Mohorovičić discontinuity

Immediately above the Moho, the velocities of primary seismic waves (P-waves) are consistent with those through basalt (6.7–7.2 km/s), and below they are similar to those through peridotite or dunite (7.6–8.6 km/s).

Using velocity data from the earthquake, he was able to calculate the depth of the Moho to be approximately 54 km, which was supported by subsequent seismological studies.

By observing the Moho's refractive nature and how it affects the speed of P-waves, scientists were able to theorize about the earth's composition.

[14] After initial success in establishing deep-ocean drilling, the project suffered from political and scientific opposition, mismanagement, and cost overruns, and it was cancelled in 1966.

[16] One proposal considers a rock-melting radionuclide-powered capsule with a heavy tungsten needle that can propel itself down to the Moho discontinuity and explore Earth's interior near it and in the upper mantle.

Plans called for the drill-ship JOIDES Resolution to sail from Colombo in Sri Lanka in late 2015 and to head for the Atlantis Bank, a promising location in the southwestern Indian Ocean on the Southwest Indian Ridge, to attempt to drill an initial bore hole to a depth of approximately 1.5 kilometres.

Earth's crust and mantle, Moho discontinuity between bottom of crust and solid uppermost mantle
Two paths of a P-wave, one direct and one refracted as it crosses the Moho [ 4 ]
Ordovician ophiolite in Gros Morne National Park , Newfoundland . This rock which formed the Ordovician Moho is exposed on the surface.
As shown in the figure, the Moho maintains a relatively stable average depth of 10 km under the ocean sea floor, but can vary by more than 70 km below continental land masses.