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Giant Current Ripples
Giant current ripples are active channel topographic forms up to 20 m high, which develop within near-thalweg areas of the main outflow valleys created by glacial lake outburst floods. Giant current ripple marks are large scale analogues of small current ripples formed in sandy stream sediments. The giant current ripple marks are important depositional forms in diluvial plain and mountain scablands. Descriptive features Up to the present, hundreds of locations of the fields of giant current ripples have been discovered in North America and Northern Asia. Here is a brief description of main characteristics of this relief and its sediments at the key, today most often visited, sites in the Altai and Tuva with the necessary references to the chief publications for the other territories. #Wave height from 2–20 m with the wavelength from 5–10 m to 300 m #Ripple marks are stretched transversely to the diluvial floods. They are clearly and regularly asymmetric. The proximal slope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channeled Scabland
The Channeled Scablands are a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods within the southeastern part of Washington.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. The Channeled Scablands were scoured by more than 40 cataclysmic floods during the Last Glacial Maximum and innumerable older cataclysmic floods over the last two million years. These floods were periodically unleashed whenever a large glacial lake broke through its ice dam and swept across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch. The last of the cataclysmic floods occurred between 18,200 and 14,000 years ago.Balbas, A.M., Barth, A.M., Clark, P.U., Clark, J., Caffee, M., O'Connor, J., Baker, V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and cover concepts such as pipe flow, dam design, fluidics and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue. Free surface hydraulics is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, canals, lakes, estuar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia Plateau
The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Columbia River. Geology During late Miocene and early Pliocene times, a flood basalt engulfed about of the Pacific Northwest, forming a large igneous province. Over a period of perhaps 10 to 15 million years, lava flow after lava flow poured out, ultimately accumulating to a thickness of more than 6,000 feet (1.8 km). As the molten rock came to the surface, the Earth's crust gradually sank into the space left by the rising lava. The Columbia River Basalt Group consists of seven formations: The Steens Basalt, Imnaha Basalt, Grande Ronde Basalt, Picture Gorge Basalt, Prineville Basalt, Wanapum Basalt, and Saddle Mountains Basalt. Many of these formations are subdivided into formal and informal members and flows. The subsidence of the crust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Lake Missoula
Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about and contained about of water, half the volume of Lake Michigan. The ''Glacial Lake Missoula National Natural Landmark'' is located about 110 kilometres (68 mi) northwest of Missoula, Montana, at the north end of the Camas Prairie Valley, just east of Montana Highway 382 and Macfarlane Ranch. It was designated as a National Natural Landmark in 1966 because it contains the great ripples (often measuring high and long) that served as a strong supporting element for J Harlen Bretz's contention that Washington State's Channeled Scablands were formed by repeated cataclysmic floods over only about 2,000 years, rather than through the millions of years of erosion that had been previously assumed. The lake was the result of an ice dam on the Clark Fork caused by the southern encroachment of a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently defined as the time between c. 129,000 and c. 11,700 years ago. The Late Pleistocene equates to the proposed Tarantian Age of the geologic time scale, preceded by the officially ratified Chibanian (formerly known as Middle Pleistocene) and succeeded by the officially ratified Greenlandian. The estimated beginning of the Tarantian is the start of the Eemian interglacial period (Marine Isotope Stage 5). It is held to end with the termination of the Younger Dryas, some 10th millennium BC, 11,700 years ago when the Holocene Epoch began. The term Upper Pleistocene is currently in use as a provisional or "quasi-formal" designation by the International Union of Geological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the fourth-largest state by area, the eighth-least populous state, and the third-least densely populated state. Its state capital is Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several unofficial ones, most notably "Big Sky Country", "The Treasure State", "Land of the Shining Mountains", and " The Last Best Place". The economy is primarily based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, gas, coal, mining, and lumber. The health ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Missoula
Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about and contained about of water, half the volume of Lake Michigan. The ''Glacial Lake Missoula National Natural Landmark'' is located about 110 kilometres (68 mi) northwest of Missoula, Montana, at the north end of the Camas Prairie Valley, just east of Montana Highway 382 and Macfarlane Ranch. It was designated as a National Natural Landmark in 1966 because it contains the great ripples (often measuring high and long) that served as a strong supporting element for J Harlen Bretz's contention that Washington State's Channeled Scablands were formed by repeated cataclysmic floods over only about 2,000 years, rather than through the millions of years of erosion that had been previously assumed. The lake was the result of an ice dam on the Clark Fork caused by the southern encroachment of a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Association For The Advancement Of Science
The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the betterment of all humanity. It is the world's largest general scientific society, with over 120,000 members, and is the publisher of the well-known scientific journal ''Science''. History Creation The American Association for the Advancement of Science was created on September 20, 1848, at the Academy of Natural Sciences in Philadelphia, Pennsylvania. It was a reformation of the Association of American Geologists and Naturalists. The society chose William Charles Redfield as their first president because he had proposed the most comprehensive plans for the organization. According to the first constitution which was agreed to at the September 20 meeting, the goal of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seattle
Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region of North America. The Seattle metropolitan area's population is 4.02 million, making it the 15th-largest in the United States. Its growth rate of 21.1% between 2010 and 2020 makes it one of the nation's fastest-growing large cities. Seattle is situated on an isthmus between Puget Sound (an inlet of the Pacific Ocean) and Lake Washington. It is the northernmost major city in the United States, located about south of the Canadian border. A major gateway for trade with East Asia, Seattle is the fourth-largest port in North America in terms of container handling . The Seattle area was inhabited by Native Americans for at least 4,000 years before the first permanent European settlers. Arthur A. Denny and his group of travelers, subsequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Ripple Marks
In folklore, giants (from Ancient Greek: ''gigas'', cognate giga-) are beings of human-like appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''giant'' is first attested in 1297 from Robert of Gloucester's chronicle. It is derived from the ''Gigantes'' ( grc-gre, Γίγαντες) of Greek mythology. Fairy tales such as ''Jack the Giant Killer'' have formed the modern perception of giants as dimwitted ogres, sometimes said to eat humans, while other giants tend to eat the livestock. The antagonist in ''Jack and the Beanstalk'' is often described as a giant. In some more recent portrayals, like those of Jonathan Swift and Roald Dahl, some giants are both intelligent and friendly. Literary and cultural analysis Giants appear in the folklore of cultures worldwide as they represent a relatively simple concept. Representing the human body enlarged to the point of being monstrous, giants evoke terror and remind humans of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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