Sharp Sides to the African Superplume
Top Cited Papers
- 7 June 2002
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 296 (5574) , 1850-1852
- https://doi.org/10.1126/science.1070698
Abstract
Beneath southern Africa is a large structure about 1200 kilometers across and extending obliquely 1500 kilometers upward from the core-mantle boundary with a shear velocity reduction of about 3%. Using a fortuitous set of SKS phases that travel along its eastern side, we show that the boundary of the anomaly appears to be sharp, with a width less than 50 kilometers, and is tilted outward from its center. Dynamic models that fit the seismic constraints have a dense chemical layer within an upwardly flowing thermal structure. The tilt suggests that the layer is dynamically unstable on geological time scales.Keywords
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