The map of the Earth is always changing; not only are the underlying plates moving, but the plates change in size. Also, the sea level changes over time as the temperature on Earth varies and the poles melt or freeze to varied extents, covering or exposing different amounts of crust.
The theory of plate tectonics has done for geology what Charles Darwin's theory of evolution did for biology. It provides geology with a comprehensive theory that explains "how the Earth works." The theory was formulated in the 1960s and 1970s as new information was obtained about the nature of the ocean floor, Earth's ancient magnetism, the distribution of volcanoes and earthquakes, the flow of heat from Earth's interior, and the worldwide distribution of plant and animal fossils.
No comments:
Post a Comment