A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contrast, intrusive rock refers to rocks formed by magma which cools below the surface.
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid lava, which travels farther and forms thinner flows than the more viscous lava erupted from a stratovolcano. Repeated eruptions result in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form.
A flood 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. Many flood basalts have been attributed to the onset of a hotspot reaching the surface of the earth via a mantle plume. Flood basalt provinces such as the Deccan Traps of India are often called traps, after the Swedish word trappa, due to the characteristic stairstep geomorphology of many associated landscapes.
Antofagasta de la Sierra is a volcanic field in Argentina. The main type of volcanic edifice in the area are scoria cones, it is formed by the La Laguna, Jote and Alumbrera volcanoes. The first and last of these form a sub-group which is better researched. Various dating methods have yielded ages from several million to several hundred thousand years ago, but some vents appear to be of Holocene age.
Mount Rinjani is an active volcano in Indonesia on the island of Lombok. Administratively the mountain is in the Regency of North Lombok, West Nusa Tenggara. It rises to 3,726 metres (12,224 ft), making it the second highest volcano in Indonesia. It is also the highest point in the Indonesian province of West Nusa Tenggara.
Cerro Azul is a shield volcano on the south western part of Isabela Island in the Galápagos Islands. At a height of 1,689 m (5,541 ft) it is the second highest peak in the Galapagos and due to its topographic prominence of over 1,500 m (4,921 ft) it is categorised as an ultra. The volcano is one of the most active in the Galapagos, with the last eruption between May and June 2008.
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. The vent is often a few metres wide and may be many kilometres long. Fissure vents can cause large flood basalts which run first in lava channels and later in lava tubes. After some time, the eruption tends to become focused at one or more spatter cones. Small fissure vents may not be easily discernible from the air, but the crater rows or the canyons built up by some of them are.
Nevado de Longaví is a volcano in the Andes of central Chile. The 3,242 m (10,636 ft) high volcano lies in the Linares Province, which is part of the Maule Region. It features a summit crater and several parasitic vents. The volcano is constructed principally from lava flows. Two collapses of the edifice have carved collapse scars into the volcano, one on the eastern slope known as Lomas Limpias and another on the southwestern slope known as Los Bueye. The volcano features a glacier and the Achibueno and Blanco rivers originate on the mountain.
Kostakan is a north-south trending chain of cinder cones located in the southern part of the Kamchatka Peninsula, Russia.
Puyuhuapi Volcanic Group is a volcanic group of cinder cones located at the head of Puyuhuapi Channel, in the Aysén del General Carlos Ibáñez del Campo Region of Chile.
Several types of volcanic eruptions—during which lava, tephra, and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series.
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars, along with less common volcanic forms such as tuyas and subglacial mounds.
Tequila Volcano, or Volcán de Tequila is a stratovolcano located near Tequila, Jalisco, in Mexico. It stands at a height of 2,920 meters above sea level,. Stratovolcanoes, also referred to as composite volcanoes, are the "iconically" conical-shaped volcanoes, found most commonly along subduction zones. Stratovolcanoes are composed of steeply dipping layers of lava, hardened ash, and other material that erupted from the main vent such as tephra and pumice. Commonly higher than 2500 meters above sea-level, Stratovolcanoes have gentle lower slopes which gradually become steeper the higher you get with a relatively small summit crater. Due to their eruptions, Stratovolcanoes have several distinct variations giving some a specific feature such as calderas and amphitheaters.
Puyehue and Cordón Caulle are two coalesced volcanic edifices that form a major mountain massif in Puyehue National Park in the Andes of Ranco Province, in the South of Chile. In volcanology this group is known as the Puyehue-Cordón Caulle Volcanic Complex (PCCVC). Four volcanoes constitute the volcanic group or complex, the Cordillera Nevada caldera, the Pliocene Mencheca volcano, Cordón Caulle fissure vents and the Puyehue stratovolcano.
Ardoukôba is a fissure vents volcano in Djibouti. Located on the coast 100 kilometres (62 mi) from Djibouti City, its summit is situated at 298 metres (978 ft) above sea level. It last erupted in November 1978 following an earthquake, the area having been dormant for 3,000 years. The volcano's rift is 17 kilometres (11 mi) in width, and has a depth of 800 metres (2,600 ft).
The Tengchong Volcanic Field (TVF) is a Cenozoic volcanic field located in the Southeastern margin of the Tibetan Plateau around 40 km from the Chinese border with Myanmar. The TVF is uniquely the only region affected by Quaternary volcanism that is part of the Himalayan Geothermal Belt caused by the Indo-Asian continent-continent collision. The TVF is characterized by hydrothermal activity and large-scale eruptions last recorded in 1609CE. Although the volcanoes themselves are considered extinct, several geothermal fields geographically linked to the TVF are still highly active. Evidence for geothermal activity can be linked to several prevalent active hot-springs located predominantly within the vicinity of the volcanoes in the TVF. Holocene eruptions occurred predominantly in the three largest volcanoes in the TVF named the Dayingshan, Maa'nshan and Heikongshan, the highest of which (Dayingshan) reaches 2865 meters above sea level. The volcanoes are distributed in a string-like pattern clustered from North to South in the middle on the Tengchong basin and are characterized by post-collisional high-Potassium (K) calc-alkaline series eruptions. The TVF provides unique geographical and geological knowledge as understanding the geological processes of creation provides insight into aspects such as the history of volcanism during the Quaternary Era in the region and as well as compositional information of its source and crustal assimilants. The TVF can be visited in the Tengchong Volcanic Geothermal National Geological Park.`
The Udokan Plateau is a volcanic field in Transbaikalia, Russia. It covers a surface area of 3,000 square kilometres (1,200 sq mi) northeast of Lake Baikal in North Asia. Volcanism in the Udokan Plateau included both basaltic lava flows and later individual volcanic cones. Volcanism commenced in the Miocene and continued on into the Holocene.
The Sand Mountain Volcanic Field is a volcanic field in the upper McKenzie River watershed, located in the United States in Oregon. Part of the Cascade Volcanic Arc, it lies southwest of Mount Jefferson and northwest of Belknap Crater and Mount Washington. Its highest elevation is 5,463 feet (1,665 m).
North Arch volcanic field is an underwater volcanic field north of Oahu, Hawaii. It covers an area of about 25,000 square kilometres (9,700 sq mi) and consists of large expanses of alkali basalt, basanite and nephelinite that form extensive lava flows and volcanic cones. Some lava flows are longer than 100 kilometres (62 mi).
