Volcanism

The decrease of pressure in the rising mantle rock leads to adiabatic expansion and the partial melting of the rock, causing volcanism and creating new oceanic crust.

Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption.

Scoria (pl. scoriae), also called volcanic cinder, is a pyroclastic, highly vesicular, dark-colored volcanic rock formed by ejection from a volcano as a molten blob and cooled in the air to form discrete grains called clasts.

Stratovolcano, Compound Guatemala, 15.04°N / -91.9°W

Shield, Stratovolcano(es), Pyroclastic cone(s) Kyushu (Japan), 31.93°N / 130.86°E

Shield, Pyroclastic cone(s), Lava dome(s) Antarctica, -77.52°S / 168.55°E

Stratovolcano, Lava dome(s)

Lava dome, Tuff cone Mindanao (Philippines), 7.88°N / 125.07°E

Instead, archipelagic aprons most likely formed from debris avalanches and pyroclastic flows.

Citlaltépetl (from Náhuatl citlal(in) = star, and tepētl = mountain), otherwise known as Pico de Orizaba, is an active volcano and the highest volcano in North America, as well as the highest mountain in Mexico and third highest peak in North America, after Denali of the United States and Mount Loga

Momotombo is a stratovolcano in Nicaragua, located near the city of León

The Barrier is a lava dam retaining the Garibaldi Lake system in southwestern British Columbia, Canada

Stromboli ( STROM-bə-lee, Italian: [ˈstromboli]; Sicilian: Struògnuli [ˈʂː(ɽ)wɔɲɲʊlɪ]) is an island in the Tyrrhenian Sea, off the north coast of Sicily, containing Mount Stromboli, one of the four active volcanoes in Italy

Krakatoa (), also transcribed Krakatau (), is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung

Mount St. Helens (known as Lawetlat'la to the local Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States

Mauna Loa (, Hawaiian: [ˈmɐwnə ˈlowə]; lit. 'Long Mountain') is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean

Mount Rinjani (Indonesian: Gunung Rinjani; Sasak: ᬕᬸᬦ᭄ᬗᬸᬂ᭞ᬭᬶᬦ᭄ᬚᬦᬶ, romanized: gunong rinjani) is an active stratovolcano situated in regencial North Lombok of West Nusa Tenggara province on the Indonesian island of Lombok

A mud volcano or mud dome is a landform created by the eruption of mud or slurries, water and gases

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

In geology and geomorphology, an erosion surface is a surface of rock or regolith that was formed by erosion and not by construction (e.g. lava flows, sediment deposition) nor fault displacement

A caldera ( kawl-DERR-ə, kal-) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption

A lava tube, more rarely called a pyroduct or lava tunnel, is a natural roofed conduit along which molten lava flows from a volcanic vent

In volcanology, a lava dome is a circular, mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano

A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano

A cinder cone or scoria cone is a steep, conical landform of loose pyroclastic fragments, such as volcanic ash, clinkers, or scoria, that has been built around a volcanic vent

A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground

A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra

A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma)

A tuya is a flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet

A volcanic crater is an approximately circular depression in the ground caused by volcanic activity

A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe associated with a gaseous explosion

A volcanic plateau is a plateau produced by volcanic activity

A volcanic field is an area of Earth's crust that is prone to localized volcanic activity

Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt

A supervolcano is a volcano that has had an eruption with a volcanic explosivity index (VEI) of 8, the largest recorded value on the index

A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons

A hornito is a conical, or pipe-like, structure built up by lava spattering or being ejected through an opening in the crust of a lava flow

Dimmuborgir (dimmu "dark", borgir "cities" or "forts", "castles"; pronounced [ˈtɪmːʏˌpɔrcɪr̥]) is a large area of unusually shaped lava fields east of Mývatn in Iceland

The Salvation Islands (French: Îles du Salut, so called because missionaries went there to escape plague on the mainland), sometimes mistakenly called the Safety Islands, are a group of small islands of volcanic origin about 11 kilometres (6 nautical miles) off the coast of French Guiana, 14 kilomet

