Science Olympiad Dynamic Planet Practice Test

What is the average thickness of the oceanic crust?

1. 30-50 kilometers

2. 5-10 kilometers

3. 20-30 kilometers

4. 15-25 kilometers

The correct answer is: 5-10 kilometers

The average thickness of the oceanic crust is around 5 to 10 kilometers. This thin crust forms at mid-ocean ridges where tectonic plates diverge and is primarily composed of basaltic rocks. Oceanic crust is significantly thinner than continental crust, which can exceed 30 kilometers in thickness. The oceanic crust is created by the upwelling of magma from the mantle that solidifies at the seafloor. Understanding the characteristics of oceanic crust is crucial for studying plate tectonics, as its formation and recycling into the mantle at subduction zones play a vital role in the Earth’s geological processes.