Mohorovičić discontinuity

The Mohorovičić discontinuity, often called the "Moho," is a boundary inside the Earth that separates the crust from the underlying mantle. It was discovered by geophysicist Andrija Mohorovičić in 1909. This boundary marks a sudden increase in seismic wave speed, indicating a change in rock composition from the lighter, rigid crust to denser, semi-solid mantle material. The Moho varies in depth, typically about 5-70 kilometers below the surface, depending on location. It is a fundamental feature for understanding Earth's internal structure and helps explain how seismic waves travel during earthquakes.