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.
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high to intermediate levels of silica, with lesser amounts of less viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as 15 km (9 mi).
The Ring of Fire is a tectonic belt, about 40,000 km (25,000 mi) long and up to about 500 km (310 mi) wide, which circumscribes the Pacific Ocean. It contains between 750 and 915 volcanoes, around two-thirds of the world total, and 90% of the world's earthquakes, including 81% of its largest, take place within the belt.
Mount Galunggung is an active stratovolcano in West Java, Indonesia, around 80 km (50 mi) southeast of the West Java provincial capital, Bandung. Mount Galunggung is part of the Sunda Arc extending through Sumatra, Java and the Lesser Sunda Islands, which has resulted from the subduction of the Australian plate beneath the Eurasian plate.
Mount Mazama is a complex volcano in the western U.S. state of Oregon, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major eruption approximately 7,700 years ago. The volcano is in Klamath County, in the southern Cascades, 60 miles (97 km) north of the Oregon–California border. Its collapse, due to the eruption of magma emptying the underlying magma chamber, formed a caldera that holds Crater Lake. The mountain is in Crater Lake National Park. Mount Mazama originally had an elevation of 12,000 feet (3,700 m), but following its climactic eruption this was reduced to 8,157 feet (2,486 m). Crater Lake is 1,943 feet (592 m) deep, the deepest freshwater body in the U.S. and the second deepest in North America after Great Slave Lake in Canada.
Mount Spurr (Dena'ina: K'idazq'eni) is a stratovolcano in the Aleutian Arc of Alaska, named after United States Geological Survey geologist and explorer Josiah Edward Spurr, who led an expedition to the area in 1898. The Alaska Volcano Observatory (AVO) currently rates Mount Spurr as Level of Concern Color Code Green. The mountain is known aboriginally by the Dena'ina Athabascan name K'idazq'eni, literally 'that which is burning inside'.
The Sunda Arc is a volcanic arc that produced the volcanoes that form the topographic spine of the islands of Sumatra, Nusa Tenggara, and Java, the Sunda Strait and the Lesser Sunda Islands. The Sunda Arc begins at Sumatra and ends at Flores, and is adjacent to the Banda Arc. The Sunda Arc is formed via the subduction of the Indo-Australian Plate beneath the Sunda and Burma plates at a velocity of 63–70 mm/year.
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.
The Ijen volcano complex is a group of composite volcanoes located on the border between Banyuwangi Regency and Bondowoso Regency of East Java, Indonesia. It is known for its blue fire, acidic crater lake, and labour-intensive sulfur mining.
Emperor of China is a submarine volcano in the western part of the Banda Sea, Indonesia. This volcano is part of a chain with Nieuwerkerk volcano, known scientifically as the Emperor of China–Nieuwkerk (NEC) ridge, the depth of which is ranging from 3,100–2,700 metres (10,170–8,858 ft).
Sorikmarapi is a highly vegetated stratovolcano on Sumatra island, Indonesia. It has a 600 m wide of crater lake at the summit and some sulfur deposits. A small parasitic crater, called Danau Merah, is found at the upper southeast flank of the mountain and several solfatara fields at the eastern flank. During the 19th and 20th century, small phreatic eruptions occurred.
Mount Papandayan is a complex stratovolcano, located in Garut Regency, to the southeast of the city of Bandung in West Java, Indonesia. It is about 15 kilometres (9.3 mi) to the southwest of the town of Garut. At the summit, there are four large craters which contain active fumarole fields. An eruption in 1772 caused the northeast flank to collapse producing a catastrophic debris avalanche that destroyed 40 villages and killed nearly 3,000 people. The eruption truncated the volcano into a broad shape with two peaks and a flat area 1.1 km wide with Alun-Alun crater in the middle, making the mountain appear as a twin volcano; one of the peaks is called Papandayan and the other Mount Puntang.
Mount Besar is a stratovolcano in the southeast of Sumatra, Indonesia. A minor sulfur deposit can be found in the crater. A big solfatara field called Marga Bayur is located along its north–south-west flanks or the Semangko fault system.
Mount Sempu is a volcano in the northern arm of Sulawesi, Indonesia, which contains a 3 km wide caldera. A maar, called Kawah Masem, was formed in the south-west of the caldera and contains a crater lake. Sulfur deposits have been extracted from the maar since 1938. Historical records, however, are unknown from the volcano.
Aucanquilcha is a massive stratovolcano located in the Antofagasta Region of northern Chile, just west of the border with Bolivia and within the Alto Loa National Reserve. Part of the Central Volcanic Zone of the Andes, the stratovolcano has the form of a ridge with a maximum height of 6,176 metres (20,262 ft). The volcano is embedded in a larger cluster of volcanoes known as the Aucanquilcha cluster. This cluster of volcanoes was formed in stages over eleven million years of activity with varying magma output, including lava domes and lava flows. Aucanquilcha volcano proper is formed from four units that erupted between 1.04–0.23 million years ago. During the ice ages, both the principal Aucanquilcha complex and the other volcanoes of the cluster were subject to glaciation, resulting in the formation of moraines and cirques.
Tacora is a stratovolcano located in the Andes of the Arica y Parinacota Region of Chile. Near the border with Peru, it is one of the northernmost volcanoes of Chile. It is part of the Central Volcanic Zone in Chile, one of the four volcanic belts of the Andes. The Central Volcanic Zone has several of the highest volcanoes in the world. Tacora itself is a stratovolcano with a caldera and a crater. The youngest radiometric age is 50,000 years ago and it is heavily eroded by glacial activity.
Volcán Putana, sometimes referred to as Jorqencal or Machuca, is a stratovolcano located In the Central Volcanic Zone (CVZ) of the Andes on the border between Bolivia and Chile and close to the Sairecabur volcanic complex. Its summit is 5,884 metres (19,304 ft) above sea level and contains a summit crater with two smaller craters nested within it. Beneath the summit, the volcano features a number of lava domes and lava flows, some of which originated in flank vents.
Damer, or Damar,, also called Kenli Island, is a small volcanic island in the Barat Daya Islands group in Indonesia's Maluku province, on the southern side of the Banda Sea. It is flanked by four smaller uninhabited islands - one to the east (Layeni), one to the west and two to the south. Together they are called the Damar Islands, and constitute one administrative district within the Maluku Barat Daya Regency. The district has a land area of 392.29 km2 and had a population of 5,718 at the 2020 Census; the official estimate as at mid 2022 was 5,727, all on Damer Island itself.
Lastarria is a 5,697 metres (18,691 ft) high stratovolcano that lies on the border between Chile and Argentina. It is remote, and the surroundings are uninhabited but can be reached through an unpaved road. The volcano is part of the Central Volcanic Zone, one of the four segments of the volcanic arc of the Andes. Over a thousand volcanoes—of which about 50 are active—lie in this over 1,500 kilometres (930 mi) long chain of volcanoes, which is generated by subduction of the Nazca Plate beneath the South American Plate.
