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Geographic Names Information System
The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of the Marshall Islands, Federated States of Micronesia, and Palau. It is a type of gazetteer. It was developed by the United States Geological Survey (USGS) in cooperation with the United States Board on Geographic Names (BGN) to promote the standardization of feature names. Data were collected in two phases. Although a third phase was considered, which would have handled name changes where local usages differed from maps, it was never begun. The database is part of a system that includes topographic map names and bibliographic references. The names of books and historic maps that confirm the feature or place name are cited. Variant names, alternatives to official federal names for a feature, are also recorded. Each feature receives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USGS Logo Green
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredth anniversa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Flow
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Delta
A river delta is a landform shaped like a triangle, created by deposition of sediment that is carried by a river and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment. It is so named because its triangle shape resembles the Greek letter Delta. The size and shape of a delta is controlled by the balance between watershed processes that supply sediment, and receiving basin processes that redistribute, sequester, and export that sediment. The size, geometry, and location of the receiving basin also plays an important role in delta evolution. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide coastline defense and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape posit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial Fan
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than to almost . Alluvial fans typically form where flow emerges from a confined channel and is free to spread out and infiltrate the surface. This reduces the carrying capacity of the flow and results in deposition of sediments. The flow can take the form of infrequent debris flows or one or more ephemeral or perennial streams. Alluvial fans are common in the geologic record, such as in the Triassic basins of eastern North America and the New Red Sandstone of south Devon. Such fan deposits likely contain the largest accumulations of gravel in the geologic record. Alluvial fans have also been found on Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Olive (other)
Mount Olive may refer to: Places Canada *Mount Olive-Silverstone-Jamestown, a neighbourhood in Toronto, Ontario *Mount Olive (Canadian Rockies), a mountain on the Continental Divide/British Columbia-Alberta in the Canadian Rockies United States Cities and towns * Mount Olive, Alabama (other) * Mount Olive, Arkansas (other) * Mount Olive, Illinois * Mount Olive, Indiana * Mount Olive, Kentucky * Mount Olive, Mississippi * Mount Olive, Missouri *Mount Olive, Stokes County, North Carolina *Mount Olive, Wayne County, North Carolina *Mount Olive, Ohio *Mount Olive, Shenandoah County, Virginia *Mount Olive Township, New Jersey Other places in the US * Mount Olive Cemetery, in Chicago *Mount Olive (Natchez, Mississippi), a historic house * Mount Olive Cemetery, in Middletown New Jersey Other uses *Mount Olive College, located in Mount Olive, North Carolina *Mount Olive Pickle Company, a food processing firm See also *Mount of Olives *''Mountolive'' *Mount Olivet (dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Saint Helens
Mount St. Helens (known as Lawetlat'la to the indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It lies northeast of Portland, Oregon, and south of Seattle. Mount St. Helens takes its English name from that of the British diplomat Lord St Helens, a friend of explorer George Vancouver who surveyed the area in the late 18th century. The volcano is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire. The Mount St. Helens major eruption of May 18, 1980 remains the deadliest and most economically destructive volcanic event in U.S. history. Fifty-seven people were killed; 200 homes, 47 bridges, of railways, and of highway were destroyed. A massive debris avalanche, triggered by a magnitude 5.1 earthquake, caused a lateral eruption that reduced the elevation of the mountain' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diacritic
A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacritic'' is a noun, though it is sometimes used in an attributive sense, whereas ''diacritical'' is only an adjective. Some diacritics, such as the acute ( ◌́ ) and grave ( ◌̀ ), are often called ''accents''. Diacritics may appear above or below a letter or in some other position such as within the letter or between two letters. The main use of diacritics in Latin script is to change the sound-values of the letters to which they are added. Historically, English has used the diaeresis diacritic to indicate the correct pronunciation of ambiguous words, such as "coöperate", without which the letter sequence could be misinterpreted to be pronounced . Other examples are the acute and grave accents, which can i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contour Line
A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function f(x,y) parallel to the (x,y)-plane. More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value. In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes. The contour interval of a contour map is the difference in elevation between successive contour lines. The gradient of the function is always perpendicular to the contour lines. When the lines are close together the magnitude of the grad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpolation
In the mathematical field of numerical analysis, interpolation is a type of estimation, a method of constructing (finding) new data points based on the range of a discrete set of known data points. In engineering and science, one often has a number of data points, obtained by sampling or experimentation, which represent the values of a function for a limited number of values of the independent variable. It is often required to interpolate; that is, estimate the value of that function for an intermediate value of the independent variable. A closely related problem is the approximation of a complicated function by a simple function. Suppose the formula for some given function is known, but too complicated to evaluate efficiently. A few data points from the original function can be interpolated to produce a simpler function which is still fairly close to the original. The resulting gain in simplicity may outweigh the loss from interpolation error and give better performance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foot (unit)
The foot ( feet), standard symbol: ft, is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, , is a customarily used alternative symbol. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meters exactly. In both customary and imperial units, one foot comprises 12 inches and one yard comprises three feet. Historically the "foot" was a part of many local systems of units, including the Greek, Roman, Chinese, French, and English systems. It varied in length from country to country, from city to city, and sometimes from trade to trade. Its length was usually between 250 mm and 335 mm and was generally, but not always, subdivided into 12 inches or 16 digits. The United States is the only industrialized nation that uses the international foot and the survey foot (a customary unit of length) in preference to the meter in its commercial, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cayuga Lake
Cayuga Lake (,,) is the longest of central New York's glacial Finger Lakes, and is the second largest in surface area (marginally smaller than Seneca Lake) and second largest in volume. It is just under long. Its average width is , and it is at its widest point, near Aurora. It is approximately at its deepest point, and has over of shoreline. The lake is named after the indigenous Cayuga people. Location The city of Ithaca, site of Ithaca College and Cornell University, is located at the southern end of Cayuga Lake. Villages and settlements along the east shore of Cayuga Lake include Myers, King Ferry, Aurora, Levanna, Union Springs, and Cayuga. Settlements along the west shore of the lake include Sheldrake, Poplar Beach, and Canoga. The lake has two small islands. One is near Union Springs, called Frontenac Island (northeast); this island is not inhabited. The other island, Canoga Island (northwest), is located near the town of Canoga. This island has several ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Corps Of Engineers
, colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = Lieutenant general (United States), LTG Scott A. Spellmon , commander1_label = List of United States Army Corps of Engineers Chiefs of Engineers, Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers , commander2 = Major general (United States), MG]Richard J. Heitkamp, commander2_label = Deputy Chief of Engineers and Deputy Commanding General , commander3 = Major general (United States), MGKimberly M. Colloton, commander3_label = Deputy Commanding General for Military and International Operations , commander4 = Major general (United States), MG]William H. Graham, commander4_label = Deputy Command ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
