Definition of asthenosphere in English:
asthenosphere
noun əsˈθɛnəsfɪəæsˈθɛnəˌsfɪr
Geology 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.
Example sentencesExamples
- 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.
- 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.
- 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.
- 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.
- Scientists believe that below the lithosphere is a relatively narrow, mobile zone in the mantle called the asthenosphere.
- Magma from the asthenosphere rises up in the form of volcanos.
Derivatives
adjective
Geology We attribute the rapid return to subsidence in the basin to the confinement of abnormally hot asthenospheric mantle in the zone of continental break-up to the NW as sea-floor spreading commenced.
Example sentencesExamples
- The trace element and isotopic characteristics of these dykes imply derivation from an asthenospheric mantle source, which is likely to occur only as a result of regional lithospheric extension.
- Given the lack of evidence for significant magmatism in the area, the likely heat sources are either radiogenic, or elevated heat flux from asthenospheric mantle emplaced at a relatively shallow level beneath the orogen.
- They are interpreted to have been derived from subduction modified lithospheric and asthenospheric mantle sources.
- The space between this depth and the base of the model is filled with asthenospheric material with a constant density.
- We interpret them to be partial melts of asthenospheric mantle underlying the Antarctic Peninsula magmatic arc.
Origin
Early 20th century: from Greek asthenēs 'weak' + sphere.
Definition of asthenosphere in US English:
asthenosphere
nounæsˈθɛnəˌsfɪrasˈTHenəˌsfir
Geology 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.
Example sentencesExamples
- 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.
- Across the ridge, the asymmetric flow pattern in the asthenosphere will cause differential drag at the base of the lithosphere.
- 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.
- For one, it softens mantle rocks, thereby preparing the way for an asthenosphere - the soft layer underlying the plates.
- Magmas erupted in continental volcanic arcs typically contain components from many sources in the crust, lithospheric mantle and asthenosphere.
- Because the radioactive source of heat is deep within the mantle, the fluid asthenosphere circulates as convection currents underneath the solid lithosphere.
- Scientists believe that below the lithosphere is a relatively narrow, mobile zone in the mantle called the asthenosphere.
- Magma from the asthenosphere rises up in the form of volcanos.
- 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.
Origin
Early 20th century: from Greek asthenēs ‘weak’ + sphere.