Science Olympiad Dynamic Planet Practice Test

What term describes the phenomenon of oceanic crust forming along mid-ocean ridges?

1. Continental drift

2. Seafloor spreading

3. Plate tectonics

4. Subduction

The correct answer is: Seafloor spreading

The phenomenon of oceanic crust forming along mid-ocean ridges is referred to as seafloor spreading. This process occurs when tectonic plates move apart at divergent boundaries, typically located under the ocean. As the plates separate, magma from the mantle rises to fill the gap, solidifying to create new oceanic crust. Seafloor spreading is integral to our understanding of how oceans are formed and how they grow over time. It helps explain the symmetrical patterns of magnetic striping on either side of mid-ocean ridges, which confirms that new crust is continuously created as the plates move apart. Additionally, seafloor spreading is a key aspect of the theory of plate tectonics, as it demonstrates one of the processes responsible for the movement of Earth's lithospheric plates. Other terms, while related, do not specifically refer to the creation of oceanic crust at mid-ocean ridges. Continental drift pertains to the gradual movement of continents across the Earth's surface, plate tectonics is a broader theory encompassing the movement and interaction of all tectonic plates, and subduction involves one plate descending beneath another, leading to crust destruction rather than formation.