View source for Labrador Sea

{{Short description|Arm of the North Atlantic Ocean}}
{{Use dmy dates|date=January 2025}}
{{Use Canadian English|date=January 2025}}
{{Infobox sea
| name               = Labrador Sea
| image              = Labrador-sea-paamiut.jpg
| caption            = Past sunset at Labrador Sea, off the coast of [[Paamiut]] (Frederikshåb), [[Greenland]]
| image_bathymetry   = Labrador sea map.png
| caption_bathymetry = 
| location           = 
| pushpin_map        = Canada
| coords             = {{coord|61|N|56|W|type:waterbody_scale:10000000|name=Labrador Sea|display=inline,title}}
| type               = [[Sea]]
| inflow             = 
| outflow            = 
| catchment          = 
| basin_countries    = [[Canada]] and [[Greenland]]
| length             = c. {{cvt|1000|km|0}}
| width              = c. {{cvt|900|km|0}}
| area               = {{cvt|841000|km2|-2}}
| depth              = {{cvt|1898|m|0}}
| max-depth          = {{cvt|4316|m|0}}
| reference          = <ref name=bse>{{cite web|url=http://dic.academic.ru/dic.nsf/enc_geo/153/%D0%9B%D0%90%D0%91%D0%A0%D0%90%D0%94%D0%9E%D0%A0#%D0%9B%D0%B0%D0%B1%D1%80%D0%B0%D0%B4%D0%BE%CC%81%D1%800|language=ru|title=Labrador|publisher=[[Great Soviet Encyclopedia]]}}</ref><ref name=r1>{{cite journal|author1=Wilson, R. C. L|author2=London, Geological Society of|doi=10.1144/GSL.SP.2001.187.01.05|title=Non-volcanic rifting of continental margins: a comparison of evidence from land and sea|isbn=978-1-86239-091-1|year=2001|page=77|volume=187|journal=Geological Society, London, Special Publications|issue=1 |url=https://books.google.com/books?id=-bsvkxVBTasC&pg=PA77|bibcode=2001GSLSP.187...77C|s2cid=140632779|url-access=subscription}}</ref>
| other_name         = Labradorhavet
}}
The '''Labrador Sea''' ({{langx|fr|mer du Labrador}}; {{langx|da|Labradorhavet}}) is an arm of the [[North Atlantic Ocean]] between the [[Labrador Peninsula]] and [[Greenland]]. The sea is flanked by [[continental shelf|continental shelves]] to the southwest, northwest, and northeast. It connects to the north with [[Baffin Bay]] through the [[Davis Strait]].<ref name=brit>{{cite web|url=http://www.britannica.com/eb/article-9046724/Labrador-Sea|title=Labrador Sea|author=Encyclopædia Britannica|author-link=Encyclopædia Britannica|access-date=2008-02-03}}</ref> It is a [[marginal sea]] of the Atlantic.<ref name="Calow1999">{{cite book|first=Peter|last=Calow|title=Blackwell's concise encyclopedia of environmental management|url=https://books.google.com/books?id=0E0LP-pPCWwC&pg=PA7|access-date=29 November 2010|date=12 July 1999|publisher=[[Wiley-Blackwell]]|isbn=978-0-632-04951-6|page=7}}</ref><ref>{{cite journal|author=Spall, Michael A. |title=Boundary Currents and Watermass Transformation in Marginal Seas |doi=10.1175/1520-0485(2004)034<1197:BCAWTI>2.0.CO;2 |journal=J. Phys. Oceanogr. |volume=34 |pages=1197–1213|year=2004|issue=5|bibcode=2004JPO....34.1197S |s2cid=128436726 }}</ref>

The sea formed upon separation of the [[North American Plate]] and [[Greenland Plate]] that started about 60 million years ago and stopped about 40 million years ago. It contains one of the world's largest [[turbidity current]] channel systems, the [[Northwest Atlantic Mid-Ocean Channel]] (NAMOC), that runs for thousands of kilometres along the sea bottom toward the Atlantic Ocean.

