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Al Wahbah Crater
Al Wahbah Crater (), 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. Origin 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 the crater, but they are disused. There are springs near the pl ... [...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 diox ... [...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.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 always h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harrat Rahat
Ḥarrat Rahāṭ () 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 Islamic holy city of Medina; this was its last eruption A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has .... 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 activity since 2009. See also * List of volcanoes in Saudi Arabia * Sarat Mountains ** Hijaz Mountains External links YouTube 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] |
Sarawat Mountains
The Sarawat Mountains (), also known as the Sarat in singular case, is a mountain range 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 Fayfa, Asir, Taif, and the Hijaz (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 Plateau. In Yemen, the Sarawat are divided i ... [...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 commonly defined as a vent or fissure 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 fo ... [...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 colloquially 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, except for the Hyphaene genus, who has branched palms. 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, especially in regions like the Middle East and North Africa. A wide range of common products and foods are de ... [...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, .... References External links * Geology journals Wiley (publisher) academic journals Geological Society of London academic journals Academic journals 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 (sometimes colloquially but incorrectly referred to as ''lava'') 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 volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...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] |
