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Phreatic Eruption
A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evaporation of water to steam, resulting in an explosion of steam, water, ash, rock, and volcanic bombs. At Mount St. Helens in Washington state, hundreds of steam explosions preceded the 1980 Plinian eruption of the volcano. A less intense geothermal event may result in a mud volcano. Phreatic eruptions typically include steam and rock fragments; the inclusion of liquid lava is unusual. The temperature of the fragments can range from cold to incandescent. If molten magma is included, volcanologists classify the event as a phreatomagmatic eruption. These eruptions occasionally create broad, low-relief craters called '' maars''. Phreatic explosions can be accompanied by carbon dioxide or hydrogen sulfide gas-emissions. Carbon diox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phreatic Eruption-numbers
''Phreatic'' is a term used in hydrology to refer to aquifers, in speleology to refer to cave passages, and in volcanology to refer to a type of volcanic eruption. Hydrology The term phreatic (the word originates from the Greek language, Greek , meaning "well" or "spring") is used in hydrology and the earth sciences to refer to matters relating to groundwater (an aquifer) below the water table. The term 'phreatic surface' indicates the location where the pore water pressure is under atmospheric conditions (i.e., the pressure head is zero). This surface usually coincides with the water table. The slope of the phreatic surface is assumed to indicate the direction of groundwater movement in an unconfined aquifer. The phreatic zone, below the phreatic surface where rock and soil are saturated with water, is the counterpart of the vadose zone, or unsaturated zone, above. Unconfined aquifers are also called phreatic aquifers because the phreatic surface provides their upper boundary. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maar
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 maar characteristically fills with water to form a relatively shallow crater lake, which may also be called a maar.David S.G. Thomas and Andrew Goudie (eds.), ''The Dictionary of Physical Geography'' (Oxford: Blackwell, 2000), 301. . Maars range in size from across and from deep. Most maars fill with water to form natural lakes. Most maars have low rims composed of a mixture of loose fragments of volcanic rocks and rocks torn from the walls of the diatreme. Etymology The name ''maar'' comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. The word evolved from its first use in German in the modern geological sense in 1819 and is now used in English and in the geological sciences as the term for the explosion crater, even if water from rainfall might alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Institution
The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase and diffusion of knowledge". Founded on August 10, 1846, it operates as a trust instrumentality and is not formally a part of any of the Federal government of the United States#branches, three branches of the federal government. The institution is named after its founding donor, British scientist James Smithson. It was originally organized as the United States National Museum, but that name ceased to exist administratively in 1967. The Smithsonian Institution has historical holdings of over 157 million items, 21 museums, 21 libraries, 14 education and research centers, a zoo, and historical and architectural landmarks, mostly located in Washington, D.C. Additional facilities are located in Maryland, New York (state), New York, and Virg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recorded History
Recorded history or written history describes the historical events that have been recorded in a written form or other documented communication which are subsequently evaluated by historians using the historical method. For broader world history, recorded history begins with the accounts of the ancient world around the 4th millennium BCE, and it coincides with the invention of writing. For some geographic regions or cultures, written history is limited to a relatively recent period in human history because of the limited use of written records. Moreover, human cultures do not always record all of the information which is considered relevant by later historians, such as the full impact of natural disasters or the names of individuals. Recorded history for particular types of information is therefore limited based on the types of records kept. Because of this, recorded history in different contexts may refer to different periods of time depending on the topic. The interpr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1883 Eruption Of Krakatoa
Beginning on 20 May 1883, and ending on 21 October 1883, the volcanic island of Krakatoa, located in the Sunda Strait, had repeated, months long Types of volcanic eruptions, volcanic eruptions. The most destructive of these eruptions occurred on 27 August, when over 70% of the island and its Krakatoa archipelago, surrounding archipelago were destroyed when it erupted so violently it collapsed itself into a caldera. The August eruption had an estimated Volcanic explosivity index, Volcanic Explosivity Index (VEI) of 6, and is List of volcanic eruptions by death toll, one of the deadliest and most destructive volcanic events in recorded history. The explosion was heard away in Perth, Western Australia, and Rodrigues near Mauritius, away. The acoustic pressure wave circled the globe more than three times. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were felt worldwide in the days and weeks after the volcano's e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, Indonesia is the world's largest archipelagic state and the List of countries and dependencies by area, 14th-largest country by area, at . With over 280 million people, Indonesia is the world's List of countries and dependencies by population, fourth-most-populous country and the most populous Islam by country, Muslim-majority country. Java, the world's List of islands by population, most populous island, is home to more than half of the country's population. Indonesia operates as a Presidential system, presidential republic with an elected People's Consultative Assembly, legislature and consists of Provinces of Indonesia, 38 provinces, nine of which have Autonomous administrative divisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krakatoa
