The mantle transition zone (MTZ) structure beneath the Ethiopian Rift and Afar is mapped using receiver functions. The 410 discontinuity is flat and regionally depressed by 30-40 km, most likely due to a hot (=+250 °C) and slow (average dV > 3 %) upper mantle. The 660 discontinuity is shown to have variations in depth (665-705 km) over short length scales (260 km) indicate possible compositional/chemical heterogeneities and elevated ambient temperatures near the base of the MTZ. These observations provide evidence for a link between the low velocity anomalies of the Ethiopian upper mantle and the African Superplume in the lower mantle.
Cornwell, D. G., Hetényi, G., & Blanchard, T. D. (2011). Mantle transition zone variations beneath the Ethiopian Rift and Afar: Chemical heterogeneity within a hot mantle? Geophysical Research Letters, 38(16). https://doi.org/10.1029/2011GL047575