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, tephra, pumice and ash. 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 (9.3 mi).
The Ring of Fire is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. In a large 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements. It has 452 volcanoes. The Ring of Fire is sometimes called the circum-Pacific belt.
Lanzarote is a Spanish island, the northernmost and easternmost of the autonomous Canary Islands in the Atlantic Ocean. It is located approximately 125 kilometres off the north coast of Africa and 1,000 kilometres from the Iberian Peninsula. Covering 845.94 square kilometres, Lanzarote is the fourth-largest of the islands in the archipelago. With 149,183 inhabitants, it is the third-most populous Canary Island, after Tenerife and Gran Canaria. In the centre-west of the island is Timanfaya National Park, one of its main attractions. The capital is Arrecife.
A shield volcano is a type of volcano usually composed almost entirely of fluid lava flows. It is named for its low profile, resembling a warrior's shield lying on the ground. This is caused by the highly fluid lava erupted, which travels farther than lava erupted from a stratovolcano, and results in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form.
Kīlauea is an active shield volcano in the Hawaiian Islands, and the most active of the five volcanoes that together form the island of Hawaiʻi. Located along the southern shore of the island, the volcano is between 210,000 and 280,000 years old and emerged above sea level about 100,000 years ago.
Hawaiʻi Volcanoes National Park, established on August 1, 1916, is an American national park located in the U.S. state of Hawaii on the island of Hawaii. The park encompasses two active volcanoes: Kīlauea, one of the world's most active volcanoes, and Mauna Loa, the world's most massive shield volcano. The park provides scientists with insight into the birth and development of the Hawaiian Islands, and ongoing studies into the processes of volcanism. For visitors, the park offers dramatic volcanic landscapes, as well as glimpses of rare flora and fauna.
The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse array of maars, tuff rings, scoria cones, and lava flows. Aside from Rangitoto, which erupted repeatedly, no volcano has erupted twice, but eruptions lasted for various periods ranging from a few weeks to several years. The field is fuelled entirely by basaltic magma, unlike the explosive subduction-driven volcanism in the central North Island, such as at Mount Ruapehu and Lake Taupo. The field is currently dormant, but could become active again.
The fifteen volcanoes that make up the eight principal islands of Hawaii are the youngest in a chain of more than 129 volcanoes that stretch 5,800 kilometres (3,600 mi) across the North Pacific Ocean, called the Hawaiian-Emperor seamount chain. Hawaiʻi's volcanoes rise an average of 4,572 metres (15,000 ft) to reach sea level from their base. The largest, Mauna Loa, is 4,169 metres (13,678 ft) high. As shield volcanoes, they are built by accumulated lava flows, growing a few meters/feet at a time to form a broad and gently sloping shape.
Mount Rinjani or Gunung 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.
Kelud is an active stratovolcano located in East Java, Indonesia. Like many Indonesian volcanoes and others on the Pacific Ring of Fire, Kelud is known for large explosive eruptions throughout its history. More than 30 eruptions have occurred since 1000 AD. In 2007, an effusive explosion filled the crater with a lava dome. It last erupted on February 13, 2014, destroying the lava dome and ejecting boulders, stones and ashes up to West Java about 500 kilometers from Mount Kelud. The crater filled with water during the rainy season.
Cueva de los Verdes is a lava tube and tourist attraction of the Haria municipality on the island of Lanzarote in the Canary Islands (Spain). The cave lies within the Monumento Natural del Malpaís de La Corona, a protected area of the Canary Islands.
The Boring Lava Field is a Plio-Pleistocene volcanic field with cinder cones, small shield volcanoes, and lava flows in the northern Willamette Valley of the U. S. state of Oregon. Located 12 miles (19 km) southeast of downtown Portland, the field got its name from the town of Boring, Oregon, which lies just southeast of the most dense cluster of lava vents. The zone became active about 2.7 million years ago, with long periods of activity interspersed with quiescence. Its last eruptions took place about 57,000 years ago at the Beacon Rock cinder cone volcano; the individual volcanic vents of the field are considered extinct, but the field itself is not.
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.
Speleonectes atlantida is a species of eyeless crustacean in the order Nectiopoda. It was discovered in August 2009 in the Tunnel de la Atlantida, the world's longest submarine lava tube on Lanzarote in the Canary Islands off the west coast of North Africa. Like other remipedes, the species is equipped with venomous fangs.
Kadovar is a volcanic island in Papua New Guinea north-east of the much larger island of New Guinea. The only known eruption occurred in January 2018. There were some heightened thermal phenomena in 1976.
The 2010 eruptions of Eyjafjallajökull were volcanic events at Eyjafjallajökull in Iceland which, although relatively small for volcanic eruptions, caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010. Additional localised disruption continued into May 2010. The eruption was declared officially over in October 2010, when snow on the glacier did not melt. From 14–20 April, ash from the volcanic eruption covered large areas of Northern Europe. About 20 countries closed their airspace to commercial jet traffic and it affected approximately 10 million travellers.
Lunar lava tubes are sub-surface tunnels on the Moon that are believed to have formed during basaltic lava flows. When the surface of a lava tube cools, it forms a hardened lid that contains the ongoing lava flow beneath the surface in a conduit-shaped passage. Once the flow of lava diminishes, the tunnel may become drained, forming a hollow void. Lunar lava tubes are formed on surfaces that have a slope that ranges in angle from 0.4° to 6.5°. Lunar lava tubes may be as wide as 500 metres (1,600 ft) before they become unstable against gravitational collapse. However, stable tubes may still be disrupted by seismic events or meteoroid bombardment.
