Tectonic plate in the context of Scientific theory

Anydros (Greek: Άνυδρος) is an uninhabited Greek islet in the municipality of Santorini, which is a group of islands in the Cyclades. It is north of the island Anafi, and southwest of Amorgos. It is sometimes called Greek: Αμοργοπούλα, romanized: Amorgopoúla. The island hosts a seismometer, part of the Greek national network, installed in 2025. An earthquake fault located near Anydros was the source of the 1956 Amorgos earthquake that registered 7.6 on the Richter scale and caused widespread damage on Amorgos and the island of Santorini, where dozens died.A second 7.5 quake and a 30-meter tsunami followed.

There were hundreds of minor earthquakes of up to magnitude 5 in an area around Anydros at the beginning of February 2025, causing concern in Santorini and causing more than half the population to leave the island. The seismic activity was attributed to tectonic plate movements rather than volcanism, and it was thought that it could last weeks.

The Alps (/ælps/) are some of the highest and most extensive mountain ranges in Europe, stretching approximately 1,200 km (750 mi) across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia.

The Alpine arch extends from Nice on the western Mediterranean to Trieste on the Adriatic and Vienna at the beginning of the Pannonian Basin. The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided. Extreme shortening caused by the event resulted in marine sedimentary rocks rising by thrusting and folding into high mountain peaks such as Mont Blanc and the Matterhorn.

Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspots. The dispersal of hydrothermal fluids throughout the global ocean at active vent sites creates hydrothermal plumes. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents.

Hydrothermal vents exist because the Earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, they may form features called black smokers or white smokers, which deliver a wide range of elements to the world's oceans, thus contributing to global marine biogeochemistry. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. Chemosynthetic bacteria and archaea found around hydrothermal vents form the base of the food chain, supporting diverse organisms including giant tube worms, clams, limpets, and shrimp. Active hydrothermal vents are thought to exist on Jupiter's moon Europa and Saturn's moon Enceladus, and it is speculated that ancient hydrothermal vents once existed on Mars.

A mountain is an elevated portion of the surface of a planet, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 600 metres (2,000 ft) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges.

Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers.

The Red Sea Rift is a mid-ocean ridge between two tectonic plates, the African plate and the Arabian plate. It extends from the Dead Sea Transform fault system, and ends at an intersection with the Aden Ridge and the East African Rift, forming the Afar triple junction in the Afar Depression of the Horn of Africa.

The Red Sea Rift was formed by the divergence between the African and Arabian plates. The rift transitioned from a continental rift to an oceanic rift. Magnetic anomalies suggest that the spreading rate on either side of the Red Sea is about 1 cm/year. The African plate has a rotation rate of 0.9270 degrees/Ma (million years), while the Arabian plate has a rotation rate of 1.1616 degrees/Ma.

A massif (/mæˈsiːf, ˈmæsɪf/) is a principal mountain mass, such as a compact portion of a mountain range, containing one or more summits (e.g. France's Massif Central). In mountaineering literature, massif is frequently used to denote the main mass of an individual mountain.

As a purely scientific term in geology, however, a "massif" is separately and more specifically defined as a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. A massif is a smaller structural unit than a tectonic plate and is considered the fourth-largest driving force in geomorphology.

In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems.

Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates.

A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting plate than the trench. The oceanic plate is saturated with water, mostly in the form of hydrous minerals such as micas, amphiboles, and serpentines. As the oceanic plate is subducted, it is subjected to increasing pressure and temperature with increasing depth. The heat and pressure break down the hydrous minerals in the plate, releasing water into the overlying mantle. Volatiles such as water drastically lower the melting point of the mantle, causing some of the mantle to melt and form magma at depth under the overriding plate. The magma ascends to form an arc of volcanoes parallel to the subduction zone.

Volcanic arcs are distinct from volcanic chains formed over hotspots in the middle of a tectonic plate. Volcanoes often form one after another as the plate moves over the hotspot, and so the volcanoes progress in age from one end of the chain to the other. The Hawaiian Islands form a typical hotspot chain, with the older islands to the northwest and Hawaii Island itself, which is just 400,000 years old, at the southeast end of the chain over the hotspot. Volcanic arcs do not generally exhibit such a simple age-pattern.

Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year.

Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own weight.

