Journal
SCIENCE
Volume 303, Issue 5656, Pages 351-353Publisher
AMER ASSOC ADVANCEMENT SCIENCE
DOI: 10.1126/science.1091524
Keywords
-
Categories
Ask authors/readers for more resources
We applied global waveform tomography to model radial anisotropy in the whole mantle. We found that in the last few hundred kilometers near the core-mantle boundary, horizontally polarized S-wave velocities (V(SH)) are, on average, faster (by similar to1%) than vertically polarized S-wave velocities (V(SV)), suggesting a large-scale predominance of horizontal shear. This confirms that the D region at the base of the mantle is also a mechanical boundary layer for mantle convection. A notable exception to this average signature can be found at the base of the two broad low-velocity regions under the Pacific Ocean and under Africa, often referred to as superplumes, where the anisotropic pattern indicates the onset of vertical flow.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available