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Sand Banks
In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body of water close to the surface or above it, which poses a danger to navigation. Shoals are also known as sandbanks, sandbars, or gravelbars. Two or more shoals that are either separated by shared troughs or interconnected by past or present sedimentary and hydrographic processes are referred to as a shoal complex.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 term ''shoal'' is also used in a number of ways that can be either similar to, or quite different from, how it is used in geologic, geomorphic, and oceanographic literature. Sometimes, the term refers to either any relatively shallow place in a stream, lake, sea, or other body of water; a rocky area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deposition (sediment)
Deposition is the geological process in which sediments, soil and rock (geology), rocks are added to a landform or landmass. Wind, ice, water, and gravity Transportation (sediment), transport previously Weathering, weathered surface material, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of sediment. This occurs when the forces responsible for sediment transportation are no longer sufficient to overcome the forces of gravity and friction, creating a resistance to motion; this is known as the null-point hypothesis. Deposition can also refer to the buildup of sediment from Organic matter, organically derived matter or chemical processes. For example, chalk is made up partly of the microscopic calcium carbonate skeletons of marine plankton, the deposition of which induced chemical processes (diagenesis) to deposit further calcium carbonate. Similarly, the formation of coal begins with the deposition of organic material, mainly from plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrier Island
Barrier islands are a Coast#Landforms, coastal landform, a type of dune, dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers, with islands periodically separated by tidal inlets. The longest barrier island in the world is Padre Island of Texas, United States, at long. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula, often including a beach, barrier beach. Though many are long and narrow, the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave ener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landform
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Delta
A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the '' river mouth'', where the river merges into an ocean, a sea, or an estuary, into a lake, a reservoir, or (more rarely) into another river that cannot carry away the sediment supplied by the feeding river. Etymologically, the term ''river delta'' derives from the triangular shape (Δ) of the uppercase Greek letter delta. In hydrology, the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Mouth
A river mouth is where a river flows into a larger body of water, such as another river, a lake/reservoir, a bay/gulf, a sea, or an ocean. At the river mouth, sediments are often deposited due to the slowing of the current, reducing the carrying capacity of the water. The water from a river can enter the receiving body in a variety of different ways. The motion of a river is influenced by the relative density of the river compared to the receiving water, the rotation of the Earth, and any ambient motion in the receiving water, such as tides or seiches. If the river water has a higher density than the surface of the receiving water, the river water will plunge below the surface. The river water will then either form an underflow or an interflow within the lake. However, if the river water is lighter than the receiving water, as is typically the case when fresh river water flows into the sea, the river water will float along the surface of the receiving water as an overflow. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish Water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary, estuaries, or it may occur in brackish Fossil water, fossil aquifers. The word comes from the Middle Dutch root '':wikt:brak#Dutch, brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the Osmotic power, salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it can be damaging to the environment (see article on shrimp farming, shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') and ''atoll lagoons''. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as Estuary, estuaries. Lagoons are common coastal features around many parts of the world. Definition and terminology Lagoons are shallow, often elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, reef, coral reef, or similar feature. Some authorities include fresh water bodies in the definition of "lagoon", while others explicitly restrict "lagoon" to bodies of water with some degree of salinity. The distinction between "lagoon" and "estuary" also varies between authorities. Richard A. Davis J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvial
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. Sediment or alluvium carried by rivers shapes the landscape a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Bank
An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the seabed that is shallow compared to its surrounding area, such as a shoal or the top of an underwater hill. Somewhat like continental slopes, ocean bank slopes can upwell as tidal and other flows intercept them, sometimes resulting in nutrient-rich currents. Because of this, some large banks, such as Dogger Bank and the Grand Banks of Newfoundland, are among the richest fishing grounds in the world. There are some banks that were reported in the 19th century by navigators, such as Wachusett Reef, whose existence is doubtful. Types Ocean banks may be of volcanic nature. Banks may be carbonate or terrigenous. In tropical areas some banks are submerged atolls. As they are not associated with any landmass, banks have no outside source of sediments. Carbonate banks are typically platforms, rising from the ocean depths, whereas terrigenous banks are elevated sedimentary deposits. Sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coast
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, such as that caused by wind wave, waves. The geology, geological composition of rock (geology), rock and soil dictates the type of shore that is created. Earth has about of coastline. Coasts are important zones in natural ecosystems, often home to a wide range of biodiversity. On land, they harbor ecosystems, such as freshwater marsh, freshwater or estuary, estuarine wetlands, that are important for birds and other terrestrial animals. In wave-protected areas, coasts harbor salt marshes, mangroves, and seagrass meadow, seagrasses, all of which can provide nursery habitat for finfish, shellfish, and other aquatic animals. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessility (motility), sessile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltaic Lobe
A deltaic lobe is a wetland formation that forms as a river empties water and sediment into other bodies of water. As the sediment builds up from this delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ..., the river will break away from its single channel and the mouth will be pushed outwards, forming a deltaic lobe.David E. Frazier. "Recent Deltaic Deposits of Mississippi River: Their Development and Chronology: ABSTRACT." ''AAPG Bulletin'', vol. 51, 1967, doi:10.1306/5d25c219-16c1-11d7-8645000102c1865d. When the rate of water discharge and lobe progradation are sufficiently high, a river can form a deltaic lobe. A single deltaic lobe includes a network of shallow channels called distributaries that make up a distributary network that branches off from the mainstream of the ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
