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Seabed

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Common stingrayforaging forinvertebratesinseafloor sediment.
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Theseabed(also known as theseafloor,sea floor,ocean floor,andocean bottom) is the bottom of theocean.All floors of the ocean are known as 'seabeds'.

The structure of the seabed of the global ocean is governed byplate tectonics.Most of the ocean is very deep, where the seabed is known as theabyssal plain.Seafloor spreading creates mid-ocean ridges along the center line of major ocean basins, where the seabed is slightly shallower than the surrounding abyssal plain. From the abyssal plain, the seabed slopes upward toward the continents and becomes, in order from deep to shallow, thecontinental rise,slope,andshelf.The depth within the seabed itself, such as the depth down through asediment core,is known as the "depth below seafloor". The ecological environment of the seabed and the deepest waters are collectively known, as ahabitatfor creatures, as the "benthos".

Most of the seabed throughout the world's oceans is covered in layers ofmarine sediments.Categorized by where the materials come from or composition, these sediments are classified as either: from land (terrigenous), from biological organisms (biogenous), from chemical reactions (hydrogenous), and from space (cosmogenous). Categorized by size, these sediments range from very small particles calledclaysandsilts,known as mud, to larger particles fromsandtoboulders.

Features of the seabed are governed by the physics ofsediment transportand by the biology of the creatures living in the seabed and in the ocean waters above. Physically, seabed sediments often come from theerosionof material on land and from other rarer sources, such asvolcanic ash.Sea currents transport sediments, especially in shallow waters wheretidal energyandwaveenergy cause resuspension of seabed sediments. Biologically, microorganisms living within the seabed sediments change seabed chemistry. Marine organisms create sediments, both within the seabed and in the water above. For example,phytoplanktonwith silicate or calcium carbonate shells grow in abundance in the upper ocean, and when they die, their shells sink to the seafloor to become seabed sediments.

Human impacts on the seabed are diverse. Examples of human effects on the seabed include exploration, plastic pollution, and exploitation by mining anddredgingoperations. To map the seabed, ships useacoustic technologyto map water depths throughout the world. Submersible vehicles help researchers study unique seabed ecosystems such ashydrothermal vents.Plastic pollutionis a global phenomenon, and because the ocean is the ultimate destination for global waterways, much of the world's plastic ends up in the ocean and some sinks to the seabed. Exploitation of the seabed involves extracting valuable minerals fromsulfide depositsvia deep sea mining, as well as dredging sand from shallow environments for construction andbeach nourishment.

Structure

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See also:Seafloor spreading
Bathymetryof the ocean floor showing thecontinental shelvesandoceanic plateaus(red), themid-ocean ridges(yellow-green) and theabyssal plains(blue to purple). Like land terrain, the ocean floor has mountains including volcanoes, ridges, valleys, and plains.
Drawing showing divisions according to depth and distance from shore
The major oceanic divisions

Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources. The structure of the oceans, starting with the continents, begins usually with acontinental shelf,continues to thecontinental slope– which is a steep descent into the ocean, until reaching theabyssal plain– a topographicplain,the beginning of the seabed, and its main area. The border between the continental slope and the abyssal plain usually has a more gradual descent, and is called thecontinental rise,which is caused bysedimentcascading down the continental slope.[citation needed]

Themid-ocean ridge,as its name implies, is a mountainous rise through the middle of all the oceans, between the continents. Typically ariftruns along the edge of this ridge. Alongtectonic plateedges there are typicallyoceanic trenches– deep valleys, created by the mantle circulation movement from the mid-ocean mountain ridge to the oceanic trench.[1]

Hotspotvolcanic island ridges are created by volcanic activity, erupting periodically, as the tectonic plates pass over a hotspot. In areas with volcanic activity and in the oceanic trenches there arehydrothermal vents– releasing high pressure and extremely hot water and chemicals into the typically freezing water around it.

