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Yardang
A yardang is a streamlined protuberance carved from bedrock or any consolidated or semiconsolidated material by the dual action of wind abrasion by dust and sand and deflation (the removal of loose material by wind turbulence.) Yardangs become elongated features typically three or more times longer than wide, and when viewed from above, resemble the hull of a boat. Facing the wind is a steep, blunt face that gradually gets lower and narrower toward the lee end. Yardangs are formed by wind erosion, typically of an originally flat surface formed from areas of harder and softer material. The soft material is eroded and removed by the wind, and the harder material remains. The resulting pattern of yardangs is therefore a combination of the original rock distribution, and the fluid mechanics of the air flow and resulting pattern of erosion. Names The word itself is of Turkic origin, meaning ‘steep bank’, as this type of spectacular landscapes rising are best developed in the ...
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Yardangs On Mars
Yardangs are common in some regions on Mars, especially in the Medusae Fossae Formation. This formation is found in the Amazonis quadrangle and near the equator. They are formed by the action of wind on sand sized particles; hence they often point in the prevailing direction that the winds were blowing when they were formed. Because they exhibit very few impact craters they are believed to be relatively young. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Yardang, Yardangs are parts of rock that have been sand blasted into long, skinny ridges by bouncing sand particles blowing in the wind.Yardangs in Arsinoes Chaos
University of Arizona HiRISE Operations, 04 January 2015
Layers are ...
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Amazonis
Amazonis Planitia (, Latin ''Amāzŏnis'') is one of the smoothest plains on Mars. It is located between the Tharsis and Elysium volcanic provinces, to the west of Olympus Mons, in the Amazonis and Memnonia quadrangles, centered at . The plain's topography exhibits extremely smooth features at several different lengths of scale. A large part of the Medusae Fossae Formation lies in Amazonis Planitia. Its name derives from one of the classical albedo features observed by early astronomers, which was in turn named after the Amazons, a mythical race of warrior women. Age and composition Only approximately 100 million years old, these plains provide some of the fewest sedimentary layers impeding viewing of the Martian terrain, and closely resemble the composition of Earth's Iceland. Formed by free-flowing lava across great plains, Amazonis has been described by William Hartmann as a "bright dusty volcanic desert crossed by many fresh-looking lava flows." Amazonis has become t ...
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Eolian Erosion
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little or ...
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Sven Hedin
Sven Anders Hedin, KNO1kl RVO,Wennerholm, Eric (1978) ''Sven Hedin – En biografi'', Bonniers, Stockholm (19 February 1865 – 26 November 1952) was a Swedish geographer, topographer, explorer, photographer, travel writer and illustrator of his own works. During four expeditions to Central Asia, he made the Transhimalaya known in the West and located sources of the Brahmaputra, Indus and Sutlej Rivers. He also mapped lake Lop Nur, and the remains of cities, grave sites and the Great Wall of China in the deserts of the Tarim Basin. In his book '' Från pol till pol'' (''From Pole to Pole''), Hedin describes a journey through Asia and Europe between the late 1880s and the early 1900s. While traveling, Hedin visited Turkey, the Caucasus, Tehran, Iraq, lands of the Kyrgyz people and the Russian Far East, India, China and Japan. The posthumous publication of his ''Central Asia Atlas'' marked the conclusion of his life's work. Overview At 15 years of age, Hedin witness ...
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Great Sphinx Of Giza
The Great Sphinx of Giza is a limestone statue of a reclining sphinx, a mythical creature with the head of a human, and the body of a lion. Facing directly from west to east, it stands on the Giza Plateau on the west bank of the Nile in Giza, Egypt. The face of the Sphinx appears to represent the pharaoh Khafre. The original shape of the Sphinx was cut from the bedrock, and has since been restored with layers of limestone blocks. It measures long from paw to tail, high from the base to the top of the head and wide at its rear haunches. Its nose was broken off for unknown reasons between the 3rd and 10th centuries AD. The Sphinx is the oldest known monumental sculpture in Egypt and one of the most recognisable statues in the world. The archaeological evidence suggests that it was created by ancient Egyptians of the Old Kingdom during the reign of Khafre (). Names The original name the Old Kingdom creators gave the Sphinx is unknown, as the Sphinx temple, enclosure ...
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Dune
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat regions covered with wind-swept sand or dunes with little or no vegetation are called ''Erg (landform), ergs'' or ''sand seas''. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the wiktionary:stoss, stoss (upflow) side, where the sand is pushed up the dune, and have a shorter ''slip face'' in the lee side. The valley or trough between dunes is called a ''dune slack''. Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in othe ...
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Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos and Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a large impact feature. Days and seasons on Mars are comparable to those of Earth, as the planets have a similar rotation period a ...
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Tibesti Mountains
The Tibesti Mountains are a mountain range in the central Sahara, primarily located in the extreme north of Chad, with a small portion located in southern Libya. The highest peak in the range, Emi Koussi, lies to the south at a height of and is the highest point in both Chad and the Sahara. Bikku Bitti, the highest peak in Libya, is located in the north of the range. The central third of the Tibesti is of volcanic origin and consists of five volcanoes topped by large depressions: Emi Koussi, Tarso Toon, Tarso Voon, Tarso Yega and Toussidé. Major lava flows have formed vast plateaus that overlie Paleozoic sandstone. The volcanic activity was the result of a continental hotspot (geology), hotspot that arose during the Oligocene and continued in some places until the Holocene, creating fumaroles, hot springs, mud pools and deposits of natron and sulfur. Erosion has shaped volcanic spires and carved an extensive network of canyons through which run rivers subject to highly irregular ...
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Geological Society Of Glasgow
The Geological Society of Glasgow is a scientific society devoted to the study of geology in Scotland. The society contributed to the understanding of Scotland's glacial history, and the relationship between the Earth's rotation and climate change. The Geological Society of Glasgow is registered as a charity in Scotland. History The society was founded on 17 May 1858, by a group of amateur geology enthusiasts. The society organized its first field trip, to Campsie Glen, in June of that year. Some fossils from these early excursions are on display in the Kelvingrove Museum in Glasgow. The society continues to attract lecturers at the forefront of the field, and publishes field guides of the Glasgow region. Programs Each summer, the society runs day-long and residential field trips, open to members. Each winter, the society hosts a lecture series, open to all, in the Gregory Building at Glasgow University. Publications The ''Transactions of the Geological Society of Glasgow' ...
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Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediterranean Sea to the north, the Gaza Strip of Palestine and Israel to the northeast, the Red Sea to the east, Sudan to the south, and Libya to the west. The Gulf of Aqaba in the northeast separates Egypt from Jordan and Saudi Arabia. Cairo is the capital and largest city of Egypt, while Alexandria, the second-largest city, is an important industrial and tourist hub at the Mediterranean coast. At approximately 100 million inhabitants, Egypt is the 14th-most populated country in the world. Egypt has one of the longest histories of any country, tracing its heritage along the Nile Delta back to the 6th–4th millennia BCE. Considered a cradle of civilisation, Ancient Egypt saw some of the earliest developments of writing, agr ...
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