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Submarine Pipeline
A submarine pipeline (also known as marine, subsea or offshore pipeline) is a pipeline that is laid on the seabed or below it inside a trench.Dean, p. 338-340Gerwick, p. 583-585 In some cases, the pipeline is mostly on-land but in places it crosses water expanses, such as small seas, straits and rivers.Palmer & King, p. 2-3 Submarine pipelines are used primarily to carry oil or gas, but transportation of water is also important. A distinction is sometimes made between a ''flowline'' and a pipeline.Bai & Bai, p. 22 The former is an ''intrafield'' pipeline, in the sense that it is used to connect subsea wellheads, manifolds and the platform ''within'' a particular development field. The latter, sometimes referred to as an ''export pipeline'', is used to bring the resource to shore. Sizeable pipeline construction projects need to take into account many factors, such as the offshore ecology, geohazards and environmental loading – they are often undertaken by multidisciplinary, interna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipeline Transport
Pipeline transport is the long-distance transportation of a liquid or gas through a system of pipes—a pipeline—typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries of the world. The United States had 65%, Russia had 8%, and Canada had 3%, thus 76% of all pipeline were in these three countries. ''Pipeline and Gas Journals worldwide survey figures indicate that of pipelines are planned and under construction. Of these, represent projects in the planning and design phase; reflect pipelines in various stages of construction. Liquids and gases are transported in pipelines, and any chemically stable substance can be sent through a pipeline. Pipelines exist for the transport of crude and refined petroleum, fuels – such as oil, natural gas and biofuels – and other fluids including sewage, slurry, water, beer, hot water or steam for shorter distances. Pipelines are useful for transporting water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Landslide
Submarine landslides are marine landslides that transport sediment across the continental shelf and into the deep ocean. A submarine landslide is initiated when the downwards driving stress (gravity and other factors) exceeds the resisting stress of the seafloor slope material, causing movements along one or more concave to planar rupture surfaces. Submarine landslides take place in a variety of different settings, including planes as low as 1°, and can cause significant damage to both life and property. Recent advances have been made in understanding the nature and processes of submarine landslides through the use of sidescan sonar and other seafloor mapping technology.Hampton, M & Locat, J (1996) Submarine landslides. Reviews of Geophysics, 34, 33–59.Locat, J & Lee, HJ (2002) Submarine landslides: Advances and challenges. Canadian Geotechnical Journal, 39, 193.Mason, D, Habitz, C, Wynn, R, Pederson, G & Lovholt, F (2006) Submarine landslides: processes, triggers and hazar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammunition
Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other weapons that create the effect on a target (e.g., bullets and warheads). The purpose of ammunition is to project a force against a selected target to have an effect (usually, but not always, lethal). An example of ammunition is the firearm cartridge, which includes all components required to deliver the weapon effect in a single package. Until the 20th century, black powder was the most common propellant used but has now been replaced in nearly all cases by modern compounds. Ammunition comes in a great range of sizes and types and is often designed to work only in specific weapons systems. However, there are internationally recognized standards for certain ammunition types (e.g., 5.56×45mm NATO) that enable their use across different weapo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Mine
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered. Although international law requires signatory nations to declare mined areas, precise locations remain secret; and non-complying individ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor
An anchor is a device, normally made of metal , used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ''ancora'', which itself comes from the Greek ἄγκυρα (ankȳra). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimise drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea.. Overview Anchors achieve holding power either by "hooking" into the seabed, or mass, or a combination of the two. Permanent moorings use large masses (common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Vessel
A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was estimated to be about 4.6 million, unchanged from 2014. The fleet in Asia was the largest, consisting of 3.5 million vessels, accounting for 75 percent of the global fleet. In Africa and North America the estimated number of vessels declined from 2014 by just over 30,000 and by nearly 5,000, respectively. For Asia, Latin America and the Caribbean and Oceania the numbers all increased, largely as a result of improvements in estimation procedures.FAO 2007 It is difficult to estimate the number of recreational fishing boats. They range in size from small dinghies to large charter cruisers, and unlike commercial fishing vessels, are often not dedicated just to fishing. Prior to the 1950s there was little standardisation of fishing boats. Desig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strudel (ice)
