|
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera Formation
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning "coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kīlauea
Kīlauea ( , ) is an active shield volcano in the Hawaiian Islands. Located along the southeastern shore of the Big Island of Hawaii, the volcano is between 210,000 and 280,000 years old and emerged above sea level about 100,000 years ago. Historically, it is the most active of the five volcanoes that together form Hawaii island. Kīlauea is also one of the most active volcanoes on Earth, and the most recent and currently ongoing eruption began on September 29, 2021, when several vents began to erupt lava within Halemaʻumaʻu, a pit crater in the volcano's summit caldera. Kīlauea is the second-youngest product of the Hawaiian hotspot and the current eruptive center of the Hawaiian–Emperor seamount chain. Because it lacks topographic prominence and its activities historically coincided with those of Mauna Loa, Kīlauea was once thought to be a satellite of its much larger neighbor. Structurally, Kīlauea has a large, fairly recently formed caldera at its summit and two ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piton De La Fournaise
Piton de la Fournaise (; en, "Peak of the Furnace") is a shield volcano on the eastern side of Réunion island (a French overseas department and region) in the Indian Ocean. It is currently one of the most active volcanoes in the world, along with Kīlauea in the Hawaiian Islands, Stromboli and Etna in Italy and Mount Erebus in Antarctica. A previous eruption began in August 2006 and ended in January 2007. The volcano erupted again in February 2007, on 21 September 2008, on 9 December 2010, which lasted for two days, and on 1 August 2015. The most recent eruption began on 7 December 2020. The volcano is located within Réunion National Park, a World Heritage Site. Residents of Réunion sometimes refer to Piton de la Fournaise simply as ''le Volcan'' ("the Volcano"). It is a major tourist attraction on Réunion island. Geology The uppermost section of the volcano is occupied by the Enclos Fouqué, a caldera wide. High cliffs, known as ''remparts'' in French, form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera De Taburiente
Caldera de Taburiente National Park ( es, Parque Nacional de la Caldera de Taburiente) is a national park on the island of La Palma, Canary Islands, Spain. It contains the Caldera de Taburiente, which dominates the northern part of the island, and was designated as a national park in 1954. The telescopes of the Roque de los Muchachos Observatory are situated very close to the summit. Toponym The word ''caldera'' means cauldron in Spanish. ''Taburiente'' is not a Spanish word but derives from the Guanche language and means "plain, level". Geography The caldera is about 10 km across, and in places the walls tower 2000 m over the caldera floor. The highest point is the Roque de los Muchachos on the northern wall, at 2426 m altitude, which can be reached by road. The Cumbrecita is at a lower point in the south-eastern part of the caldera's rim. In the south-west, the caldera opens to the sea, through a riverbed called the Barranco de las Angustias. The Cumbre Nueva is a rid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teide
Teide, or Mount Teide, ( es, El Teide, Pico del Teide, , "Peak of Teide") is a volcano on Tenerife in the Canary Islands, Spain. Its summit (at ) is the highest point in Spain and the highest point above sea level in the islands of the Atlantic. If measured from the ocean floor, its height of makes Teide the third-highest volcano in the world, and is described by UNESCO and NASA as Earth's third-tallest volcanic structure. However, as Teide was formed just 170,000 years ago due to volcanic activity following a catastrophic landslide, Teide's base is actually situated in the Las Cañadas crater (the remains of an older, eroded, extinct volcano) at a height of around above sea level. Teide's elevation above sea level makes Tenerife the tenth highest island in the world. Teide is an active volcano: its most recent eruption occurred in late 1909 from the El Chinyero vent on the northwestern Santiago rift. The United Nations Committee for Disaster Mitigation designated Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Dike
A ring dike or ring dyke is an intrusive igneous body that is circular, oval or arcuate in plan and has steep contacts. While the widths of ring dikes differ, they can be up to several thousand meters. The most commonly accepted method of ring dike formation is directly related to collapse calderas.Gudmundsson, Agust. "Formation of collapse calderas." ''Geology'' 16.9 (1988): 808–10. Caldera collapse and ring dike formation Collapse calderas form due to the emptying of a magma chamber. Effusive eruptions that take place on the flanks of the associated volcano and a fissure system that direct magma away from the chamber are both mechanisms that can empty a magma chamber. As pressure in the magma chamber changes, an increase in tensile stresses create tension fractures at the surface of the volcano. The geometry of the top of the magma chamber dictates the location and magnitude of the tension fractures. In addition, it was found that the higher the radius to depth ratio of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturgeon Lake Caldera
