Mantle transition zone variations beneath the Ethiopian Rift and Afar
Domaine:
geospatialCréateur:
CorHetBla
Éditeur:
ETHETH
Éditeur:
Ame
Hôte:
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 δVₛ > 3 %) upper mantle. The 660 discontinuity is shown to have variations in depth (665–705 km) over short length scales (<200 km). This results in a MTZ with a ‘normal’ average thickness of 244 km, (i.e., within error of the observed global average). However, local thickness variations (<230 km to >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.
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