Deep ocean water is divided into layers or zones, each with typical features of salinity, pressure, temperature andmarine life,according to their depth. Lying along the top of theabyssal plainis theabyssal zone,whose lower boundary lies at about 6,000 m (20,000 ft). Thehadal zone– which includes the oceanic trenches, lies between 6,000 and 11,000 metres (20,000–36,000 ft) and is the deepest oceanic zone.[2][3]

Depth below seafloor

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Depth below seaflooris avertical coordinateused in geology,paleontology,oceanography,andpetrology(seeocean drilling). Theacronym"mbsf" (meaning "meters below the seafloor" ) is a common convention used for depths below the seafloor.[4][5]

  • Different seabeds in the world's oceans
  • gravel seabed in Italy
    gravel seabed in Italy
  • white sand seabed in Mexico
    white sand seabed in Mexico
  • sand seabed in Greece
    sand seabed in Greece
  • hydrothermal vents
    hydrothermal vents

Sediments

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Main article:Marine sediment
Total sediment thickness of the world's oceans andcontinental marginsin meters.

Sediments in the seabedvary in origin, from eroded land materials carried into the ocean by rivers or wind flow, waste and decompositions of sea creatures, and precipitation of chemicals within the sea water itself, including some from outer space.[6]There are four basic types of sediment of the sea floor:

  1. Terrigenous(alsolithogenous) describes the sediment from continents eroded by rain, rivers, and glaciers, as well as sediment blown into the ocean by the wind, such as dust and volcanic ash.
  2. Biogenousmaterial is the sediment made up of the hard parts of sea creatures, mainlyphytoplankton,that accumulate on the bottom of the ocean.
  3. Hydrogenoussediment is material that precipitates in the ocean when oceanic conditions change, or material created inhydrothermal ventsystems.
  4. Cosmogenoussediment comes from extraterrestrial sources.[7]

Terrigenous and biogenous

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Satellite image of wind-blown mineral dust over the Atlantic. Dust may become terrigenous sediment on the seabed.
Phytoplankton grow shells which later sink to the seabed to become biogenous sediments. For example,diatomsmakesilicateshells, which become siliceous ooze.

Terrigenous sedimentis the most abundant sediment found on the seafloor. Terrigenous sediments come from the continents. These materials are eroded from continents and transported by wind and water to the ocean. Fluvial sediments are transported from land by rivers and glaciers, such as clay, silt, mud, and glacial flour. Aeolian sediments are transported by wind, such as dust and volcanic ash.[8]

Biogenous sediment is the next most abundant material on the seafloor. Biogenous sediments are biologically produced by living creatures. Sediments made up of at least 30% biogenous material are called "oozes." There are two types of oozes: Calcareous oozes and Siliceous oozes.Planktongrow in ocean waters and create the materials that become oozes on the seabed. Calcareous oozes are predominantly composed of calcium shells found in phytoplankton such as coccolithophores and zooplankton like the foraminiferans. These calcareous oozes are never found deeper than about 4,000 to 5,000 meters because at further depths the calcium dissolves.[9]Similarly, Siliceous oozes are dominated by the siliceous shells of phytoplankton like diatoms and zooplankton such as radiolarians. Depending on the productivity of these planktonic organisms, the shell material that collects when these organisms die may build up at a rate anywhere from 1 mm to 1 cm every 1000 years.[9]

Hydrogenous and cosmogenous

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Hydrothermal vent fluids cause chemical reactions that precipitate out minerals that form sediments on the surrounding seafloor.

Hydrogenous sediments are uncommon. They only occur with changes in oceanic conditions such as temperature and pressure. Rarer still are cosmogenous sediments. Hydrogenous sediments are formed from dissolved chemicals that precipitate from the ocean water, or along the mid-ocean ridges, they can form by metallic elements binding onto rocks that have water of more than 300 °C circulating around them. When these elements mix with the cold sea water they precipitate from the cooling water.[9]Known asmanganese nodules,they are composed of layers of different metals like manganese, iron, nickel, cobalt, and copper, and they are always found on the surface of the ocean floor.[9]

Cosmogenous sediments are the remains of space debris such as comets and asteroids, made up of silicates and various metals that have impacted the Earth.[10]

Size classification

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Sedimenttypes from theSouthern Oceanshowing many different grain sizes: A) gravel and sand, B) gravel, C) bioturbated mud and sand, and D) laminated clays and silts.[11]

