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Pockmark (geology)
Pockmarks are concave, crater-like depressions on seabeds that are caused by fluids (liquids and gasses) escaping and erupting through the seafloor. They can vary in size and have been found worldwide. Pockmarks were discovered off the coasts of Nova Scotia, Canada in the late 1960s by Lew King and Brian McLean of the Bedford Institute of Oceanography, using a new side scan sonar developed in the late 1960s by Kelvin Hughes. Before the two researchers King and McLean used the side scan sonar, they had noticed 'notches' on echo sounder and shallow seismic records in the seafloor off Nova Scotia. They believed these notches to represent gullies and curvilinear troughs in the muddy seafloor. However, they could never work out how to join these notches from one survey line to the next. It was, therefore, not before they surveyed with the area-coverage system, Side scan sonar, that they realized the notches were in fact closed depressions (craters) and not curvilinear features. This was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nova Scotia
Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native English-speakers, and the province's population is 969,383 according to the 2021 Census. It is the most populous of Canada's Atlantic provinces. It is the country's second-most densely populated province and second-smallest province by area, both after Prince Edward Island. Its area of includes Cape Breton Island and 3,800 other coastal islands. The Nova Scotia peninsula is connected to the rest of North America by the Isthmus of Chignecto, on which the province's land border with New Brunswick is located. The province borders the Bay of Fundy and Gulf of Maine to the west and the Atlantic Ocean to the south and east, and is separated from Prince Edward Island and the island of Newfoundland by the Northumberland and Cabot straits, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedford Institute Of Oceanography
The Bedford Institute of Oceanography (BIO) is a major Government of Canada ocean research facility located in Dartmouth, Nova Scotia. BIO is the largest ocean research station in Canada. Established in 1962 as Canada's first, and currently largest, federal centre for oceanographic research, BIO derives its name from the Bedford Basin, an inland bay comprising the northern part of Halifax Harbour, upon which it is located. Spread out over 40 acres (160,000 m2) of a former Royal Canadian Navy (RCN) property near Shannon Park in Dartmouth, BIO consists of a series of interconnected buildings housing research labs and offices, as well as docks for Canadian Coast Guard and RCN research vessels. As the federal government seeks to concentrate its operations in the Halifax Regional Municipality, BIO is being considered for additional office buildings to house other non-oceanographic and non-research organizations and their employees. As such, new buildings have been built for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Side Scan Sonar
Side-scan sonar (also sometimes called side scan sonar, sidescan sonar, side imaging sonar, side-imaging sonar and bottom classification sonar) is a category of sonar system that is used to efficiently create an image of large areas of the sea floor. Uses Side-scan sonar may be used to conduct surveys for marine archaeology; in conjunction with seafloor samples it is able to provide an understanding of the differences in material and texture type of the seabed. Side-scan sonar imagery is also a commonly used tool to detect debris items and other obstructions on the seafloor that may be hazardous to shipping or to seafloor installations by the oil and gas industry. In addition, the status of pipelines and cables on the seafloor can be investigated using side-scan sonar. Side-scan data are frequently acquired along with bathymetric soundings and sub-bottom profiler data, thus providing a glimpse of the shallow structure of the seabed. Side-scan sonar is also used for fisheries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin Hughes
Hensoldt UK, formerly Kelvin Hughes, is a British company specialising in the design and manufacture of navigation and surveillance systems and a supplier of navigational data to both the commercial marine and government marketplace. The company provides radar systems to navies, governments, coastlines, ports and VTS installations as well as radars for land based security and surveillance applications. Part of Kelvin Hughes' history includes producing the first Type Approved commercial radar in 1947 as well as the first paper chart tracing service in 1971. Modern day products that Kelvin Hughes sell include SharpEye™, a solid state radar with clutter management and Doppler processing. History The Kelvin connection The Kelvin connection is based upon the professional relationship between William Thomson (later-Lord Kelvin) (1824–1907), Professor of Natural Philosophy at Glasgow University from 1846–1899 and James White (1824–1884), a Glasgow-based Optical Instrument ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or exemplified by the odors of gasoline and lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases (such as methane and propane), liquids (such as hexane and benzene), low melting solids (such as paraffin wax and naphthalene) or polymers (such as polyethylene and polystyrene). In the fossil fuel industries, ''hydrocarbon'' refers to the naturally occurring petroleum, natural gas and coal, and to their hydrocarbon derivatives and purified forms. Combustion of hydrocarbons is the main source of the world's energy. Petroleum is the dominant raw-material source for organic commodity chemicals such as solvents and polymers. Most anthropogenic (human-generated) emissions of greenhouse gases are carbon di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroleum Reservoir
