Definition of asthenosphere in English:



  • The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

    ‘Because the downgoing slab of lithosphere is heavier than the plastic asthenosphere below, it tends to sink passively; and the older the lithosphere, the steeper the dip.’
    • ‘The models consist of a two-layered brittle-ductile system representing the overriding continental lithosphere, overlying a low-viscosity layer simulating the asthenosphere to provide isostatic support.’
    • ‘Scientists believe that below the lithosphere is a relatively narrow, mobile zone in the mantle called the asthenosphere.’
    • ‘Because the radioactive source of heat is deep within the mantle, the fluid asthenosphere circulates as convection currents underneath the solid lithosphere.’
    • ‘Across the ridge, the asymmetric flow pattern in the asthenosphere will cause differential drag at the base of the lithosphere.’
    • ‘Magmas erupted in continental volcanic arcs typically contain components from many sources in the crust, lithospheric mantle and asthenosphere.’
    • ‘Currents beneath the plates move the plates in different directions and driving all this is radioactivity deep in the earth's mantle which keeps the under layer - the asthenosphere - molten.’
    • ‘For one, it softens mantle rocks, thereby preparing the way for an asthenosphere - the soft layer underlying the plates.’
    • ‘Magma from the asthenosphere rises up in the form of volcanos.’



/asˈTHenəˌsfir/ /æsˈθɛnəˌsfɪr/


Early 20th century from Greek asthenēs ‘weak’+ sphere.