Science Olympiad Dynamic Planet Practice Test

What kind of plate boundary is primarily associated with sea-floor spreading?

1. Divergent boundary

2. Convergent boundary

3. Transform boundary

4. Static boundary

The correct answer is: Divergent boundary

Sea-floor spreading is primarily associated with divergent boundaries. At these boundaries, tectonic plates move apart from each other, allowing magma from the mantle to rise and create new oceanic crust. This process occurs at mid-ocean ridges, where the tectonic plates diverge, and as the magma cools, it forms new basaltic rock along the ocean floor. As the plates separate, new material is continuously added to the edges of the plates, leading to the expansion of the ocean basin. The creation of new crust at divergent boundaries is a key component of the theory of plate tectonics and plays a significant role in shaping the geography of the ocean floor. In contrast, convergent boundaries involve the collision of tectonic plates, typically leading to the subduction of one plate beneath another and the formation of features such as trenches and mountain ranges, rather than the creation of new crust. Transform boundaries feature lateral sliding of plates against each other, which does not lead to sea-floor spreading or the formation of new oceanic crust. A static boundary implies a lack of movement, which does not apply to the dynamic processes involved in plate tectonics. Thus, the association of sea-floor spreading with divergent boundaries illustrates the fundamental geological processes shaping our planet.