Plate tectonics are parts of the Earth's lithosphere that are divided into seven major plates and many less major ones. The major plates are the Pacific plate, North American plate, South American Plate, African Plate, Antarctica Plate, Indian-Australian Plate, and Eurasian Plate. A scientist named Alfred Wegener proposed the idea of a supercontinent by the name of Pangea. His reasoning for the change of the landmasses had been his theory of continental drift, the idea that the continents, drifted. Although scientists approved of his supercontinent idea, they disliked his reasoning for it. From the 1960s to the 1970s, scientists made many important discoveries about the oceans crust, such as paleomagnetism as scientists studied the earth's magnetic fields. The next theory about why the continents moved was the plate tectonics theory. This theory talked about earth's lithosphere being divided into a number of crustal plates that move independently and collide, slide past, slide under, or slide over with adjacent plates. .
There are many problems caused by plate tectonics: earthquakes, tsunamis, and volcanoes. Earthquakes are caused by two of the plates sliding past each other, causing the earth's crust around it to shake. The radius of the earthquake depends on how strong it was. Tsunamis are a form of an earthquake aftermath. After the ground quits shaking, it can produce large waves and rise and travel at fast rates. This also depends on how strong the earthquake is. Volcanoes are created when two tectonic plates collide in a convergent boundary. Volcanoes, though not being an immediate threat, can be very dangerous over time. .
Earthquakes impacts people, and environments greatly. A very strong earthquake can cause damage to houses, roads, buildings of importance, and death to people. Damage to a city can take a very long time to rebuild. Rebuilding a city after an earthquake can also cost a lot of money.