In marine geology, a guyot (), also called a tablemount, is an isolated underwater volcanic mountain (seamount) with a flat top more than 200 m (660 ft) below the surface of the sea

The Pitcairn Islands ( PIT-kairn; Pitkern: Pitkern Ailen), officially Pitcairn, Henderson, Ducie and Oeno Islands, are a group of four volcanic islands in the southern Pacific Ocean that form the sole British Overseas Territory in the Pacific Ocean

The Kuril Islands or Kurile Islands are a volcanic archipelago administered as part of Sakhalin Oblast in the Russian Far East

The Prince Edward Islands are two small uninhabited subantarctic volcanic islands in the southern Indian Ocean that are administered by South Africa

The Hawaiian Islands (Hawaiian: Mokupuni Hawaiʻi) are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some 1,500 miles (2,400 kilometers) from the island of Hawaiʻi in the south to northernmost Kure Atoll

The Mariana Islands ( MARR-ee-AH-nə; Chamorro: Manislan Mariånas), also simply the Marianas, are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the north-western Pacific Ocean, between the 12th and 21st parallels north an

The Comoro Islands are a group of volcanic islands in the Mozambique Channel, an arm of the Indian Ocean lying between Madagascar and the African mainland

The Louisiade Archipelago is a string of ten larger volcanic islands frequently fringed by coral reefs, and 90 smaller coral islands in Papua New Guinea

Rocas Alijos, or Escollos Alijos (English: Alijos Rocks) are a series of tiny, steep, uninhabited, and barren volcanic islets or above-water (as well as below-water) rocks in the Pacific Ocean at 24°57′31″N 115°44′59″W. They are part of Comondú municipality of the Mexican state of Baja California Su

Christiana (Greek: Χριστιανά) is a group of three volcanic Greek islands in the Cyclades, in the Aegean Sea

Meola Reef, officlally Te Tokaroa Reef ('toka'='rock', 'roa'='long'), is a lava flow forming a reef peninsula across part of Auckland's Waitemata Harbour, New Zealand

The Galite Islands (Tunisian Arabic: جالطة Jalita, French: La Galite, Italian: La Galita) are a rocky group of islands of volcanic origin that belong to Bizerte Governorate, northern Tunisia

Supply Reef is a submerged circular reef of volcanic origin in the Northern Mariana Islands chain, about 10 kilometres (6 mi) NW of the Maug Islands

The Rotuma Group is a group of volcanic islands, with Rotuma Island being the main island, located at 12°35′S 177°10′E, approximately 465 km north of Fiji

The Insular Islands were an extended chain of volcanic islands forming an arc in what is now the Pacific Ocean during the Paleozoic and Mesozoic eras

Basalt (UK: BAH-salt); US: buh-SALT) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon

Andesite () is a volcanic rock of intermediate composition

Rhyolite ( RY-ə-lyte) is the most silica-rich of volcanic rocks

Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides

The Minoan eruption was a catastrophic volcanic eruption that devastated the Aegean island of Thera (also called Santorini) circa 1600 BC. It destroyed the Minoan settlement at Akrotiri, as well as communities and agricultural areas on nearby islands and the coast of Crete with subsequent earthquakes and tsunamis.

The Toba eruption (also called the Toba supereruption and the Youngest Toba eruption) was a large eruption that occurred around 74,000 years ago, during the Late Pleistocene, at the site of present-day Lake Toba, in Sumatra, Indonesia.

Between March and June 2010 a series of volcanic events at Eyjafjallajökull in Iceland caused enormous disruption to air travel across Western Europe.

The 1991 Eruption of Mount Unzen (Japanese: 1991年の雲仙岳噴火) was a natural disaster caused by the eruption of Mount Unzen in Nagasaki Prefecture, Japan.

In December 2021, an eruption began on Hunga Tonga-Hunga Haʻapai, a submarine volcano in the Tongan archipelago in the southern Pacific Ocean.

