The earth is theoretically split into many layers. There is the core, which forms the center of the earth. The core itself is divided into inner core and outer core. Then there is the mantle and finally the crust. The crust is atop which we live. The topmost layer of the crust is the surface of the earth. While the inner and outer cores are in liquid state, the mantle has a semi solid state. There are molten rocks or magma. Atop this magma is the crust. The crust of the earth is made up of many layers and there are large pieces of such layers which are known as plates.
Plate Tectonics: Definition
The earth’s crust is made up of large plates that coexist and float on the magma or molten rock in the mantle. The plates are made of solid rock. There are several such large plates that form the earth’s crust. These plates are also known as tectonic plates. These tectonic plates float on the molten rock and thus move, at times away from other plates, at times towards other plates and at times along or against other plates.
The larger plates are known as major plates which can be larger than the continents of present day. The major plates in the world are the Pacific Plate, North American Plate, Eurasian Plate, African Plate, Antarctic Plate, Indo-Australian Plate and South American Plate. The Indo-Australian Plate is essentially two different major plates, namely the Australian Plate and Indian Plate.
The list of minor plates includes Somali Plate, Philippine Sea Plate, Arabian Plate, Caribbean Plate, Caroline Plate, Scotia Plate, Burma Plate and New Hebrides Plate. There are many other smaller plates known as microplates, such as African Plate, Madagascar Plate, Victoria Plate, Panama Plate, Aegean Sea Plate, Iranian Plate, Okinawa Plate, Timor Plate, Sri Lanka Plate, Greenland Plate, Easter Plate, Solomon Sea Plate and North Andes Plate among others.
Plate Tectonics Movements
If a plate runs into another plate, then one plate may slide under another plate. This will cause earthquakes. If a plate collides with another plate and both plates rise up then there will be a formation of hills or mountains and corresponding valleys or gorges, also causing earthquakes in the process. If two plates move away from one another then molten rock will rise in the place and form a new layer, plate or crust as the molten rock cools down. There could be a volcanic eruption in the process. If two plates just brush against one another along the fault lines then there would be seismic activity but new landforms may not be formed.