Krakatoa (), also transcribed (), is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung. The caldera is part of a volcanic island group (Krakatoa archipelago) comprising four islands. Two of them are known as Lang Island, Lang and Verlaten Island, Verlaten; another, Rakata, is the only remnant of an island mostly destroyed by an 1883 eruption of Krakatoa, eruption in 1883 which created the caldera. In 1927, a fourth island, Anak Krakatoa, or "Child of Krakatoa", emerged from the caldera formed in 1883. There has been new eruptive activity since the late 20th century, with a large collapse causing 2018 Sunda Strait tsunami, a deadly tsunami in December 2018. Historical significance The most notable eruptions of Krakatoa culminated in a series of massive explosions over 26–27 August 1883, which were among the most violent volcanic events in recorded history. With an estimated Volcanic explosivity index (VEI) of 6, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fissure Vent
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. Volcanic cones and their craters that are aligned along a fissure form a crater row. Small fissure vents may not be easily discernible from the air, but the crater rows (see Laki) or the canyons (see Eldgjá) built up by some of them are. The dikes that feed fissures reach the surface from depths of a few kilometers and connect them to deeper magma reservoirs, often under volcanic centers. Fissures are usually found in or along rifts and rift zones, such as Iceland and the East African Rift. Fissure vents are often part of the structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2021 Cumbre Vieja Volcanic Eruption
An eruption at the Cumbre Vieja complex volcano, volcanic ridge, comprising the southern half of the Spain, Spanish island of La Palma in the Canary Islands, took place between 19 September and 13 December 2021. It was the first volcanic eruption on the island since the Teneguía#1971 eruption, eruption of Teneguía in 1971. At 85 days, it is the longest known and the most damaging volcanic eruption on La Palma since records began. The total damage caused by the volcano amounts up to 843 million euros. The lava flow covered over , prompting the evacuation of around 7,000 people. The lava flow was about wide at its widest point, about long and reached the sea, destroying more than 3,000 buildings, cutting the coastal highway and forming a new peninsula, as well as an extensive system of Tajogaite#Lava tubes, lava tubes. The town of Todoque, including its easternmost neighbourhood Los Campitos (Los Llanos de Aridane), Los Campitos, was completely destroyed by lava, which also reac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumbre Vieja
The Cumbre Vieja (; meaning "Old Summit") is an active Complex volcano, volcanic ridge on the island of La Palma in the Canary Islands, Spain. The spine of Cumbre Vieja trends in an approximate north–south direction, comprising the southern half of La Palma, with both summit ridge and flanks pockmarked by dozens of volcanic crater, craters and volcanic cone, cones. The 2021 Cumbre Vieja volcanic eruption, latest eruption began on 19 September 2021 in a forested area of Las Manchas, La Palma, Las Manchas locality known as Cabeza de Vaca. Voluminous lava flows quickly reached populated areas downslope, fanning out across settlements and banana plantations, destroying thousands of buildings and ultimately pouring over steep cliffs into the ocean to enlarge the island at several locations. The volcano went quiet on 13 December 2021, and on 25 December 2021, the local government declared the eruption to be over. Cumbre Vieja erupted twice in the 20th century, in 1949 (Volcán San J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Of Volcanology
The ''Bulletin of Volcanology'' is a peer reviewed scientific journal that is published ten times per year by Springer Science+Business Media. It is the official journal of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). The focus of the journal is volcanoes, volcanic products, eruptive behavior, and volcanic hazards. The Executive Editor is Marie Edmonds. The impact factor for ''Bulletin of Volcanology'' in 2020 is 2.517. Scope and history Applying geochemical, petrological, and geophysical techniques to understand volcanic systems (magmatic systems) and their evolution is part of this journal's focus. Publishing formats include original research papers, reviews, communications, and a discussion forum. Additionally, this journal is a continuation of ''Bulletin Volcanologique'' which was published first in 1922. In 1986 Springer-Verlag started publishing this journal with Volume 48. Abstracting and indexing ''Bulletin of Volcan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (island)
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, projected to rise to 158 million at mid 2025, Java is the world's most populous island, home to approximately 55.7% of the Indonesian population (only approximately 44.3% of Indonesian population live outside Java). Indonesia's capital city, Jakarta, is on Java's northwestern coast. Many of the best known events in Indonesian history took place on Java. It was the centre of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically and culturally. Four of Indonesia's eight UNESCO world heritage sites are located in Java: Ujung Kulon National Park ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
