asthenosphere: Meaning and Definition of

as•then•o•sphere

Pronunciation: (as-then'u-sfēr"), [key]
— n. Geol.
  1. the region below the lithosphere, variously estimated as being from fifty to several hundred miles (eighty-five to several hundred kilometers) thick, in which the rock is less rigid than that above and below but rigid enough to transmit transverse seismic waves.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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