Richard Muller proposed that comet impacts could cause "avalanches" in the region immediately below this one.
Richard Muller proposed that comet impacts could cause "avalanches" in the region immediately below this one. That thin boundary lying below this region is home to ultra low velocity zones. After leaving this region, P-waves turn into K-waves, then become P-waves when they cross through it again. Most of the inner half of this region is composed of post-perovskite. WJ Morgan proposed that hotspots were caused by upwelling in this region. This region's upper section, dominated by pyroxene and olivine, is separated from its lower section by the 660 kilometer discontinuity. The Gutenberg discontinuity lies just below this layer's D double prime layer. Stretching to 2800 kilometers below the surface is, for 10 points, what layer, making up 85% of Earth's volume?
Richard Muller proposed that comet impacts could cause "avalanches" in the region immediately below this one.
lower mantle