Report

Elastic Moduli of Wadsleyite (β-Mg2SiO4) to 7 Gigapascals and 873 Kelvin

See allHide authors and affiliations

Science  31 Jul 1998:
Vol. 281, Issue 5377, pp. 675-677
DOI: 10.1126/science.281.5377.675

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Simultaneous sound velocity measurements and x-ray diffraction studies were made on wadsleyite (β-Mg2SiO4) to 7 gigapascals and 873 kelvin. The calculated adiabatic bulk (K) and shear (G) moduli yieldK (at room conditions) = 172(2) gigapascals,dK/dP = 4.2(1), anddK/dT = −0.012(1) gigapascals per kelvin, and G (at room conditions) = 113(1) gigapascals,dG/dP = 1.5(1), anddG/dT = −0.017(1) gigapascals per kelvin, respectively. The data imply that the P andS wave velocity contrasts between olivine and wadsleyite require an olivine amount of 38 to 39 percent in the upper mantle to satisfy the observed 410-kilometer discontinuity, but 55 to 60 percent to account for the velocity increase through the transition zone.

View Full Text