0 the thin, almost liquid, layer under the hard rock that forms the outer layer of the earth --
1 the thin, almost liquid, layer under the hard rock that forms the outer layer of the earth --
The steep dip angle of the subducting plate can correspond to a thicker wedge of asthenosphere and therefore a greater source of fertile mantle material.
This decreasing in seismic waves velocity from lithosphere to asthenosphere could be caused by the presence of small percentage of melt in the asthenosphere.
The upward flow of the asthenosphere results in decompression melting, magmatic underplating and some volcanism that may occur in the rift area.
The upwelling of asthenosphere is not involved in the actual rifting process.
Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithosphere rides.
It was found that the asthenosphere had invaded the overlying lithosphere.
Several explanations have been proposed; a lower limit to the pliable asthenosphere, a phase transition, and most plausibly, depth-variation in the shear wave anisotropy.
Temperatures high enough to produce basaltic partial melt in this decaying thermal anomaly would be located near the base of the lithosphere and in the immediately underlying asthenosphere.
