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Rift Zone
A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. Believed to be primarily caused by internal and gravitational stresses generated by magma emplacement within and across various regions of the volcano, rift zones allow the intrusion of magmatic dykes into the slopes of the volcano itself. The addition of these magmatic materials usually contributes to the further rifting of the slope, in addition to generating fissure eruptions from those dykes that reach the surface. It is the grouping of these fissures, and the dykes that feed them, that serves to delineate where and whether a rift zone is to be defined. The accumulated lava of repeated eruptions from rift zones along with the endogenous growth created by magma intrusions causes these volcanoes to have an elongated shape. Perhaps the best ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Rift Zone Kilauea
East is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fact that east is the direction where the Sun rises: ''east'' comes from Middle English ''est'', from Old English ''ēast'', which itself comes from the Proto-Germanic *''aus-to-'' or *''austra-'' "east, toward the sunrise", from Proto-Indo-European *aus- "to shine," or "dawn", cognate with Old High German ''*ōstar'' "to the east", Latin ''aurora'' 'dawn', and Greek ''ēōs'' 'dawn, east'. Examples of the same formation in other languages include Latin oriens 'east, sunrise' from orior 'to rise, to originate', Greek ανατολή anatolé 'east' from ἀνατέλλω 'to rise' and Hebrew מִזְרָח mizraḥ 'east' from זָרַח zaraḥ 'to rise, to shine'. ''Ēostre'', a Germanic goddess of dawn, might have been a personification of both da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only state not on the North American mainland, the only state that is an archipelago, and the only state in the tropics. Hawaii consists of 137 volcanic islands that comprise almost the entire Hawaiian Islands, Hawaiian archipelago (the exception, which is outside the state, is Midway Atoll). Spanning , the state is Physical geography, physiographically and Ethnology, ethnologically part of the Polynesian subregion of Oceania. Hawaii's ocean coastline is consequently the List of U.S. states and territories by coastline, fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Niihau, Kauai, Kauai, Oahu, Oahu, Molokai, Molokai, Lanai, Lānai, Kahoʻolawe, Kahoolawe, Maui, and Hawaii (island), Hawaii, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Eruption
A lateral eruption or lateral blast is a volcanic eruption which is directed laterally from a volcano rather than upwards from the summit. Lateral eruptions are caused by the outward expansion of flanks due to rising magma. Breaking occurs at the flanks of volcanoes making it easier for magma to flow outward. As magma is pushed upward towards the volcano it diverges towards the flanks before it has a chance to erupt from the crater. When the expanding flank finally gives it releases a flow of magma. More explosive lateral eruptions are referred to as lateral blasts. Some of the most notable examples of a lateral eruption include Mount St. Helens, Mount Pelée, and Mount Etna. Creation of a lateral eruption Most eruptions are caused by the immediate decompression of a magma chamber near the flanks of the volcano. During an eruption, the rapid decompression of magma may cause subsidence of the mountain, and if a flank collapses, a lateral eruption occurs. The directed nature o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture (geology)
A fracture is any separation in a geologic formation, such as a Joint (geology), ''joint'' or a Fault (geology), ''fault'' that divides the Rock (geology), rock into two or more pieces. A fracture will sometimes form a deep fissure or crevice in the rock. Fractures are commonly caused by Stress (physics), stress exceeding the rock strength, causing the rock to lose cohesion along its weakest plane. Fractures can provide Permeability (fluid), permeability for fluid movement, such as water or hydrocarbons. Highly fractured rocks can make good aquifers or Oil reservoir, hydrocarbon reservoirs, since they may possess both significant Permeability (fluid), permeability and fracture porosity. Brittle deformation Fractures are forms of brittle deformation. There are two types of primary brittle deformation processes. Tensile fracturing results in ''joints''. ''Shear fractures'' are the first initial breaks resulting from shear forces exceeding the cohesive strength in that plane. Aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craters Of The Moon National Monument And Preserve
Craters of the Moon National Monument and Preserve is a National monument (United States), U.S. national monument and national preserve in the Snake River Plain in central Idaho. It is along U.S. Route 20#Idaho, US 20 (Concurrency (road), concurrent with U.S. Route 93#Idaho, US 93 and U.S. Route 26#Idaho, US 26), between the small towns of Arco, Idaho, Arco and Carey, Idaho, Carey, at an average elevation of Sea level#AMSL, above sea level. The Monument was established on May 2, 1924. In November 2000, a presidential proclamation by Bill Clinton, President Clinton greatly expanded the Monument area. The 410,000-acre National Park Service portions of the expanded Monument were designated as Craters of the Moon National Preserve in August 2002.Record of Decision – FEIS GMP for Craters of the Moon NM and P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newberry Volcano
Newberry Volcano is a large, active, shield-shaped stratovolcano located about south of Bend, Oregon, United States, east of the major crest of the Cascade Range, within the Newberry National Volcanic Monument. Its highest point is Paulina Peak. Newberry is the largest volcano in the Cascade Volcanic Arc, with an area of when its lava flows are taken into account. From north to south, the volcano has a length of , with a width of and a total volume of approximately . It was named for the geologist and surgeon John Strong Newberry, who explored central Oregon for the Pacific Railroad Surveys in 1855. The volcano contains a large caldera, in diameter, known as the Newberry Caldera. Within the caldera are two lakes: Paulina Lake and East Lake. The volcano and its vicinity include many pyroclastic cones, lava flows and lava domes; Newberry has more than 400 vents, the most of any volcano in the contiguous United States. Glaciers may have once been present at the volcano, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Hierro
El Hierro (), nicknamed ''Isla del Meridiano'' (the "Meridian Island"), is the farthest south and west of the Canary Islands (an autonomous community of Spain), in the Atlantic Ocean off the coast of Africa, with a population of 11,659 (2023). Its capital is Valverde. At , it is the second smallest of the eight main islands of the Canaries with La Graciosa being the smallest. Name The name ''El Hierro'', although spelled like the Spanish word for 'iron', is not related to that word. The ''H'' in the name of the metal is derived from the ''F'' of Latin ''ferrum'' (compare ''higo'' for 'fig'), a phonetic mutation that was complete by the end of the Middle Ages. The confusion with the name of the metal had effects on the international naming of the island. As early as the 16th century, maps and texts called the island after the word for 'iron' in other languages: Portuguese ''Ferro'', French ''l'île de Fer'', and Latin '' Insula Ferri''. Nevertheless, the origin of the nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Palma
La Palma (, ), also known as ''La isla bonita'' () and historically San Miguel de La Palma, is the most northwesterly island of the Canary Islands, a Spanish autonomous community and archipelago in Macaronesia in the North Atlantic Ocean. La Palma has an area of making it the fifth largest of the eight main Canary Islands. The total population at the start of 2023 was 84,338, of whom 15,522 lived in the capital, Santa Cruz de La Palma and 20,375 in Los Llanos de Aridane. Its highest mountain is the Roque de los Muchachos, at , being second among the peaks of the Canaries after 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canary Islands
The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the continent being 100 kilometres (62 miles) away. The islands have a population of 2.25 million people and are the most populous overseas Special member state territories and the European Union, special territory of the European Union. The seven main islands are from largest to smallest in area, Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera, and El Hierro. The only other populated island is Graciosa, Canary Islands, La Graciosa, which administratively is dependent on Lanzarote. The archipelago includes many smaller islands and islets, including Alegranza, Islote de Lobos, Isla de Lobos, Montaña Clara, Roque del Oeste, and Roque del Este. It includes a number of rocks, including Roque de Garachico, Garachico and Roques de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
