<span>The asthenosphere is a part of the upper mantle just below
the </span>lithosphere<span> <span>that is involved in </span></span>plate tectonic
movement<span> <span>and </span></span>isostatic<span> <span>adjustments. The
lithosphere-asthenosphere boundary is conventionally taken at the 1300 °C </span></span>isotherm<span>, above which the mantle behaves in a rigid fashion and below
which it behaves in a </span>ductile<span> fashion. a</span><span>nd </span>flows very slowly, in a manner<span> similar
to the ice at a bottom of a glacier.</span>
The word lithosphere is the outermost crust of the earth, which consists of the roast of the planet and the rest of the fur. The tectonic plate, which is also known as the asthenosphere, has fractured mostly.
The substance brittles when under tension, separates without significant plastic deformations and behaves like a ductile, a shape acting to move very slowly, like the ice at the foot of a glacier.
