Question

How does thickness of the earth’s crust change from the continent to ocean?

Answer 1

The thickness of the earth’s crust varies significantly from the continents to the ocean floor. On the continents, the crust is thicker, averaging about 30-35 km, and can be as thick as 70 km under major mountain ranges like the himalayas. In contrast, the oceanic crust is much thinner, averaging around 5 km in thickness. This difference occurs because the continental crust is composed largely of lighter, silica and aluminium-rich rocks (SIAL), which makes it thicker, while the oceanic crust is made mostly of heavier, silica and magnesium-rich rocks (SIMA), which is thinner and denser. Thus, the crust transitions from a thick continental crust to a thinner oceanic crust going from land to ocean floors.