A Caltech Library Service

Seismic Cross Sections of the Upper Mantle

Anderson, Don L. (1984) Seismic Cross Sections of the Upper Mantle. Eos, 65 (19). p. 346. ISSN 0096-3941. doi:10.1029/EO065i019p00346-04.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Surface wave tomography is being used to map the seismic velocity and anisotropy of the upper mantle on a global basis [Nataf et al., Anisotropy and shear-velocity heterogeneities in the upper mantle, Geophys. Res. Lett., 11, 109-112, 1984]. The color figure shows cross sections of the upper 670 km of the mantle. (Note previous example published on the cover of Eos, April 17, 1984.) VSV is the velocity of vertically polarized shear waves, averaged with respect to azimuth. The orange regions are slow, presumably hot, regions of the mantle, although VSV can below due to crystal orientation, or anisotropy, as well as to high temperature. The ambiguity is removed by studying the anisotropy. The parameter XI is related to VSH-VSV, the difference in velocity between the two polarizations of shear waves. Olivine crystals oriented with the fast axis in the horizontal plane would give positive XI. This would be the expected situation for horizontal flow. Vertical flow is expected to give negative XI for an olivine-rich mantle. The cross sections for XI, with this interpretation, would be orange in regions of ascending and descending flow.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:© 1984 American Geophysical Union. Tomographic research at Caltech is supported by National Science Foundation grants EAR-8115236 and EAR-8317623. I thank Robert Clayton, Bradford Hager, and Adam Dziewonski for assistance in making the illustrations. This news item and photo was contributed by Don L. Anderson, Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125. Division of Geological Sciences Contribution No. 4113.
Funding AgencyGrant Number
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences4113
Issue or Number:19
Record Number:CaltechAUTHORS:20140506-140509236
Persistent URL:
Official Citation:Anderson, D. L. (1984), Seismic cross sections of the upper mantle, Eos Trans. AGU, 65(19), 346–346, doi:10.1029/EO065i019p00346-04.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:45537
Deposited By: Ruth Sustaita
Deposited On:06 May 2014 21:31
Last Modified:10 Nov 2021 17:13

Repository Staff Only: item control page