The volcanic winter was caused by at least three eruptions of uncertain origin, with several possible locations proposed in various continents.

The Line Islands, all of which were formed by volcanic activity, are one of the longest island chains in the world, stretching 2,350 km (1,460 mi) from northwest to southeast

The islets are of volcanic origin, they were formed when the Mombacho volcano blew much of its cone into the lake thousands of years ago, thereby creating the archipelago

It was created around 3,000 years ago, as a result of the explosion of the Hakone volcano.

Popocatépetl (UK: POP-ə-KAT-ə-pet-əl, -⁠kat-ə-PET-əl, US: POHP-, Spanish: [popokaˈtepetl] ; Nahuatl languages: Popōcatepētl [popoːkaˈtepeːt͡ɬ] ) is an active stratovolcano located in the states of Puebla, Morelos, and Mexico in central Mexico.

The island is entirely volcanic.

Rincón de la Vieja is an active andesitic complex volcano in north-western Costa Rica, about 23 km (14 mi) from Liberia, in the province of Guanacaste.

Menengai Crater is a massive shield volcano with one of the biggest calderas in the world, in the Great Rift Valley, Kenya.

Mount Hibok-Hibok (also known as Catarman Volcano) is a stratovolcano on Camiguin Island in the Philippines.

Misti is a volcano in the southern Peruvian Andes, rising above Arequipa, Peru's second-largest city.

Cosigüina (also spelt Cosegüina) is a stratovolcano located in the western part of Nicaragua.

Santa María Volcano is a large active volcano in the western highlands of Guatemala, in the Quetzaltenango Department near the city of Quetzaltenango.

Mount Iraya, is an active stratovolcano on Batan Island, and is the highest point in the province of Batanes, Philippines.

South Island, or Hohnel Island (named after Ludwig von Höhnel who helped with Teleki's expedition), is a fissure-formed volcanic island and the largest one out of 3 other major islands in Lake Turkana, Kenya.

It is the largest island of a small, circular archipelago formed by the Santorini caldera.

Kīlauea (US: KIL-ə-WAY-ə, Hawaiian: [kiːlɐwˈwɛjə]) is an active shield volcano in the Hawaiian Islands, located along the southeastern shore of Hawaii Island.

Laki (Icelandic pronunciation: [ˈlaːcɪ] ) or Lakagígar ([ˈlaːkaˌciːɣar̥], Craters of Laki) is a volcanic fissure in the western part of Vatnajökull National Park, Iceland, not far from the volcanic fissure of Eldgjá and the small village of Kirkjubæjarklaustur.

The Chaîne des Puys (French: [ʃɛːn de pɥi]; lit. 'Chain of the Puys') is a north-south oriented volcanic field, about 40 kilometres (25 mi) long, comprising 48 cinder cones, eight lava domes, and 15 maars and explosion craters, in the Massif Central of France.

Crater Lake (Klamath: Giiwas) is a volcanic crater lake in south-central Oregon in the Western United States.

Sierra Negra (Spanish: Black Mountain) is a large shield volcano at the southeastern end of Isabela Island in the Galapagos that rises to an altitude of 1124m.

Torfajökull (Icelandic for "Torfi's glacier"; Icelandic pronunciation: [ˈtʰɔrvaˌjœːkʏtl̥] ) is a rhyolitic stratovolcano, with a large caldera (central volcano) capped by a glacier of the same name and associated with a complex of subglacial volcanoes.

The Galápagos Islands (Spanish: Islas Galápagos) are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, 485 nautical miles (898 km; 558 mi) west of the mainland of South America.

The islands are part of a volcanic arc, the Sunda Arc, formed by subduction along the Sunda Trench in the Java Sea.

The McDonald Islands are the emergent peaks of submarine volcanoes and are Australian external territory.

Discovered in the mid-19th century, the territory is a group of sub-Antarctic volcanic islands that lie on the Kerguelen Plateau.

Situated 670 km (362 nmi; 416 mi) off the coast of Chile, they are composed of three main volcanic islands: Robinson Crusoe, Alejandro Selkirk, and Santa Clara.