Sturgeon Lake Caldera is a large extinct caldera complex in Kenora District of Northwestern Ontario, Canada. It is one of the world's best preserved mineralized Neoarchean caldera complexes, containing well-preserved mafic-intermediate pillow lavas, pillow breccias, hyaloclastite and peperites, submarine lava domes and dome-associated breccia deposits. The complex is some 2.7 billion years old Retrieved on 2007-07-20 with a minimum strike length of . Geology The Sturgeon Lake Caldera contains a well preserved north facing homoclinal chain of |
Volcano
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. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Palma
La Palma (, ), also known as ''La isla bonita'' () and officially San Miguel de La Palma, is the most north-westerly island of the Canary Islands, Spain. La Palma has an area of making it the fifth largest of the eight main Canary Islands. The total population at the end of 2020 was 85,840, of which 15,716 lived in the capital, Santa Cruz de La Palma and about 20,467 in Los Llanos de Aridane. Its highest mountain is the Roque de los Muchachos, at , being second among the peaks of the Canaries only to the peaks of the Teide massif on Tenerife. In 1815, the German geologist Leopold von Buch visited the Canary Islands. It was as a result of his visit to Tenerife, where he visited the Las Cañadas caldera, and then later to La Palma, where he visited the Taburiente caldera, that the Spanish word for cauldron or large cooking pot – "caldera" – was introduced into the geological vocabulary. In the center of the island is the Caldera de Taburiente National Park; one of four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1815 Eruption Of Mount Tambora
Mount Tambora is a volcano on the island of Sumbawa in present-day Indonesia, then part of the Dutch East Indies, and its 1815 eruption was the most powerful volcanic eruption in recorded human history. This volcanic explosivity index (VEI) 7 eruption ejected of material into the atmosphere, and was the most recent confirmed VEI-7 eruption. Although the Mount Tambora eruption reached a violent climax on 10 April 1815, increased steaming and small phreatic eruptions occurred during the next six months to three years. The ash from the eruption column dispersed around the world and lowered global temperatures in an event sometimes known as the Year Without a Summer in 1816. This brief period of significant climate change triggered extreme weather and harvest failures in many areas around the world. Several climate forcings coincided and interacted in a systematic manner that has not been observed after any other large volcanic eruption since the early Stone Age. Chrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tenerife
Tenerife (; ; formerly spelled ''Teneriffe'') is the largest and most populous island of the Canary Islands. It is home to 43% of the total population of the Archipelago, archipelago. With a land area of and a population of 978,100 inhabitants as of January 2022, it is also the most populous island of Spain and of Macaronesia. Approximately five million tourists visit Tenerife each year; it is the most visited island in the archipelago. It is one of the most important tourist destinations in Spain and the world, hosting one of the world's largest carnivals, the Carnival of Santa Cruz de Tenerife. The capital of the island, , is also the seat of the island council (). That city and are the co-capitals of the autonomous community of the Canary Islands. The two cities are both home to governmental institutions, such as the offices of the presidency and the ministries. This has been the arrangement since 1927, when the Crown ordered it. (After the 1833 territorial division of Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bárðarbunga
Bárðarbunga (), is a stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland's most extensive glacier. The second highest mountain in Iceland, above sea level, Bárðarbunga is also part of a volcanic system that is approximately long and wide. Description Bárðarbunga is a subglacial stratovolcano under the ice cap of Vatnajökull glacier in the Vatnajökull National Park in Iceland. It rises to above sea level, making it the second highest mountain in Iceland, about lower than Hvannadalshnjúkur. The caldera is about 80 square kilometres, up to 10 km wide and about deep. The surrounding edges rise to 1,850 metres, but the base is on average close to 1,100 metres. The volcano is covered in ice to a depth of 850m, hiding the glacier-filled crater. The associated volcanic system and fissure swarm is about 190 km long and 25 km wide. Bárðarbunga was a little-known volcano in Iceland due to its remote location and infrequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
