Science Olympiad Dynamic Planet Practice Test

Which hypothesis suggests that continents slowly move across Earth's surface?

1. Plate tectonics

2. Continental Drift

3. Sea-floor spreading

4. Geocentric theory

The correct answer is: Continental Drift

The hypothesis that suggests continents slowly move across Earth's surface is known as continental drift. This theory, first proposed by Alfred Wegener in the early 20th century, posits that continents were once part of a single landmass (Pangaea) that gradually broke apart and drifted to their current locations. Wegener's idea was based on various lines of evidence, including the fit of the continents, fossil similarities across continents, and geological formations that matched across oceans. While plate tectonics encompasses the broader theory explaining the movements of the Earth's lithosphere, continental drift specifically focuses on the shifting of continents. Sea-floor spreading describes the process of new oceanic crust being formed at mid-ocean ridges and does not directly address continental movement. The geocentric theory is an outdated astronomical model that places Earth at the center of the universe and has no relevance to continental movement. Thus, the idea of continental drift directly relates to the gradual movement of the Earth's continents over geological time, making it the correct answer.