A strudel (plural: strudel)https://en.wiktionary.org/wiki/Strudel. This plural form was recommended, and used, by E. Reimnitz and his colleagues. is a vertical hole in sea ice through which downward jet-like, buoyancy-driven drainage of flood water is thought to occur.Reimnitz, E. and Bruder, K.F., 1972. River discharge into an ice-covered ocean and related sediment dispersal, Beaufort Sea, Coast of Alaska. Geological Society of America Bulletin, 83(3): 861-866.Walker, H.J., 1973. Salinity changes in the Colville River delta, Alaska, during breakup, International Symposia on the Role of Snow and Ice in Hydrology, Symposium on Properties and Processes, Banff, Canada, pp. 514-527. This feature is less than a few tens of meters in size and typically occurs within 30 km from a river mouth, in the sea ice expanse that is fastened to the coastline (known as ''fast ice'').Reimnitz, E., Rodeick, C.A. and Wolf, S.C., 1974. Strudel scour: A unique marine geological phenomenon. Jour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stamukha
A stamukha (plural: ''stamukhi''; from Russian стамуха) is a grounded accumulation of sea ice rubble that typically develops along the boundary between fast ice and the drifting pack ice, or becomes incorporated into the fast ice.Barnes, P.W., D., McDowell & Reimnitz, E. (1978). Ice gouging characteristics: Their changing patterns from 1975-1977, Beaufort Sea, Alaska. United States Department of the Interior, Geological Survey Open File Report 78-730, Menlo Park, U.S.A., 42 p.Ogorodov, S.A. & Arkhipov, V.V. (2010) Caspian Sea bottom scouring by hummocky ice floes. Doklady Earth Sciences, 432, 1, pp. 703-707.Davies, T. A., Bell, T., Cooper, A. K., Josenhans, H., Polyak, L., Solheim, A., Stoker, M. S. & Stravers, J. A. (1997). Glaciated continental margins: An atlas of acoustic images. N.Y.: Chapman & Hall, p. 312. It is a pressure ridge. Wind, currents and tides contribute to this phenomenon. Stamukhi tend to occur in belts that are parallel to the shoreli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabed Gouging By Ice
Seabed gouging by ice is a process that occurs when floating ice features (typically icebergs and Pressure ridge (ice), sea ice ridges) drift into shallower areas and their keel comes into contact with the seabed.King 2011Palmer & Been 2011Barrette 2011 As they keep drifting, they produce long, narrow furrows most often called ''gouges'', or ''scours''.Wadhams 2000, p. 72Weeks 2010, Ch. 13 This phenomenon is common in offshore environments where ice is known to exist. Although it also occurs in rivers and lakes,Noble and Comfort 1982Grass 1984 it appears to be better documented from oceans and sea expanses.Palmer & Been 2011Wadhams 2000, p. 72Weeks 2010, Ch. 13 Seabed scours produced via this mechanism should not be confused with Strudel (ice)#Strudel scours, strudel scours. These result from spring run-off water flowing onto the surface of a given sea ice expanse, which eventually drains away through cracks, seal breathing holes, etc. The resulting turbulence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tidal Scour
Tidal scour is “sea-floor erosion caused by strong tidal currents resulting in the removal of inshore sediments and formation of deep holes and channels”. Examples of this hydrological process can be found globally. Two locations in the United States where tidal scour is the predominant shaping force is the San Francisco Bay and the Elkhorn Slough.Silberstein 1989 M, Campbell E. 1989. Elkhorn Slough. Monterey, CA: Monterey Bay Aquarium. 64 p. Tidal force can also contribute to bridge scour. Historical Perspective and Relevance Research on tidal scour is largely centered at Elkhorn Slough in California. The slough was directly exposed to tidal flux beginning in 1947 with the creation of the Moss Landing Harbor. Multiple studies have been done on the slough since tidal exposure to catalog the morphological change and determine how long it will take for the system to reach equilibrium. Formation Tidal Scours are formed in tide-dominated deltas and estuaries with the changing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave
In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (resting) value at some frequency. When the entire waveform moves in one direction, it is said to be a ''traveling wave''; by contrast, a pair of superimposed periodic waves traveling in opposite directions makes a '' standing wave''. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. Waves are often described by a ''wave equation'' (standing wave field of two opposite waves) or a one-way wave equation for single wave propagation in a defined direction. Two types of waves are most commonly studied in classical physics. In a ''mechanical wave'', stress and strain fields oscillate about a mechanical equilibrium. A mechanical wave is a local deformation (strain) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