The Antipodes Islands (Māori: Moutere Mahue, lit. 'Abandoned Island') are inhospitable and uninhabited volcanic islands in subantarctic waters to the south of - and territorially part of - New Zealand.

They cover an area of 27.8 km2 or 10.7 sq mi, and are made up of the Mangareva Islands, a group of high islands remnants of a caldera along with islets on the surrounding fringing reef, and the uninhabited Temoe atoll, which is located 45 km (28 mi) south-east of the Mangareva Islands.

Surtsey ("Surtr's island" in Icelandic, Icelandic pronunciation: [ˈsʏr̥(t)sˌeiː] ) is an uninhabited volcanic island located in the Vestmannaeyjar archipelago off the southern coast of Iceland.

The islands are eroded volcanic tuff rings, and consist of a small northern pair on Upolu's barrier reef, and a larger southern pair outside it.

The islands’ origins are volcanic.

The Krakatoa archipelago is a small uninhabited archipelago of volcanic islands formed by the Krakatoa stratovolcano located in the Sunda Strait, nestled between the much larger islands of Java and Sumatra.

Geological studies indicate the rock is the exposed core of an ancient volcano.

A kīpuka is an area of land surrounded by one or more younger lava flows.

Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 100-4,000 m (330-13,120 ft) in height.

Geologically, they are the oldest in the Hawaiian-Emperor seamount chain, shaped by volcanic activity and erosion over millions of years.

Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years.

Ash from a Yellowstone hotspot eruption 10-12 million years ago created these fossilized bone beds.

A fissure vent, also known as a volcanic fissure, eruption fissure or simply a fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity.

A somma volcano, also known as a sommian, is a volcanic caldera that has been partially filled by a new central cone.

In geology, a resurgent dome is a dome formed by swelling or rising of a caldera floor due to movement in the magma chamber beneath it.

A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock.

In volcanology, a pyroclastic shield or ignimbrite shield is an uncommon type of shield volcano.

A rootless cone, also formerly called a pseudocrater, is a volcanic landform which resembles a true volcanic crater, but differs in that it is not an actual vent from which lava has erupted.

A lava spine (or lava spire) is a vertical growth of solid lava that is forced from a volcanic vent.

Geologically, a volcanic island is an island of volcanic origin.

A subglacial mound is a type of subglacial volcano formed when lava erupts beneath a thick glacier or ice sheet.

The Lesser Antilles are mostly young volcanic islands created by the Lesser Antilles subduction zone.

Altogether, there are about 90 islets and reefs, volcanic rocks formed in the Cenozoic era, more specifically 4.6 to 2.5 million years ago.

The archipelago represents the remnants of a long-extinct ring volcano rising from a seabed plateau approximately 40 metres (130 ft) below sea level.

The Chagos group is a combination of different coralline rock structures topping a submarine ridge running southwards across the centre of the Indian Ocean, formed by volcanoes above the Réunion hotspot.

The Poor Knights Islands are the eroded remnants of a 4-million-year-old rhyolitic volcano that is estimated to have been 1,000 metres (3,300 ft) tall and 25 kilometres (16 mi) in diameter.

All the islands are of volcanic origin.

Mokohinau formed between 10 and 8.5 million years ago, as a part of the Coromandel Volcanic Zone, which has since moved southwards to form the modern Taupō Volcanic Zone.

Basilan, Jolo, Tawi-Tawi and other islands in the group are extinct volcanic cones rising from the southernmost ridge.

Marotiri, with an area of 0,043 km2, is a group of four uninhabited volcanic rocks protruding from the sea (and several submerged rocks), forming the southeastern end of the Austral Islands of French Polynesia.

The space between the two islets is the old volcanic crater formed of tuff rock and is approximately 20 metres (66 ft) deep.

The islands' physical characteristics are the consequences of mountain-forming and volcanic forces that occurred between 60 to 70 mya, typical of many of the islands of Macaronesia.

