as·​theno·​sphere | \ as-ˈthe-nə-ˌsfir How to pronounce asthenosphere (audio) \

Definition of asthenosphere

: a zone of a celestial body (such as the earth) which lies beneath the lithosphere and within which the material is believed to yield readily to persistent stresses

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Other Words from asthenosphere

asthenospheric \ as-​ˌthe-​nə-​ˈsfir-​ik How to pronounce asthenosphere (audio) , -​ˈsfer-​ \ adjective

Examples of asthenosphere in a Sentence

Recent Examples on the Web These pieces, divided between older continental crust and younger oceanic crust, ride atop the gooey asthenosphere, a semiliquid layer of magma and partly melted rock. Gemma Tarlach, Discover Magazine, 12 June 2019 Exactly what mechanism or mechanisms are behind their movement is still debated, but are likely to include convection currents within the asthenosphere and the forces generated at the boundaries between plates. Lucia Perez Diaz, CNN, 5 Apr. 2018 Björn Winker, a mineralogist at the Johann Wolfgang Goethe University in Frankfurt, Germany, believes that the key to the asthenosphere is water. Brian Romans, WIRED, 13 Aug. 2007

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'asthenosphere.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of asthenosphere

1914, in the meaning defined above

History and Etymology for asthenosphere

Greek asthenḗs "weak" + -o- + -sphere — more at asthenia

Note: The term was introduced by the American geologist Joseph Barrell (1869-1919) in "The strength of the earth's crust. Part VI. Relations of isostatic movements to a sphere of weakness—the asthenosphere," Journal of Geology, vol. 22 (1914), p. 659: "The theory of isostasy shows that below the lithosphere there exists in contradistinction a thick earth-shell marked by a capacity to yield readily to long-enduring strains of limited magnitude …To give proper emphasis and avoid the repetition of descriptive clauses it needs a distinctive name. It may be the generating zone of the pyrosphere; it may be a sphere of unstable state, but this to a large extent is hypothesis and the reason for choosing a name rests upon the definite part it seems to play in crustal dynamics. Its comparative weakness is in that connection its distinctive feature. It may then be called the sphere of weakness—the asthenosphere…"

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The first known use of asthenosphere was in 1914

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Cite this Entry

“Asthenosphere.” Dictionary, Merriam-Webster, Accessed 26 Oct. 2021.

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Nglish: Translation of asthenosphere for Spanish Speakers Encyclopedia article about asthenosphere


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