The Labrador Sea is a major source of the [[North Atlantic Deep Water]], a cold water mass that flows at great depth along the western edge of the North Atlantic.
[[File:Labrador Sea in its region.svg|thumb|right|Map showing the Labrador Sea according to the [[International Hydrographic Organization|IHO]] definition]]

==History==
The Labrador Sea formed upon separation of the [[North American Plate]] and [[Greenland Plate]] that started about 60 million years ago ([[Paleocene]]) and stopped about 40 million years ago.<ref name=r1/> A [[sedimentary basin]], which is now buried under the continental shelves, formed during the [[Cretaceous]].<ref name=r1/> Onset of magmatic [[sea-floor spreading]] was accompanied by volcanic eruptions of [[picrite]]s and [[basalt]]s in the [[Paleocene]] at the Davis Strait and Baffin Bay.<ref name=r1/>

Between about 500 BC and 1300 AD, the southern coast of the sea contained [[Dorset culture|Dorset]], [[Beothuk]], and [[Inuit]] settlements; Dorset tribes were later replaced by [[Thule people]].<ref>''Grønlands forhistorie'', ed. Hans Christian Gulløv, Gyldendal 2005, {{ISBN|87-02-01724-5}}</ref>

==Extent==
{{GeoGroupTemplate}}
The [[International Hydrographic Organization]] defines the limits of the Labrador Sea as follows:<ref>{{cite web|url=https://iho.int/uploads/user/pubs/standards/s-23/S-23_Ed3_1953_EN.pdf|title=Limits of Oceans and Seas, 3rd edition|year=1953|publisher=International Hydrographic Organization|access-date=28 December 2020|archive-url=https://web.archive.org/web/20111008191433/http://www.iho.int/iho_pubs/standard/S-23/S-23_Ed3_1953_EN.pdf|archive-date=8 October 2011}}</ref>

<blockquote>
On the North: the South limit of [[Davis Strait]] [The parallel of [[60th parallel north|60° North]] between [[Greenland]] and [[Labrador]]].

On the East: a line from Cape St. Francis {{coord|47|45|N|52|27|W|type:waterbody_scale:10000000_region:CA-NL|name=Cape St. Francis}} ([[Newfoundland and Labrador|Newfoundland]]) to [[Cape Farewell, Greenland|Cape Farewell]] (Greenland).

On the West: the East Coast of Labrador and Newfoundland and the Northeast limit of the [[Gulf of Saint Lawrence|Gulf of St. Lawrence]] – a line running from [[Cape Bauld]] (North point of [[Quirpon Island|Kirpon Island]], {{coord|51|40|N|55|25|W|type:waterbody_scale:10000000_region:CA-NL|name=Cape Bauld}}) to the East extreme of [[Belle Isle (Newfoundland and Labrador)|Belle Isle]] and on to the Northeast Ledge ({{coord|52|02|N|55|15|W|type:waterbody_scale:10000000_region:CA-NL|name=Belle Isle}}). Thence a line joining this ledge with the East extreme of [[Cape St. Charles]] (52°13'N) in Labrador.
</blockquote>
[[Natural Resources Canada]] uses a slightly different definition, putting the northern boundary of the Labrador Sea on a straight line from a headland on [[Killiniq Island]] abutting Lady Job Harbour to Cape Farewell.<ref>{{cite web | url=http://www4.rncan.gc.ca/search-place-names/unique/ABAVX | title=Noms de lieux - Recherche par nom de toponyme }}</ref>