Another way that sediments are described is through their descriptive classification. These sediments vary in size, anywhere from 1/4096 of a mm to greater than 256 mm. The different types are: boulder, cobble, pebble, granule, sand, silt, and clay, each type becoming finer in grain. The grain size indicates the type of sediment and the environment in which it was created. Larger grains sink faster and can only be pushed by rapid flowing water (high energy environment) whereas small grains sink very slowly and can be suspended by slight water movement, accumulating in conditions where water is not moving so quickly.[12]This means that larger grains of sediment may come together in higher energy conditions and smaller grains in lower energy conditions.

Benthos

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This section is an excerpt fromBenthos.[edit]
Seaweedand twochitonsin atide pool

Benthos(fromAncient Greekβένθος(bénthos)'the depths [of the sea]'), also known as benthon, is thecommunityoforganismsthat live on, in, or near the bottom of a sea,river,lake,orstream,also known as thebenthic zone.[13]This community lives in or near marine or freshwatersedimentary environments,fromtidal poolsalong theforeshore,out to thecontinental shelf,and then down to theabyssal depths.

Many organisms adapted to deep-water pressure cannot survive in the upper parts of thewater column.The pressure difference can be very significant (approximately oneatmospherefor every 10 metres of water depth).[14]

Because light isabsorbedbefore it can reach deep ocean water, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column that drifts down to the depths. Thisdead and decaying mattersustains the benthicfood chain;most organisms in the benthic zone arescavengersordetritivores.

The termbenthos,coined byHaeckelin 1891,[15]comes from theGreeknounβένθος'depth of the sea'.[13][16]Benthosis used infreshwater biologyto refer to organisms at the bottom of freshwaterbodies of water,such as lakes, rivers, and streams.[17]There is also a redundant synonym,Benton.[18]

Topography

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See also:BathymetryandOcean surface topography
World map with ocean topography

Seabed topography(ocean topographyormarine topography) refers to the shape of the land (topography) when it interfaces with the ocean. These shapes are obvious along coastlines, but they occur also in significant ways underwater. The effectiveness of marine habitats is partially defined by these shapes, including the way they interact with and shapeocean currents,and the way sunlight diminishes when these landforms occupy increasing depths. Tidal networks depend on the balance between sedimentary processes and hydrodynamics however, anthropogenic influences can impact the natural system more than any physical driver.[19]

Marine topographies includecoastal and oceanic landformsranging from coastalestuariesandshorelinestocontinental shelvesandcoral reefs.Further out in the open ocean, they include underwater anddeep seafeatures such as ocean rises andseamounts.The submerged surface has mountainous features, including a globe-spanningmid-ocean ridgesystem, as well as underseavolcanoes,[20]oceanic trenches,submarine canyons,oceanic plateausandabyssal plains.

The mass of the oceans is approximately 1.35×1018metric tons,or about 1/4400 of the total mass of the Earth. The oceans cover an area of 3.618×108km2with a mean depth of 3,682 m, resulting in an estimated volume of 1.332×109km3.[21]

Features

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Layers of thepelagic zone

Each region of the seabed has typical features such as common sediment composition, typical topography, salinity of water layers above it, marine life, magnetic direction of rocks, andsedimentation.Some features of the seabed include flatabyssal plains,mid-ocean ridges,deeptrenches,andhydrothermal vents.

Seabed topography is flat where layers of sediments cover the tectonic features. For example, theabyssal plainregions of the ocean are relatively flat and covered in many layers of sediments.[22]Sediments in these flat areas come from various sources, including but not limited to: land erosion sediments from rivers, chemically precipitated sediments from hydrothermal vents,Microorganismactivity,sea currentseroding the seabed and transporting sediments to the deeper ocean, andphytoplanktonshell materials.

