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Khan Academy
Khan Academy: How We Know About the Earth's Core
Find out how S-wave shadow and P-wave detection patterns give us information about the Earth's core. [5:49]
Khan Academy
Khan Academy: The Mohorovicic Seismic Discontinuity
A video lecture discussing the Mohorovicic Seismic Discontinuity which is the boundary between crust and mantle. [6:13]