Imaging the Ethiopian Rift Region Using Transdimensional Hierarchical Seismic Noise Tomography

The Ethiopian Rift is a unique natural environment to study the different stages of evolution from initial continental rifting embryonic seafloor spreading. We used transdimensional hierarchical Bayesian seismic ambient noise tomography first construct group velocity maps across Afar, Main Rift, and adjoining plateaus, then inverted these for shear wave model. uppermost mantle ranges between 3.9 4.3 km/s, 5–15% lower than upper in PREM combined effect temperature partial melt needed explain 15% reduction mantle. Tectonic magmatic activities are not limited rift center, but instead widespread within crust beneath Afar. dominated by two belts, Wonji Fault Belt along axis Silti-Debre Zeit Zone on western side Central Rift; Boru-Toru structural high appears serve as transfer zone them, exhibiting relatively crustal velocities (3.6 km/s) at 14 km depth. Low persist flanks border faults, indicating that they still tectonically magmatically active. plateau characterized low-velocity anomaly, implying also Low-velocity linear belts further imaged eastern away active axes. These off-axis could represent failed or buried rifts.