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Science 22 January 1993:
Vol. 259. no. 5094, pp. 473 - 479
DOI: 10.1126/science.259.5094.473
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Articles

Gravity Field over Northern Eurasia and Variations in the Strength of the Upper Mantle

Mikhail G. Kogan 1 and Marcia K. McNutt 2

1 Institute of Mathematical Geophysics, Moscow, Russia
2 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139

The correlation of long-wavelength gravity anomalies in northern Eurasia with seismic velocity anomalies in the upper mantle reverses in sign between western and eastern Eurasia. The difference between western and eastern Eurasia can be explained by the presence of a low-viscosity zone in the uppermost mantle beneath eastern Eurasia that is absent to the west. The location of the lateral change in viscosity corresponds with the geologic boundary between the older shields and platforms of the Baltics, Russia, and Siberia and the younger, geologically active mountain belts of eastern Asia. This relation provides evidence that differences in the strength of the upper mantle control the locus of intracontinental deformation.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Continent-Ocean Chemical Heterogeneity in the Mantle Based on Seismic Tomography.
A. M. Forte, A. M. Forte, A. M. Dziewonski, and R. J. O'Connell (1995)
Science 268, 386-388
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Science. ISSN 0036-8075 (print), 1095-9203 (online)