Where the seafloor is actively spreading and sedimentation is relatively light, such as in the northern and easternAtlantic Ocean,the original tectonic activity can be clearly seen as straight line "cracks" or "vents" thousands of kilometers long. These underwater mountain ranges are known asmid-ocean ridges.[7]

Other seabed environments include hydrothermal vents, cold seeps, and shallow areas. Marine life is abundant in thedeep seaaroundhydrothermal vents.[23]Largedeep sea communitiesof marine life have been discovered aroundblack and white smokers— vents emitting chemicals toxic to humans and mostvertebrates.This marine life receives its energy both from the extreme temperature difference (typically a drop of 150 degrees) and fromchemosynthesisbybacteria.Brine poolsare another seabed feature,[24]usually connected tocold seeps.In shallow areas, the seabed can host sediments created bymarine lifesuch as corals, fish, algae, crabs, marine plants and other organisms.

Human impact

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Exploration

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Main articles:Deep-sea explorationandOceanography § History
A video describing the operation and use of anautonomous landerin deep sea research.

The seabed has been explored by submersibles such asAlvinand, to some extent,scuba diverswith special equipment. Hydrothermal vents were discovered in 1977 by researchers using an underwater camera platform.[23]In recent years satellite measurements ofocean surface topographyshow very clearmaps of the seabed,[25]and these satellite-derived maps are used extensively in the study and exploration of the ocean floor.

Plastic pollution

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In 2020 scientists created what may be the first scientific estimate of how muchmicroplasticcurrently resides in Earth'sseafloor,after investigating six areas of ~3 km depth ~300 km off the Australian coast. They found the highly variable microplastic counts to be proportionate to plastic on the surface and the angle of the seafloor slope. By averaging the microplastic mass per cm3,they estimated that Earth's seafloor contains ~14 million tons of microplastic – about double the amount they estimated based on data from earlier studies – despite calling both estimates "conservative" as coastal areas are known to contain much moremicroplastic pollution.These estimates are about one to two times the amount of plastic thought – per Jambeck et al., 2015 – to currently enter the oceans annually.[26][27][28]

Exploitation

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This section is an excerpt fromDeep sea mining.[edit]
Schematic of a polymetallic nodule mining operation. From top to bottom, the three zoom-in panels illustrate the surface operation vessel, the midwater sediment plume, and the nodule collector operating on the seabed. The midwater plume comprises two stages: (i) the dynamic plume, in which the sediment-laden discharge water rapidly descends and dilutes to a neutral buoyancy depth, and (ii) the subsequent ambient plume that is advected by the ocean current and subject to background turbulence and settling.
Schematic of a polymetallic nodule mining operation. From top to bottom, the three zoom-in panels illustrate the surface operation vessel, the midwater sediment plume, and the nodule collector operating on the seabed. The midwater plume comprises two stages: (i) the dynamic plume, in which the sediment-laden discharge water rapidly descends and dilutes to a neutral buoyancy depth, and (ii) the subsequent ambient plume that is advected by the ocean current and subject to background turbulence and settling.[29]

Deep sea miningis the extraction of minerals from the seabed of thedeep sea.The main ores of commercial interest arepolymetallic nodules,which are found at depths of 4–6 km (2.5–3.7 mi) primarily on theabyssal plain.TheClarion-Clipperton Zone(CCZ) alone contains over 21 billion metric tons of these nodules, with minerals such ascopper,nickel,andcobaltmaking up 2.5% of their weight. It is estimated that the global ocean floor holds more than 120 million tons of cobalt, five times the amount found in terrestrial reserves.[30]

As of July 2024,only exploratory licenses have been issued, with no commercial-scale deep sea mining operations yet. TheInternational Seabed Authority(ISA) regulates all mineral-related activities ininternational watersand has granted 31 exploration licenses so far: 19 for polymetallic nodules, mostly in the CCZ; 7 for polymetallic sulphides inmid-ocean ridges;and 5 for cobalt-rich crusts in theWestern Pacific Ocean.[31]There is a push for deep sea mining to commence by 2025, when regulations by the ISA are expected to be completed.[32][33]

Deep sea mining is also possible in theexclusive economic zone(EEZ) of countries, such asNorway,where it has been approved.[34]In 2022, theCook IslandsSeabed Minerals Authority (SBMA) granted three exploration licenses for cobalt-rich polymetallic nodules within their EEZ.[35]Papua New Guineawas the first country to approve a deep sea mining permit for the Solwara 1 project, despite three independent reviews highlighting significant gaps and flaws in the environmental impact statement.[36]

