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San Joaquin (Equatorial Guinea)
San Joaquin is a forested basaltic shield volcano forming the southeastern corner of Equatorial Guinea's Bioko Island. Its summit contains a small lake-filled caldera and its northeastern flank is home to a crater lake. The geologic history of San Joaquin is poorly known but the International Association of Volcanology and Chemistry of the Earth's Interior has classified the volcano as having been active in the last 2,000 years. See also * List of volcanoes in Equatorial Guinea This is a list of active and extinct volcanoes in Equatorial Guinea. References {{Global Volcanism Program Equatorial Guinea Volcanoes A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows ... References Shield volcanoes of Equatorial Guinea Polygenetic shield volcanoes Calderas of Equatorial Guinea {{EquatorialGuinea-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioko
Bioko (; historically Fernando Po; bvb, Ëtulá Ëria) is an island off the west coast of Africa and the northernmost part of Equatorial Guinea. Its population was 335,048 at the 2015 census and it covers an area of . The island is located off the Ambazonian segment of Cameroon, in the Bight of Biafra portion of the Gulf of Guinea. Its geology is volcanic; its highest peak is Pico Basile at . Malabo, on the north coast of the island, is the capital city of Equatorial Guinea. Etymology Bioko's native name is ''Ëtulá Ëria'' in the Bube language. For nearly 500 years, the island was known as ''Fernando Po'' ( pt, Fernando Pó, links=no; es, Fernando Poo, links=no), named for Portuguese navigator Fernão do Pó. Between 1973 and 1979 the island was named ''Macías Nguema Biyogo'' after the then president of Equatorial Guinea; the current name, Bioko, dates from 1979 and is in honour of politician Cristino Seriche Bioko. Geography Bioko has a total area of . It is long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Guinea
Equatorial Guinea ( es, Guinea Ecuatorial; french: Guinée équatoriale; pt, Guiné Equatorial), officially the Republic of Equatorial Guinea ( es, link=no, República de Guinea Ecuatorial, french: link=no, République de Guinée équatoriale, pt, link=no, República da Guiné Equatorial), *french: link=no, République de Guinée équatoriale * pt, link=no, República da Guiné Equatorial is a country on the west coast of Central Africa, with an area of . Formerly the colony of Spanish Guinea, its post-independence name evokes its location near both the Equator and the Gulf of Guinea. , the country had a population of 1,468,777. Equatorial Guinea consists of two parts, an insular and a mainland region. The insular region consists of the islands of Bioko (formerly ''Fernando Pó'') in the Gulf of Guinea and Annobón, a small volcanic island which is the only part of the country south of the equator. Bioko Island is the northernmost part of Equatorial Guinea and is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shield Volcano
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 (low viscosity) 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. Shield volcanoes are found wherever fluid low-silica lava reaches the surface of a rocky planet. However, they are most characteristic of ocean island volcanism associated with hot spots or with continental rift volcanism. They include the largest volcanoes on earth, such as Tamu Massif and Mauna Loa. Giant shield volcanoes are found on other planets of the Solar System, including Olympus Mons on Mars and Sapas Mons on Venus. Etymology The term 'shield volcano' is taken from the German term ''Schildvulkan'', coined by the Austrian geologist Eduard Suess in 1888 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shield Volcano
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 (low viscosity) 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. Shield volcanoes are found wherever fluid low-silica lava reaches the surface of a rocky planet. However, they are most characteristic of ocean island volcanism associated with hot spots or with continental rift volcanism. They include the largest volcanoes on earth, such as Tamu Massif and Mauna Loa. Giant shield volcanoes are found on other planets of the Solar System, including Olympus Mons on Mars and Sapas Mons on Venus. Etymology The term 'shield volcano' is taken from the German term ''Schildvulkan'', coined by the Austrian geologist Eduard Suess in 1888 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioko Island
Bioko (; historically Fernando Po; bvb, Ëtulá Ëria) is an island off the west coast of Africa and the northernmost part of Equatorial Guinea. Its population was 335,048 at the 2015 census and it covers an area of . The island is located off the Ambazonian segment of Cameroon, in the Bight of Biafra portion of the Gulf of Guinea. Its geology is volcanic; its highest peak is Pico Basile at . Malabo, on the north coast of the island, is the capital city of Equatorial Guinea. Etymology Bioko's native name is ''Ëtulá Ëria'' in the Bube language. For nearly 500 years, the island was known as ''Fernando Po'' ( pt, Fernando Pó, links=no; es, Fernando Poo, links=no), named for Portuguese navigator Fernão do Pó. Between 1973 and 1979 the island was named ''Macías Nguema Biyogo'' after the then president of Equatorial Guinea; the current name, Bioko, dates from 1979 and is in honour of politician Cristino Seriche Bioko. Geography Bioko has a total area of . It is long fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Volcanic crater, 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 language, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Crater Lake
A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption. Formation Lakes in calderas fill large craters formed by the collapse of a volcano during an eruption. Lakes in maars fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the crater rim, is filled by water. The water may come from precipitation, groundwater circulation (often hydrothermal fluids in the case of volcanic craters) or melted ice. Its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the upper portion of the lake is contained only by its adjacent natural volcanic dam; continued leakage through or surface outflow ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Association Of Volcanology And Chemistry Of The Earth's Interior
The International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) is a learned society that focuses on research in volcanology, efforts to mitigate volcanic disasters, and research into closely related disciplines, such as igneous geochemistry and petrology, geochronology, volcanogenic mineral deposits, and the physics of the generation and ascent of magmas in the upper mantle and crust. It is one of eight constituent associations of the International Union of Geodesy and Geophysics (IUGG). IAVCEI is run by an executive committee whose membership changes every four years. The Executive determines policies for the Association, enacting them through a series of commissions and task groups. '' Bulletin of Volcanology'' is the journal of IAVCEI.IAVCEI About Us. Retrieved 01 Apr 2015. History The |
List Of Volcanoes In Equatorial Guinea ...
This is a list of active and extinct volcanoes in Equatorial Guinea. References {{Global Volcanism Program Equatorial Guinea Volcanoes 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shield Volcanoes Of Equatorial Guinea
A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from close-ranged weaponry or projectiles such as arrows, by means of active blocks, as well as to provide passive protection by closing one or more lines of engagement during combat. Shields vary greatly in size and shape, ranging from large panels that protect the user's whole body to small models (such as the buckler) that were intended for hand-to-hand-combat use. Shields also vary a great deal in thickness; whereas some shields were made of relatively deep, absorbent, wooden planking to protect soldiers from the impact of spears and crossbow bolts, others were thinner and lighter and designed mainly for deflecting blade strikes (like the roromaraugi or qauata). Finally, shields vary greatly in shape, ranging in roundness to angularity, proportional length and width, symmetry and edge pattern; differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygenetic Shield Volcanoes
Polygenesis can refer to: * Polygenesis (linguistics), a theory of language origin * Polygenism, a theory of human origin * Gene duplication Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene. ..., a form of genetic disorder resulting in the overexpression of a particular gene Gourav * Polygenetic landforms, landforms formed the accumulative action of various processes {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
