asthenosphere

[ as-then-uh-sfeer ]

nounGeology.
  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.

Compare Meanings

Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.

Origin of asthenosphere

1
First recorded in 1910–15; from Greek asthen(ḗs) “frail, weak, sickly” + -o- + -sphere;see asthenia

Words Nearby asthenosphere

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for asthenosphere

asthenosphere

/ (əsˈθiːnəˌsfɪə, -ˈθɛn-) /


noun
  1. a thin semifluid layer of the earth (100–200 km thick), below the outer rigid lithosphere, forming part of the mantle and thought to be able to flow vertically and horizontally, enabling sections of lithosphere to subside, rise, and undergo lateral movement: See also isostasy

Origin of asthenosphere

1
C20: from astheno-, from Greek asthenēs weak + sphere

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for asthenosphere

asthenosphere

[ ăs-thĕnə-sfîr′ ]


  1. The upper part of the Earth's mantle, extending from a depth of about 75 km (46.5 mi) to about 200 km (124 mi). The asthenosphere lies beneath the lithosphere and consists of partially molten rock. Seismic waves passing through this layer are significantly slowed. Isostatic adjustments (the depression or uplift of continents by buoyancy) take place in the asthenosphere, and magma is believed to be generated there. Compare atmosphere hydrosphere lithosphere.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.