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 — 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… … Wikipedia
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 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