The most common commercial model of deep sea mining proposed involves a caterpillar-track hydraulic collector and a riser lift system bringing the harvested ore to a production support vessel withdynamic positioning,and then depositing extra discharge down the water column. Related technologies include robotic mining machines, as surface ships, and offshore and onshore metal refineries.[37][38]Wind farms, solar energy,electric vehicles,and battery technologies use many of the deep-sea metals.[37]Electric vehicle batteriesare the main driver of the critical metals demand that incentivises deep sea mining.[citation needed]

Theenvironmental impactof deep sea mining is controversial.[39][40]Environmental advocacy groups such asGreenpeaceand the Deep Sea Mining Campaign[41]claimed that seabed mining has the potential to damagedeep sea ecosystemsand spread pollution from heavy metal-laden plumes.[42]Critics have called for moratoria[43][44]or permanent bans.[45]Opposition campaigns enlisted the support of some industry figures, including firms reliant on the target metals. Individual countries with significant deposits within theirexclusive economic zones (EEZ's)are exploring the subject.[46][47]

As of 2021, the majority of marine mining used dredging operations at depths of about 200 m, wheresand, silt and mud for construction purposesis abundant, along withmineral rich sandscontainingilmeniteand diamonds.[48][49]

In art and culture

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Some children's play songs include elements such as "There's a hole at the bottom of the sea", or "A sailor went to sea... but all that he could see was the bottom of the deep blue sea".

On and under the seabed are archaeological sites of historic interest, such as shipwrecks and sunken towns. This underwater cultural heritage is protected by theUNESCO Convention on the Protection of the Underwater Cultural Heritage.The convention aims at preventing looting and the destruction or loss of historic and cultural information by providing an international legal framework.[50]

