Today's continents were formed when the giant landmass Pangaea separated into smaller continents, due to plate tectonics. Pangaea was a collection of earlier continents.Continue Reading
Initially, Pangaea broke apart into two large areas, known as Gondwana and Laurasia. Gondwana was made up of what became Australia, India, South America, Africa and Antarctica while Laurasia was composed of Europe, North America and Asia. Eventually, North America split from Laurasia, and South America split from Gondwana, pushed apart by plate tectonics. India split from Gondwana and ran into Asia, creating the Himalayas. Australia and Antarctica also broke off of Gondwana.
Plate tectonics is the theory that the Earth's top layer is composed of a series of plates that move over the hotter layers below. They are pushed apart at continental ridges, like the one in the Atlantic Ocean. Fault lines and subduction zones can also affect how they move.Learn more about Homework Answers
According to National Geographic, sea floor spreading and plate tectonics indicate that the continents do move or shift, which supports continental drift theory. Fossils of the Mesosaurus, an ancient freshwater reptile found in the southern parts of South America and Africa, also indicate that the two continents could have once been one solid continent that drifted apart, since the reptile could not have swum across the ocean.Full Answer >
Italy is shaped like a boot because the landmass gradually formed as Africa moved north creating the European tectonic plate, the Mediterranean Basin and several mountain ranges. Eventually the Apennines Mountains grew that run down the spine of Italy to Sicily, forming a boot-like shape.Full Answer >
Venice is sinking because the Adriatic plate underneath the city is subducting beneath the Apennines Mountains due to plate tectonics and the slow compaction of the sediments that support the city. One or both of these processes is also causing a slight tilt of the city to the East. Historically, pumping groundwater from beneath the city also contributed to the sinking, but such pumping was stopped.Full Answer >
According to About.com, the Earth creates mountains through plate tectonics, where its crust is broken into plates constantly in motion, causing stress and uplifting in order to grow mountains. While growth is slow due to these forces, it does happen.Full Answer >