A sudden increase in velocity occurs at the top of this region, known as the Moho discontinuity.
The Chikyu Hakken mission is attempting to explore this region. This region contains such polymorphs of rocks as wadsleyite and ringwoodite, as well as the perovskite-structured pyroxene enstatite. The D'' [D double prime] region is found in its homogeneous lower portion, while a Low Velocity Zone extends several kilometers in this layer. A sudden increase in velocity occurs at the top of this region, known as the Moho discontinuity. For 10 points, name this layer of the Earth above the outer core and below the crust.
The Chikyu Hakken mission is attempting to explore this region.
{mantle}