What is Moho's Discontinuity

Moho's Discontinuity, also known simply as the "Moho," is a significant boundary within the Earth's structure. It represents the transition zone between the Earth's crust and the mantle. This boundary is characterized by a distinct change in seismic wave velocities, which is how it was first identified.

1. Discovery and Significance: The Moho was discovered in 1909 by the Croatian seismologist Andrija Mohorovičić. He observed that seismic waves from earthquakes traveled at different speeds through the Earth's crust compared to the mantle, indicating a change in material properties at a certain depth. This discovery was crucial as it provided insights into the layered structure of the Earth.

2. Depth and Composition: The depth of the Moho varies depending on the location. Under continental crust, it is typically found at depths of about 30 to 50 kilometers, while under oceanic crust, it is shallower, around 5 to 10 kilometers deep. The crust above the Moho is composed of lighter, less dense rocks, while the mantle below is made of denser, ultramafic rocks.

3. Seismic Wave Behavior: The change in seismic wave velocities at the Moho is due to the difference in composition and density between the crust and the mantle. P-waves (primary waves) and S-waves (secondary waves) travel faster in the denser mantle than in the crust, which is why they speed up upon crossing the Moho.

4. Geological Implications: Understanding the Moho is essential for geologists and seismologists as it helps in studying tectonic processes, such as plate tectonics and the formation of mountains. It also aids in the exploration of natural resources, as the properties of the crust and mantle can influence the location and extraction of minerals and hydrocarbons.

In summary, Moho's Discontinuity is a crucial geological boundary that provides valuable information about the Earth's internal structure and dynamics.