Under the thin oceanic plates the asthenosphere is usually much closer to the seafloor surface, and at mid-ocean ridges it rises to within a few kilometers of the ocean floor.

The upper part of the asthenosphere is believed to be the zone upon which the great rigid and brittle lithospheric plates of the Earth's crust move about. Due to the temperature and pressure conditions in the asthenosphere, rock becomes ductile, moving at rates of deformation measured in cm/yr over lineal distances eventually measuring thousands of kilometers. In this way, it flows like a convection current, radiating heat outward from the Earth's interior. Above the asthenosphere, at the same rate of deformation, rock behaves elastically and, being brittle, can break, causing faults. The rigid lithosphere is thought to "float" or move about on the slowly flowing asthenosphere, creating the movement of crustal plates.


Although its presence was suspected as early as 1926, the worldwide occurrence of the asthenosphere was confirmed by analyses of earthquake waves from the Great Chilean Earthquake of May 22, 1960.


  • Donald L. Turcotte and Gerald Schubert. Geodynamics, 2nd ed., Cambridge University Press 2001
  • GEMS Institute of higher education,Nepal.Environment Management Club, Kushal
  • An Introduction to the Solar System; McBride and Gilmour; Cambridge University Press 2004

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  • Asthenosphere — Asthénosphère L asthénosphère (du grec asthenos, sans résistance) est la partie ductile du manteau terrestre, directement située sous la lithosphère rigide. Ce concept apparaît à la fin des années 1960 avec la révolution de la tectonique des… …   Wikipédia en Français

  • asthénosphère — [ astenɔsfɛr ] n. f. • 1914; gr. astheneia « faiblesse » et sphère ♦ Géol. Couche non rigide du manteau supérieur de la Terre (entre 150 et 700 km de profondeur) sur laquelle flotte la lithosphère. ● asthénosphère nom féminin Zone située à l… …   Encyclopédie Universelle

  • asthenosphere — n. 1. the lower layer of the earth s crust, below the lithosphere. It is estimated as from fifty to several hundred miles thick. It is less rigid than the lithosphere, but still rigid enough to transmit some transverse seismic waves. [RHUD]… …   The Collaborative International Dictionary of English

  • asthenosphere — (n.) layer of the Earth s upper mantle, 1914, from Gk. asthenos (see ASTHENIA (Cf. asthenia)) + SPHERE (Cf. sphere) …   Etymology dictionary

  • asthenosphere — [as then′ə sfir΄] n. [< Gr asthenēs, weak (see ASTHENIA) + O + SPHERE] a zone in the upper mantle of the earth, consisting of hot, plastic rock, that underlies the solid lithosphere …   English World dictionary

  • Asthénosphère — L asthénosphère (du grec asthenos, sans résistance) est la partie ductile du manteau supérieur terrestre. Elle repose sous la lithosphère rigide et sur la mésosphère (manteau inférieur). Ce concept apparaît à la fin des années 1960 avec la… …   Wikipédia en Français

  • asthenosphere — /as then euh sfear /, n. Geol. 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… …   Universalium

  • asthenosphere — noun Etymology: Greek asthenēs weak + English o + sphere Date: 1914 a zone of a celestial body (as the earth) which lies beneath the lithosphere and within which the material is believed to yield readily to persistent stresses • asthenospheric… …   New Collegiate Dictionary

  • asthenosphere — noun the zone of the Earths upper mantle, below the lithosphere …   Wiktionary

  • asthenosphere —   layer of rock in the mantle approximately 80km deep and at a temperature of 1400°C. Rocks here become much softer and more easily deformed than in the lithosphere above …   Geography glossary

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