An inner segment of the Earth which is rigid, dense, and solid and lies directly beneath the Moho is called th?

The "Moho," is the boundary where Earth's crust meets Earth's upper mantle (approximately 31 mi/50 km below the surface), and where seismic waves travel at a different and more rapid rate than the crust or mantle. The Moho is named after Andrija Mohorovicic (1857–1936), a Croatian meteorologist. The discovery of the Moho was most important because it helped scientists discover a second layer, or mantle, inside the earth. It also helped scientists to determine more accurately where this second layer was located in relation to Earth's surface, or crust.