what are tectonic plates?

A tectonic plate (also called lithospheric plate) is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere. Plate size can vary greatly, from a few hundred to thousands of kilometers across; the Pacific and Antarctic Plates are among the largest. Plate thickness also varies greatly, ranging from less than 15 km for young oceanic lithosphere to about 200 km or more for ancient continental lithosphere (for example, the interior parts of North and South America).

Plate tectonics(from theLate Latintectonicus, from theGreek:τεκτονικός"pertaining to building")^[1]is ascientific theorythat describes the large-scale motions ofEarth'slithosphere.

Atectonic plate(also called lithospheric plate) is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere. Plate size can vary greatly, from a few hundred to thousands of kilometers across; the Pacific and Antarctic Plates are among the largest. Plate thickness also varies greatly, ranging from less than 15 km for young oceanic lithosphere to about 200 km or more for ancient continental lithosphere (for example, the interior parts ofNorth and SouthAmerica).How do these massive slabs ofsolid rockfloat despite their tremendous weight? The answer lies in the composition of the rocks. Continental crust is composed of granitic rocks which are made up of relatively lightweight minerals such as quartz and feldspar. By contrast, oceanic crust is composed of basaltic rocks, which are much denser and heavier. The variations inplate thicknessare nature's way of partly compensating for the imbalance in the weight and density of the two types of crust. Because continental rocks are much lighter, the crust under the continents is much thicker (as much as 100 km) whereas the crust under the oceans is generally only about 5 km thick. Like icebergs, only the tips of which are visible above water, continents have deep "roots" to support their elevations.Most of the boundaries between individual plates cannot be seen, because they are hidden beneath the oceans. Yet oceanic plate boundaries can be mapped accurately from outer space by measurements from GEOSAT satellites. Earthquake and volcanic activity is concentrated near these boundaries. Tectonic plates probably developed very early in the Earth's 4.6-billion-year history, and they have been drifting about on the surface ever since-like slow-movingbumper carsrepeatedly clustering together and then separating.Like many features on the Earth's surface, plates change over time. Those composed partly or entirely of oceanic lithosphere can sink under another plate, usually a lighter, mostly continental plate, and eventually disappear completely. This process is happening now off the coast of Oregon and Washington. The smallJuan de FucaPlate, a remnant of the formerly much larger oceanic Farallon Plate, will someday be entirely consumed as it continues to sink beneath the North American Plate.

Tectonic plates arelarge platesof rock that make up the foundation of the Earth's crust and the shape of the continents. The tectonic plates comprise the bottom of the crust and the top of theEarth's mantle. There are ten major plates on Earth and many more minor ones. They float on a plastic-like part of the Earth's mantle called the asthenosphere. The plates are most famously known for being the source ofearthquakes.

The tectonic plates are about 100 km (60 miles) in thickness, with continental plates tending to be thicker than oceanic ones. The composure of the two types of plate is also quite different. Oceanic plates consist of thicker basaltic rocks, compressed by the pressure of kilometers of water. Contintental plates have a lower average density, containing granitic rocks with a heavy composition ofaluminumand silica.

The mantle underneath the tectonic plates is constantly recirculating, causing the plates to float around slowly in a process called tectonic drift. This process was described well by thetheoryofplate tectonics, which solved several scientific dilemmas about the distribution of species when it was introduced. When plates push up against each other, they create mountain ranges and volcanoes. Mt. Everest was created in this way.

Because the plates are so large, each wraps over a considerable portion of the Earth's surface, making them curved. This is a different shape than the flatness the word "plate" suggests.

Over time, plate tectonics has caused the world's continents to be reshaped. Every continent on Earth was once part of an ancientsupercontinentknown as Pangaea, and Antarctica was once located in a temperate climate. Marine fossils can be found on the peaks of the world's tallest mountains. The tectonic plates continue to move slowly, but it is unlikely that their movement will cause the world's face to change more rapidly than the growing technological influence of mankind will. One day the plates' great momentum and pressure might even be used as a source of geological energy.

Tectonic plates are the fragmented parts of the lithosphere formed by the breaking of the crustal block due to the rising convention current from the mantle.

The earth's lithosphere is composed of large semi rigid plates that float on the underlying molten core-explains natural phenomena, including earthquakes and tsunamis caused by movement of one plate on another; volcanoes, which occur at sites where the molten core escapes between plates; and the distribution of plant and animal species that relates to the position of large continental land masses in earlier geological eras. These plates are called Tectonic Plates.

Hope this helps:)