Abstract

The talk will take a look at close look at processes at different scales in the East African Rift System (EARS) using mostly seismological tools. Starting in the deep mantle using shear-wave splitting, we deduce the dynamics of the African Large Low Shear Velocity Province and how these may partially drive upper mantle flow which, in turn, may facilitate rifting and further interacts with the topography of lithosphere asthenosphere boundary. We infer the influence of melt along the EARS and focus on a region at the margin of the Tanzanian craton, where carbon is advected through the Proterozoic mobile belt as evidenced by strong CO2 degassing across rift faults and the existence of Earth's only currently active carbonatite volcano Oldoinyo Lengai. We then focus on the crustal scale of the rifting process by analyzing the interplay between rifting and volcanism using earthquakes, focal mechanisms and attenuation imaging. These results, together with the analysis and location of deeper volcanic tremor, shows how Oldoinyo Lengai is underlain by a transcrustal magmatic plumbing system with distinct areas of melt transport and storage. Using acoustic and satellite-based thermal data, the talk will end with analyzing eruptions at this peculiar volcano.