Plate Tectonics Questions Medium
The theory of continental drift and the theory of plate tectonics are related concepts that explain the movement of Earth's lithospheric plates, but they differ in their scope and level of detail.
The theory of continental drift, proposed by Alfred Wegener in the early 20th century, suggests that the continents were once joined together in a single supercontinent called Pangaea and have since drifted apart to their current positions. Wegener supported this idea with evidence such as the fit of the continents, matching geological formations, and fossil distribution. However, he was unable to provide a satisfactory mechanism for the movement of the continents, which led to skepticism and limited acceptance of his theory.
On the other hand, the theory of plate tectonics, developed in the 1960s and 1970s, expanded upon Wegener's ideas and provided a comprehensive explanation for the movement of Earth's lithospheric plates. According to this theory, the Earth's lithosphere is divided into several large and small plates that float on the semi-fluid asthenosphere beneath them. These plates are in constant motion, driven by the convective currents in the underlying mantle. The boundaries between these plates are known as plate boundaries, where various geological phenomena occur, such as earthquakes, volcanic activity, and the formation of mountain ranges.
Plate tectonics incorporates and explains the mechanisms behind continental drift, as well as other geological processes like seafloor spreading and subduction. It also provides a framework to understand the distribution of earthquakes, volcanoes, and the formation of various landforms. The theory of plate tectonics has been widely accepted by the scientific community due to the abundance of evidence supporting it, including seafloor magnetic anomalies, paleomagnetic data, and the observation of plate movements using GPS technology.
In summary, while the theory of continental drift proposed the idea of continents moving over time, the theory of plate tectonics expanded upon this concept by providing a comprehensive explanation for the movement of Earth's lithospheric plates, incorporating various geological processes and mechanisms.