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence of high heat and pressure in the Earth's crust. Petroleum reservoirs are broadly classified as ''conventional'' and '' unconventional'' reservoirs. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability, while in unconventional reservoirs, the rocks have high porosity and low permeability, which keeps the hydrocarbons trapped in place, therefore not requiring a cap rock. Reservoirs are found using hydrocarbon exploration methods. Oil field An oil field is an area of accumulation of liquid oil underground in multiple (potentially linked) reservoirs, trapped as it rises by impermeable rock formations. In industrial terms, an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Seeps
A cold seep (sometimes called a cold vent) is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool. ''Cold'' does not mean that the temperature of the seepage is lower than that of the surrounding sea water. On the contrary, its temperature is often slightly higher. The "cold" is relative to the very warm (at least ) conditions of a hydrothermal vent. Cold seeps constitute a biome supporting several endemism, endemic species. Cold seeps develop unique topography over time, where reactions between methane and seawater create carbonate rock formations and reefs. These reactions may also be dependent on bacterial activity. Ikaite, a hydrous calcium carbonate, can be associated with oxidizing methane at cold seeps. Types Types of cold seeps can be distinguished according to the depth, as shallow cold seeps and deep cold seeps. Cold seeps can also be distinguished in detail, as follows: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limnic Eruption
A limnic eruption, also known as a lake overturn, is a very rare type of natural disaster in which dissolved carbon dioxide () suddenly erupts from deep lake waters, forming a gas cloud capable of suffocating wildlife, livestock, and humans. A limnic eruption may also cause tsunami or seiche as the rising displaces water. Scientists believe earthquakes, volcanic activity, and other explosive events can serve as triggers for limnic eruptions. Lakes in which such activity occurs are referred to as limnically active lakes or exploding lakes. Some features of limnically active lakes include: * -saturated incoming water * A cool lake bottom indicating an absence of direct volcanic interaction with lake waters * An upper and lower thermal layer with differing saturations * Proximity to areas with volcanic activity Investigations of the Lake Monoun and Lake Nyos casualties led scientists to classify limnic eruptions as a distinct type of disaster event, even though they can be indirect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal Fish
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word ''demersal'' comes from the Latin ''demergere'', which means ''to sink''. Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column. Demersal fish fillets contain little fish oil (one to four percent), whereas pelagic fish can contain up to 30 percent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentology
Sedimentology encompasses the study of modern sediments such as sand, silt, and clay, and the processes that result in their formation (erosion and weathering), transport, deposition and diagenesis. Sedimentologists apply their understanding of modern processes to interpret geologic history through observations of sedimentary rocks and sedimentary structures. Sedimentary rocks cover up to 75% of the Earth's surface, record much of the Earth's history, and harbor the fossil record. Sedimentology is closely linked to stratigraphy, the study of the physical and temporal relationships between rock layers or strata. The premise that the processes affecting the earth today are the same as in the past is the basis for determining how sedimentary features in the rock record were formed. By comparing similar features today to features in the rock record—for example, by comparing modern sand dunes to dunes preserved in ancient aeolian sandstones—geologists reconstruct past environmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanography
Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers utilize to glean further knowledge of the world ocean, including astronomy, biology, chemistry, climatology, geography, geology, hydrology, meteorology and physics. Paleoceanography studies the history of the oceans in the geologic past. An oceanographer is a person who studies many matters concerned with oceans, including marine geology, physics, chemistry and biology. History Early history Humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