Dollabarat Reef is one of the higher parts of the Formigas Bank, a seamount with similar volcanic origins as the Azores islands.

Diamond Rock (French: Rocher du Diamant) is a 175-meter-high (574-foot) basalt island located south of "Grande Anse du Diamant" before arriving from the south at Fort-de-France, the main port of the Caribbean island of Martinique.

It forms a 100 km (62 mi)-long volcanic field in an elongated northwest-southeast direction.

The Marquesas Islands ( mar-KAY-səss; French: Îles Marquises or Archipel des Marquises or Marquises [maʁkiz]; Marquesan: Te Henua ʻEnana (North Marquesan) and Te Fenua ʻEnata (South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in the southern Pacific Ocean.

The islands combine to total 813 square kilometers (314 sq mi), with many of the islands being actively volcanic with fertile soil and mountains.

The fossil beds were laid down in a lake roughly 15-million-years ago, when a drainage basin was dammed by the flood basalts of the Columbia River Plateau.

Oceanic plateaus produced by large igneous provinces are often associated with hotspots, mantle plumes, and volcanic islands, such as Iceland, Hawaii, Cape Verde, and Kerguelen.

Fajã (Portuguese pronunciation: [fɐˈʒɐ̃], of unknown etymology) is a Portuguese term of obscure origin used to describe supratidal talus at the foot of coastal cliffs, caused by landslides or lava flows.

Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, and erosion by water and glaciers.

A laccolith forms when magma (molten rock) rising through the Earth's crust begins to spread out horizontally, prying apart the host rock strata.

Such mountain systems have a complex structure, which is usually the result of folding and faulting accompanied by volcanic activity.

While most of the northern Lau Group are high islands of volcanic origin, those of the south are mostly carbonate low islands.

The landscape, dominated by smooth bedrock, bears witness to volcanic activity and subsequent wear due to the Ice Age.

The atoll is believed to be volcanic in origin being on top of one of the Tasmantid Seamounts.

Formation occurs at depths between 150 and 450 kilometres (93 and 280 mi), potentially from anomalously enriched exotic mantle compositions, and they are erupted rapidly and violently, often with considerable carbon dioxide and other volatile components.

Novarupta was formed in 1912, during the largest volcanic eruption of the 20th century, in which it released 30 times the volume of magma of the 1980 eruption of Mount St. Helens.

Occurring during the supergreenhouse climate of the Early Toarcian Thermal Maximum (ETTM), the Early Toarcian extinction was associated with large igneous province volcanism, considerable CO2 emissions which elevated global temperatures, acidified the oceans, increased continental weathering and nutrients fluxes

The petrified forest was formed in connection with the eruption of the Zeisigwald volcano in the lower Permian and dates back about 291 million years.

The volcano has erupted relatively frequently since the Last Glacial Period, most recently in 2010, when, although relatively small for a volcanic eruption, it caused enormous disruption to air travel across northern and western Europe for a week.

According to Charles Darwin's subsidence model, the formation of an atoll is explained by the sinking of a volcanic island around which a coral fringing reef has formed.

A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava.

A volcanic dam is a type of natural dam produced directly or indirectly by volcanism, which holds or temporarily restricts the flow of surface water in existing streams, like a man-made dam.

The islands are volcanic in origin; Saya de Malha (35 mya) was the first of the Mascarene islands to rise out of the Indian Ocean due to the Réunion hotspot, followed by Nazareth Bank (approximately 2 mya later), Soudan Bank and Cargados Carajos.

The larger islands are volcanic in origin, mountainous, and covered in tropical moist forest.

Emissions of lava from depths of up to 3,600 m (11,800 ft) resulted in the formation of the Aeolian Islands, together with Ustica and a series of submarine volcanoes named Magnani, Vavilov, Marsili and Palinuro, as well as two that are unnamed.

Finally, volcanic actions created rounded, symmetrical domes like breasts, which were given the name of Demoiselles (or "young ladies"), though this is disputed.

The coral reefs are situated on the top of a large shield volcano, produced by eruptions of the Tasmantid Seamount Chain.