Mohorovičić discontinuity

The Mohorovičić discontinuity ( MOH-hə-ROH-vih-chitch; Croatian: [moxorôʋiːtʃitɕ]), usually called the Moho discontinuity, Moho boundary, or just Moho, is the boundary between the crust and the mantle of Earth. It is defined by the distinct change in velocity of seismic waves as they pass through changing densities of rock.