume Head Below East Africa-Arabia Shaped by the Lithosphere-Asthenosphere Boundary Topography

21 pages, 9 figures, supporting information https://doi.org/10.1029/2022GC010610.-- Data Availability Statement: Seismic data from network codes marked in Figure 3 were freely available from several data centers including: the IRIS Data Management Center (https://ds.iris.edu/ds/nodes/dmc/); the GEOFON Data Centre of the GFZ (https://geofon.gfz-potsdam.de/waveform/archive); the RESIF seismic data portal (https://seismology.resif.fr/); Observatories and Research Facilities for European Seismology (http://orfeus-eu.org/webdc3/); the National Observatory of Athens (http://bbnet.gein.noa.gr); the Turkish Earthquake Research Institute KOERI (http://eida-service.koeri.boun.edu.tr); and the Italian Istituto Nazionale di Geofisica e Vulcanologia INGV (http://webservices.ingv.it). Table S2 in Supporting Information S1 provides details on the network and station codes downloaded from each data center. We thank all the network operators who contributed data to these data centers. The tomographic model is available to download at https://nlscelli.wixsite.com/ncseismology/af2019. It is also deposited to the online IRIS EMC-Earth Models repository (https://doi.org/10.17611/dp/emc.2022.af2019.1)
Hot plumes rising from Earth's deep mantle are thought to cause uplift, rifting and large igneous province (LIP) emplacement. LIP volcanism in continents often spans tens of Ma and scatters unevenly over broad areas. This has been attributed to lateral flow of hot plume material, but observational evidence on such flow is scarce. New waveform tomography with massive data sets reveals detailed seismic velocity structure beneath the East Africa-Arabia region, where these processes occur at present. It shows interconnected sub-lithospheric corridors of hot, partially molten rock, fed by three mantle upwellings beneath Kenya, Afar, and Levant. The spatio-temporal distribution of the volcanism suggests that we are witnessing an integral plume head, which morphed into a three-pointed star by ponding and channeling within thin-lithosphere corridors. Plate reconstructions indicate that it spread south-to-north since ∼45 Ma. These results suggest that complex-shape plume heads can explain the enigmatic, scattered LIP volcanism and are, probably, an inherent feature of plume-continent interaction
This work was supported by the Science Foundation Ireland (SFI) Grants 13/CDA/2192 and 16/IA/4598, the latter co-funded by the Geological Survey of Ireland and the Marine Institute. This work has been completed in the framework of the project 3D Earth funded by the European Space Agency (ESA) as a Support to Science Element (STSE). C.C. acknowledges the grant CEX2019-000928-S funded by AEI 10.13039/501100011033