See also

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References

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  1. ^Kump, Lee R.; Kasting, James F.; Crane, Robert G. (2010). "Chapter 7. Circulation of the Solid Earth".The Earth System(3rd ed.). New Jersey: Pearson Education, Inc. pp. 122–148.ISBN978-0-321-59779-3.
  2. ^"Open Ocean – Oceans, Coasts, and Seashores".National Park Service.U.S. Department of the Interior.Retrieved13 October2021.
  3. ^NOAA."Ocean floor features".National Oceanic and Atmospheric Administration.Retrieved13 October2021.
  4. ^Flood, Roger D.; Piper, D.J.W. (1997). "Preface: Depth Below Seafloor Conventions". In Flood; Piper; Klaus, A.; Peterson, L.C. (eds.).Proceedings of the Ocean Drilling Program, Scientific Results.Vol. 155. p. 3.doi:10.2973/odp.proc.sr.155.200.1997.we follow Ocean Drilling Program (ODP) meters below seafloor (mbsf) convention
  5. ^Parkes, R. John; Henrik Sass (2007). Barton, Larry L. (ed.).Sulphate-reducing bacteria environmental and engineered systems.Cambridge University Press. pp. 329–358.doi:10.1017/CBO9780511541490.012.ISBN978-0-521-85485-6.Retrieved11 June2010.metres below the seafloor (mbsf)
  6. ^Murray, Richard W. "Ocean-Floor Sediments,"Water Encyclopedia
  7. ^abChester, Roy; Jickells, Tim (2012). "Chapter 15. The components of marine sediments".Marine Geochemistry(3rd ed.). Blackwell Publishing Ltd. pp. 321–351.ISBN978-1-4051-8734-3.
  8. ^Chester, Roy; Jickells, Tim (2012). "Chapter 13. Marine sediments".Marine Geochemistry(3rd ed.). Blackwell Publishing Ltd. pp. 273–289.ISBN978-1-4051-8734-3.
  9. ^abcd"The Bottom of the Ocean,"Marine Science
  10. ^"Types of Marine Sediments",Article Myriad
  11. ^Grobe, Hannes; Kiekmann, Bernhard; Hillenbrand, Claus-Dieter."The memory of polar oceans"(PDF).AWI:37–45.
  12. ^Tripati, Aradhna, Lab 6-Marine Sediments, Marine Sediments Reading, E&SSCI15-1, UCLA, 2012
  13. ^abBenthosfrom the Census of Antarctic Marine Life website
  14. ^US Department of Commerce, National Oceanic and Atmospheric Administration."How does pressure change with ocean depth?".oceanservice.NOAA.gov.
  15. ^Haeckel, E. 1891. Plankton-Studien. Jenaische Zeitschrift für Naturwissenschaft 25 / (Neue Folge)18: 232-336.BHL.
  16. ^βένθος.Liddell, Henry George;Scott, Robert;A Greek–English Lexiconat thePerseus Project.
  17. ^"North American Benthological Society website".Archived fromthe originalon 2008-07-05.Retrieved2008-08-16.
  18. ^Nehring, S. & Albrecht, U. (1997).Benthos und das redundant Benton: Neologismen in der deutschsprachigen Limnologie.Lauterbornia31: 17-30,[1].
  19. ^Giovanni Coco, Z. Zhou, B. van Maanen, M. Olabarrieta, R. Tinoco, I. Townend. Morphodynamics of tidal networks: Advances and challenges. Marine Geology Journal. 1 December 2013.
  20. ^Sandwell, D. T.; Smith, W. H. F. (2006-07-07)."Exploring the Ocean Basins with Satellite Altimeter Data".NOAA/NGDC.Retrieved2007-04-21.
  21. ^Charette, Matthew A.; Smith, Walter H. F. (June 2010)."The Volume of Earth's Ocean".Oceanography.23(2): 112–114.doi:10.5670/oceanog.2010.51.hdl:1912/3862.
  22. ^Braathen, Alvar; Brekke, Harald (7 January 2020).Chapter 1 Characterizing the Seabed: a Geoscience Perspective.Brill Nijhoff. pp. 21–35.doi:10.1163/9789004391567_003.ISBN9789004391567.S2CID210979539.Retrieved13 October2021.
  23. ^ab"The Discovery of Hydrothermal Vents".Woods Hole Oceanographic Institution.11 June 2018.Retrieved13 October2021.
  24. ^Wefer, Gerold; Billet, David; Hebbeln, Dierk; Jorgensen, Bo Barker; Schlüter, Michael; Weering, Tjeerd C. E. Van (2013-11-11).Ocean Margin Systems.Springer Science & Business Media.ISBN978-3-662-05127-6.
  25. ^"Ocean Surface Topography".Science Mission Directorate.31 March 2010.Retrieved13 October2021.
  26. ^May, Tiffany (7 October 2020)."Hidden Beneath the Ocean's Surface, Nearly 16 Million Tons of Microplastic".The New York Times.Retrieved30 November2020.
  27. ^"14 million tonnes of microplastics on sea floor: Australian study".phys.org.Retrieved9 November2020.
