Science Olympiad Dynamic Planet Practice Test

What is the term for an undersea mountain chain where new ocean floor is produced?

1. Mid-ocean ridge

2. Continental slope

3. Ocean trench

4. Coral reef

The correct answer is: Mid-ocean ridge

The term for an undersea mountain chain where new ocean floor is produced is the mid-ocean ridge. This geological feature is a pivotal part of the process known as seafloor spreading, which occurs at divergent tectonic plate boundaries. As tectonic plates move apart, magma rises from the mantle to fill the gap. When this magma cools, it solidifies to form new oceanic crust. Mid-ocean ridges are characterized by their distinctive elongated shape and often have volcanic activity associated with them, as the formation of new crust is a volcanic process. The continuous nature of these ridges, alongside their comprehensive underwater network, indicates they play a vital role in the Earth's geology and oceanic system. In contrast, other options like the continental slope refer to the steep transition between the continental shelf and the deep ocean floor, ocean trenches are the deepest parts of the oceans formed by subduction zones where one tectonic plate moves under another, and coral reefs are marine ecosystems built from calcium carbonate structures created by coral polyps. None of these terms relate to the process of creating new ocean floor, making mid-ocean ridge the correct answer.