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Al Wahbah Crater
Al Wahbah Crater ( ar, فَوْهَة ٱلْوَعْبَة, Fawhat al-Waʿbah), also ''Maqlaʿ Ṭamiyyah'' (), is a volcanic crater, which is about away from Ta'if on the western edge of the Harrat Kishb basalt plateau in the Hejazi region of Saudi Arabia (lat. 22.90632, lon. 41.13849). The Harrat Kishb plateau contains many volcanic cones. It is deep and in diameter. The bottom of the crater is covered with white sodium phosphate crystals. Origins While it was thought for some time that the crater was formed by a meteorite, as its appearance resembles that of the Barringer Crater, with its circular form and high sides, it is now commonly accepted by geologists that the crater is a maar crater, and was formed by volcanic activity in the form of an underground phreatic eruption – a massive steam explosion generated by molten basaltic magma coming into contact with subterranean water. Vegetation The remains of date palm plantations can be found halfway down the side of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 dioxide c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maars
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. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. Notes: * According to German Wikipedia's ''"Maar"'' article, in 1544 in his book ''Cosmographia'', Sebastian Münster (1488–1552) first applied the word "maar" (as ''Marh'') to the Ulmener Maar and the Laacher See. See: Sebastian Münster, ''Cosmographia'' (Basel, Switzerland: Heinrich Petri, 1544)p. 341. From p. 341: ''"Item zwen namhafftiger seen seind in der Eyfel / einer bey de schloß Ulmen / und ein ander bey dem Closter züm Laich / die seind sere tieff / habe kein ynflüß aber vil außflüß / die nennet man Marh unnd seind fischreich."'' (Also two noteworthy lakes are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harrat Rahat
Ḥarrat Rahāṭ ( ar, حَرَّة رَهَاط) is a volcanic lava field in the Hejazi region of Saudi Arabia. In 1256 CE, a lava flow erupted from six aligned scoria cones, and traveled to within of the Holiest sites in Islam, Islamic holy city of Medina; this was its last eruption. There were earlier eruptions, such as in 641 CE, which made finger-like flows to the east of the 1256 CE flow. It is the biggest lava field in Saudi Arabia. Nearby is Al Wahbah crater. There has been recent increase in seismic activitiy since 2009. See also * List of volcanoes in Saudi Arabia * Sarawat Mountains, Sarat Mountains ** Hijaz Mountains External linksYoutube video: The Active Volcano in Saudi Arabia; Harrat Rahat References Volcanoes of Saudi Arabia Lava fields Holocene volcanoes Hejaz ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hijaz Mountains
The Hijaz Mountains ( ar, جِبَال ٱلْحِجَاز, Jibāl al-Ḥijāz ()) or "Hejaz Range" is a mountain range located in the Hejazi region of western Saudi Arabia. The range runs north and south along the eastern coast of the Red Sea, and can thus be treated as including the Midian Mountains, and being part of the Sarawat Mountains, broadly speaking. Geography The western coastal escarpment of the Arabian Peninsula is composed of two mountain ranges, the Hijaz Mountain to the north and the Asir Mountains farther south, with a gap between them near the middle of the peninsula's coastline. From an elevation of , the range declines towards the vicinity of the gap about . The mountain wall drops abruptly on the western side toward the Red Sea, leaving the narrow coastal plain of Tihamah. The eastern slopes are not as steep, allowing rare rainfall to help create oasis around the springs and wells of the few wadis. River or ''wadi'' The Hijaz Mountains have been conje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarawat Mountains
The Sarawat Mountains ( ar, جِبَالُ ٱلسَّرَوَاتِ, Jibāl as-Sarawāt), also known as the Sarat, is a part of the Hijaz mountains in the western part of the Arabian Peninsula. In a broad sense, it runs parallel to the eastern coast of the Red Sea, and thus encompasses the mountains of Fifa', 'Asir and Taif (which can be seen as including the Midian Mountains). In a narrow sense, the Sarawat start in Taif city in Saudi Arabia, and extend to the Gulf of Aden in the south, running along the entire western coast of Yemen, in what used to be North Yemen, and extend eastwards into part of what used to be South Yemen, thus running parallel to the Gulf of Aden. Geology These mountains are mainly rocky though some contain vegetation. Many of the peaks are fairly young and jagged, but some are smoother from weathering. Nearing the Yemeni border, the Sarawat begin to spread into individual peaks, and the Hejaz turns from a cliff to a gradual ascent up to the Yemeni Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In Saudi Arabia ...
This is a partial list of active and extinct volcanoes in Saudi Arabia. References {{Asia topic, state=uncollapsed, List of volcanoes in Saudi Arabia 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] |
Palm Tree
The Arecaceae is a family of perennial flowering plants in the monocot order Arecales. Their growth form can be climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are called palm trees. Currently, 181 genera with around 2,600 species are known, most of which are restricted to tropical and subtropical climates. Most palms are distinguished by their large, compound, evergreen leaves, known as fronds, arranged at the top of an unbranched stem. However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of habitat within their range, from rainforests to deserts. Palms are among the best known and most extensively cultivated plant families. They have been important to humans throughout much of history. Many common products and foods are derived from palms. In contemporary times, palms are also widely used in landscaping. In many historical cultures, because of their importance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Today
''Geology Today'' is a bimonthly peer-reviewed scientific journal published by Wiley on behalf of the Geologists' Association and the Geological Society of London. The editor-in-chief is Peter Doyle (Geological Society of London). The journal covers all aspects of the Earth sciences. Abstracting and indexing The journal is abstracted and indexed in Aquatic Sciences and Fisheries Abstracts, EBSCO databases, ProQuest databases, Scopus, and The Zoological Record ''The Zoological Record'' (''ZR'') is an electronic index of zoological literature that also serves as the unofficial register of scientific names in zoology. It was started as a print publication in 1864 by the Zoological Society of London, a .... References External links * Geology journals Wiley (publisher) academic journals Geological Society of London academic journals Publications established in 1985 Geologists' Association 1985 establishments in the United Kingdom {{geology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...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. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. Notes: * According to German Wikipedia's ''"Maar"'' article, in 1544 in his book ''Cosmographia'', Sebastian Münster (1488–1552) first applied the word "maar" (as ''Marh'') to the Ulmener Maar and the Laacher See. See: Sebastian Münster, ''Cosmographia'' (Basel, Switzerland: Heinrich Petri, 1544)p. 341. From p. 341: ''"Item zwen namhafftiger seen seind in der Eyfel / einer bey de schloß Ulmen / und ein ander bey dem Closter züm Laich / die seind sere tieff / habe kein ynflüß aber vil außflüß / die nennet man Marh unnd seind fischreich."'' (Also two noteworthy lakes are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic
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 plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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