  28. ^Barrett, Justine;Chase, Zanna;Zhang, Jing; Holl, Mark M. Banaszak; Willis, Kathryn; Williams, Alan; Hardesty, Britta D.; Wilcox, Chris (2020)."Microplastic Pollution in Deep-Sea Sediments From the Great Australian Bight".Frontiers in Marine Science.7.doi:10.3389/fmars.2020.576170.ISSN2296-7745.S2CID222125532.Available underCC BY 4.0.
  29. ^Muñoz-Royo, Carlos; Peacock, Thomas; Alford, Matthew H.; Smith, Jerome A.; Le Boyer, Arnaud; Kulkarni, Chinmay S.; Lermusiaux, Pierre F. J.; Haley, Patrick J.; Mirabito, Chris; Wang, Dayang; Adams, E. Eric; Ouillon, Raphael; Breugem, Alexander; Decrop, Boudewijn; Lanckriet, Thijs (2021-07-27)."Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds".Communications Earth & Environment.2(1): 148.Bibcode:2021ComEE...2..148M.doi:10.1038/s43247-021-00213-8.hdl:1721.1/138864.2.ISSN2662-4435.
  30. ^Mineral commodity summaries 2024(Report). U.S. Geological Survey. 2024. p. 63.doi:10.3133/mcs2024.
  31. ^"Exploration Contracts".International Seabed Authority.17 March 2022.Retrieved31 July2024.
  32. ^"Deep-sea mining's future still murky as negotiations end on mixed note".Mongabay.2 April 2024.
  33. ^Kuo, Lily (October 19, 2023)."China is set to dominate the deep sea and its wealth of rare metals".Washington Post.Retrieved2024-02-14.
  34. ^"Greenpeace responds to Norway's proposal to licence first Arctic areas for deep sea mining".26 June 2024.
  35. ^"Cook Islands Seabed Minerals Authority - Map".Archivedfrom the original on 2022-06-30.Retrieved2022-07-06.
  36. ^"Campaign Reports | Deep Sea Mining: Out Of Our Depth".2011-11-19.Archivedfrom the original on 2019-12-13.Retrieved2021-09-06.
  37. ^abSPC (2013).Deep Sea Minerals: Deep Sea Minerals and the Green EconomyArchived2021-11-04 at theWayback Machine.Baker, E., and Beaudoin, Y. (Eds.) Vol. 2, Secretariat of the Pacific Community
  38. ^"Breaking Free From Mining"(PDF).Archived fromthe original(PDF)on 2021-12-23.
  39. ^Kim, Rakhyun E. (August 2017). "Should deep seabed mining be allowed?".Marine Policy.82:134–137.Bibcode:2017MarPo..82..134K.doi:10.1016/j.marpol.2017.05.010.hdl:1874/358248.
  40. ^Costa, Corrado; Fanelli, Emanuela; Marini, Simone; Danovaro, Roberto; Aguzzi, Jacopo (2020)."Global Deep-Sea Biodiversity Research Trends Highlighted by Science Mapping Approach".Frontiers in Marine Science.7:384.doi:10.3389/fmars.2020.00384.hdl:10261/216646.
  41. ^Rosenbaum, Dr. Helen (November 2011)."Out of Our Depth: Mining the Ocean Floor in Papua New Guinea".Deep Sea Mining Campaign.MiningWatch Canada, CELCoR, Packard Foundation.Archivedfrom the original on 13 December 2019.Retrieved2 May2020.
  42. ^Halfar, Jochen; Fujita, Rodney M. (18 May 2007). "Danger of Deep-Sea Mining".Science.316(5827): 987.doi:10.1126/science.1138289.PMID17510349.S2CID128645876.
  43. ^"Collapse of PNG deep-sea mining venture sparks calls for moratorium".the Guardian.2019-09-15.Archivedfrom the original on 2021-04-11.Retrieved2021-04-02.
  44. ^"David Attenborough calls for ban on 'devastating' deep sea mining".the Guardian.2020-03-12.Archivedfrom the original on 2021-09-06.Retrieved2021-09-06.
  45. ^"Google, BMW, Volvo, and Samsung SDI sign up to WWF call for temporary ban on deep-sea mining".Reuters.2021-03-31.Archivedfrom the original on 2021-09-06.Retrieved2021-09-06.
  46. ^"SPC-EU Deep Sea Minerals Project - Home".dsm.gsd.spc.int.Archivedfrom the original on 2021-09-06.Retrieved2021-09-06.
  47. ^"The Environmental Protection Authority (EPA) has refused an application by Chatham Rock Phosphate Limited (CRP)".Deepwater group.2015.Archivedfrom the original on 2016-01-24.Retrieved6 September2021.
  48. ^John J. Gurney, Alfred A. Levinson, and H. Stuart Smith (1991) Marine mining of diamonds off the West Coast of Southern Africa,Gems & Gemology,p. 206
  49. ^"Seabed Mining".The Ocean Foundation.2010-08-07.Archivedfrom the original on 2021-09-08.Retrieved2021-09-06.
  50. ^Safeguarding the Underwater Cultural HeritageUNESCO.Retrieved 12 September 2012.

Further reading

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[edit]
Look upseabedin Wiktionary, the free dictionary.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Seabed&oldid=1242238417"