Science Olympiad Dynamic Planet Practice Test

Which natural process is involved in the formation of new oceanic crust?

1. Volcanic activity

2. Weathering

3. Subduction

4. Magma erosion

The correct answer is: Volcanic activity

The formation of new oceanic crust is primarily driven by volcanic activity, specifically at mid-ocean ridges where tectonic plates diverge. As these plates separate, magma from the mantle rises to fill the gap. When this magma erupts, it solidifies to create new igneous rock, forming new oceanic crust. This process of sea-floor spreading is continuous and plays a critical role in the dynamic nature of Earth's lithosphere. While weathering pertains to the breakdown of rocks and minerals at the Earth's surface, it does not contribute to the formation of new crust. Subduction, on the other hand, involves the descent of one tectonic plate beneath another into the mantle, which results in the recycling of existing crust rather than the creation of new crust. Magma erosion is not a widely recognized geological process and does not accurately describe the mechanisms producing new oceanic crust. Thus, volcanic activity stands out as the key process in generating new oceanic crust.