The Aegean Sea plate (also called the Hellenic plate or Aegean plate) is a small tectonic plate located in the Eastern Mediterranean under Southern Greece and western Turkey. Its southern edge is the Hellenic subduction zone south of Crete, where the African plate is being swept under the Aegean Sea plate. Its northern margin is a divergent boundary with the Eurasian plate.

The seafloor in this region is about 350 m below sea level, while the adjacent Black Sea and Mediterranean Sea are 1300–1500 m deep. For this reason it is considered a high plateau between the seas. Evidence suggests the Aegean plate contains thinned continental crust, rather than oceanic crust. Since its creation the crust has been thinned through various processes, including post-orogenic collapse and crustal extension. This extension is responsible for the formation of the Gulf of Corinth.

The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid-Atlantic Ridge.

The easterly edge is a divergent boundary with the African plate; the southerly edge is a complex boundary with the Antarctic plate, the Scotia plate, and the Sandwich Plate; the westerly edge is a convergent boundary with the subducting Nazca plate; and the northerly edge is a boundary with the Caribbean plate and the oceanic crust of the North American plate. At the Chile triple junction, near the west coast of the Taitao–Tres Montes Peninsula, an oceanic ridge known as the Chile Rise is actively subducting under the South American plate.

Tectonics (from Ancient Greek τεκτονικός tektonikós 'pertaining to building' via Latin tectonicus) are the processes that result in the structure and properties of Earth's crust and its evolution through time. The field of planetary tectonics extends the concept to other planets and moons.

These processes include those of mountain-building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute Earth's outer shell interact with each other. Principles of tectonics also provide a framework for understanding the earthquake and volcanic belts that directly affect much of the global population.

Strictly speaking, geo-thermal necessarily refers to Earth, but the concept may be applied to other planets. In SI units, the geothermal gradient is expressed in degree celsius per kilometre (°C/km), kelvin per kilometre (K/km), or millikelvin per metre (mK/m); these are all equivalent.

Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (M_w) that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes.

The thrust faults responsible for megathrust earthquakes often lie at the bottom of oceanic trenches; in such cases, the earthquakes can abruptly displace the sea floor over a large area. As a result, megathrust earthquakes often generate tsunamis that are considerably more destructive than the earthquakes themselves. Teletsunamis can cross ocean basins to devastate areas far from the original earthquake.

The Philippine Sea plate or the Philippine plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part of the Philippine Mobile Belt, which is geologically and tectonically separate from the Philippine Sea plate.

The plate is bordered mostly by convergent boundaries: To the north, the Philippine Sea plate meets the Okhotsk microplate at the Nankai Trough. The Philippine Sea plate, the Amurian plate, and the Okhotsk plate meet near Mount Fuji in Japan. The thickened crust of the Izu–Bonin–Mariana arc colliding with Japan constitutes the Izu Collision Zone. The east of the plate includes the Izu–Ogasawara (Bonin) and the Mariana Islands, forming the Izu–Bonin–Mariana Arc system. There is also a divergent boundary between the Philippine Sea plate and the small Mariana plate which carries the Mariana Islands. To the east, the Pacific plate subducts beneath the Philippine Sea plate at the Izu–Ogasawara Trench. To the south, the Philippine Sea plate is bounded by the Caroline plate and Bird's Head plate. To the west, the Philippine Sea plate subducts under the Philippine Mobile Belt at the Philippine Trench and the East Luzon Trench. (The adjacent rendition of Prof. Peter Bird's map is inaccurate in this respect.) To the northwest, the Philippine Sea plate meets Taiwan and the Nansei islands on the Okinawa plate, and southern Japan on the Amurian plate.It also meets the Yangtze plate due northwest.

The Aden Ridge is a part of an active oblique rift system located in the Gulf of Aden, between Somalia and the Arabian Peninsula to the north. The rift system marks the divergent boundary between the Somali and Arabian tectonic plates, extending from the Owen transform fault in the Arabian Sea to the Afar triple junction or Afar Plume beneath the Gulf of Tadjoura in Djibouti.

The Gulf of Aden is divided east to west into three distinct regions by large-scale discontinuities, the Socotra, Alula Fartak, and Shukra-El Sheik transform faults. Located in the central region, bounded by the Alula Fartak fault and Shukra-El Sheik fault, is the Aden spreading ridge. The Aden Ridge connects to the Sheba Ridge in the eastern region and to the Tadjoura Ridge in the western region. Due to oblique nature of the Aden Ridge, it is highly segmented. Along the ridge there are seven transform faults that offset it to the north.