Final answer:
Continental drift, proposed by Alfred Wegener in 1915, describes the gradual movement of Earth’s continents. It underpins the theory of plate tectonics, explaining Earth’s geological features and movements. The slow drift should not alarm coastal residents as it occurs over millions of years.
Step-by-step explanation:
Understanding Continental Drift
Continental drift is a theory originally proposed by Alfred Wegener in 1915. It refers to the gradual movement of Earth's continents over geological time. Wegener observed that coastlines, such as those of South America and Africa, seemed to fit together like puzzle pieces. This, along with evidence such as matching fossils and mountain ranges on continents now separated by oceans, led him to theorize that the continents had once been joined in a supercontinent called Pangaea. Although initially met with skepticism due to the lack of a mechanism explaining how continents could move, the idea of continental drift laid the groundwork for the modern understanding of plate tectonics, which describes how Earth's crust is divided into plates that float on the semi-fluid mantle, causing the continents to drift over time.
The idea of continental drift is not a cause for alarm; rather, it is a natural part of Earth's geological processes. The continents drift at a very slow rate, generally a few centimeters per year, which, over millions of years, can amount to significant movement. This drifting leads to the formation of mountains, earthquakes, and volcanic activity but does not happen suddenly or catastrophically so as to cause immediate concern for inhabitants near the coastlines.