A Stirring Tale from inside Earth
A new theory describing how heat escapes from the planet's interior suggests a deeper, bumpier boundary separating the mantle's upper and lower layers.
References:
Kaneshima, S., and G. Helffrich. 1999. Dipping low-velocity layer in the mid-lower mantle: Evidence for geochemical heterogeneity. Science 283(March 19):1888.
Kellogg, L.H., B.H. Hager, and R.D. van der Hilst. 1999. Compositional stratification in the deep mantle. Science 283(March 19):1881.
van der Hilst, R.D., and H. Kárason. 1999. Compositional heterogeneity in the bottom 1000 kilometers of Earth's mantle: Toward a hybrid convection model. Science 283(March 19):1885.
Sources:
Kenneth C. Creager
University of Washington
Geophysics Program
Box 351650
Seattle, WA 98195-1650
Bradford H. Hager
Massachusetts Institute of Technology
Department of Earth, Atmospheric, and Planetary Sciences
Cambridge, MA 02139
Hrafnkell Kárason
Massachusetts Institute of Technology
Department of Earth, Atmospheric, and Planetary Sciences
Cambridge, MA 02139
Louise H. Kellogg
University of California, Davis
Department of Geology
Davis, CA 95616
Rob D. van der Hilst
Massachusetts Institute of Technology
Department of Earth, Atmospheric, and Planetary Sciences
Cambridge, MA 02139
From Science News, Vol. 155, No. 12, March 20, 1999, p. 180. Copyright © 1999, Science Service.