==Oceanography==
[[File:LabradorCurrentus-coastguard.jpg|thumb|right|180px|Major North Atlantic currents]]
The Labrador Sea is about {{convert|3400|m|fathom ft|0|lk=out|abbr=in}} deep and {{convert|1000|km|mi nmi|0|abbr=in|lk=out}} wide where it joins the Atlantic Ocean. It becomes shallower, to less than {{convert|700|m|fathom ft|0|abbr=on}} towards Baffin Bay (see [[:File:IBCAO betamap.jpg|depth map]]) and passes into the {{convert|300|km|mi nmi|abbr=on}} wide [[Davis Strait]].<ref name=r1/> A {{convert|100|–|200|m|fathom ft|abbr=on}} deep [[turbidity current]] channel system, which is about {{convert|2|-|5|km|mi nmi |abbr=on}} wide and {{convert|3,800|km|mi nmi|abbr=on}} long, runs on the bottom of the sea, near its center from the [[Hudson Strait]] into the Atlantic.<ref>{{cite journal |title= Ice-sheet sourced juxtaposed turbidite systems in Labrador Sea |url= http://journals.hil.unb.ca/index.php/GC/article/view/3928 |journal= Geoscience Canada|volume=24|issue=1|page=3|author8=Heisee, R and Klaucke I|date= 3 March 1997 }}</ref><ref>{{cite journal|last1=Reinhard Hesse And Allan Rakofsky |title=Deep-Sea Channel/Submarine-Yazoo System of the Labrador Sea: A New Deep-Water Facies Model (1)|journal=AAPG Bulletin|volume=76|year=1992|doi=10.1306/BDFF88A8-1718-11D7-8645000102C1865D}}</ref> It is called the [[Northwest Atlantic Mid-Ocean Channel]] (NAMOC) and is one of the world's longest drainage systems of Pleistocene age.<ref name=r2>{{cite book|url=https://books.google.com/books?id=LuMgcgupaJcC&pg=PA286|page=286|title=Glaciated continental margins: an atlas of acoustic images|editor= Thomas A. Davies|author=Hesse, R., Klauck, I., Khodabakhsh, S. & Ryan, W. B. F. |year=1997|work=Glacimarine drainage systems in the deep-sea: the NAMOC system of the Labrador Sea and its sibling|publisher=Springer|isbn=0-412-79340-7}}</ref> It appears as a submarine river bed with numerous tributaries and is maintained by high-density turbidity currents flowing within the [[levee]]s.<ref>{{cite book|url=https://books.google.com/books?id=-N3nidyNoJUC&pg=PA234|page=234|title=Sedimentary basins: evolution, facies, and sediment budget|first=Gerhard|last=Einsele|publisher=Springer|year=2000|isbn=3-540-66193-X}}</ref>

The water temperature varies between {{Convert|-1|C}} in winter and {{Convert|5|-|6|C|F}} in summer. The salinity is relatively low, at 31–34.9 parts per thousand. Two-thirds of the sea is covered in ice in winter. Tides are [[Earth tide|semi-diurnal]] (i.e. occur twice a day), reaching {{Convert|4|m|fathom ft|abbr=on}}.<ref name=bse/>

There is an anticlockwise water circulation in the sea. It is initiated by the [[East Greenland Current]] and continued by the [[West Greenland Current]], which brings warmer, more saline waters northwards, along the Greenland coasts up to the Baffin Bay. Then, the [[Baffin Island Current]] and [[Labrador Current]] transport cold and less saline water southward along the Canadian coast. These currents carry numerous icebergs and therefore hinder navigation and exploration of the gas fields beneath the sea bed.<ref name=brit/><ref name=can>{{cite encyclopedia|url=https://www.thecanadianencyclopedia.ca/en/article/labrador-sea|title=Labrador Sea|author=Kenneth F. Drinkwater, R. Allyn Clarke|encyclopedia=The Canadian Encyclopedia|access-date=2008-02-03|archive-date=2018-08-02|archive-url=https://web.archive.org/web/20180802162457/https://www.thecanadianencyclopedia.com/en/article/labrador-sea/|url-status=live}}</ref> The speed of the Labrador current is typically {{Convert|0.3|-|0.5|m/s|abbr=on}}, but can reach {{Convert|1|m/s|abbr=on}} in some areas,<ref>{{cite journal|author1=Petrie, B. |author2=A. Isenor |year=1985 |title=The near-surface circulation and exchange in the Newfoundland Grand Banks region |journal=Atmosphere-Ocean |volume=23 |issue=3 |pages=209–227 |doi=10.1080/07055900.1985.9649225 |doi-access=free |bibcode=1985AtO....23..209P }}</ref> whereas the Baffin Current is somewhat slower at about {{Convert|0.2|m/s|abbr=on}}.<ref>{{cite web|url=http://www.britannica.com/EBchecked/topic/48703/Baffin-Island-Current|title=Baffin Current|author=Encyclopædia Britannica|author-link=Encyclopædia Britannica|access-date=2010-02-03}}</ref> The Labrador Current maintains the water temperature at {{Convert|0|C}} and salinity between 30 and 34 parts per thousand.<ref>{{cite web|url=http://www.britannica.com/EBchecked/topic/327001/Labrador-Current|title=Labrador Current|author=Encyclopædia Britannica|author-link=Encyclopædia Britannica|access-date=2010-02-03}}</ref>

The sea provides a significant part of the [[North Atlantic Deep Water]] (NADW) — a cold water mass that flows at great depth along the western edge of the North Atlantic, spreading out to form the largest identifiable water mass in the [[World Ocean]].<ref>{{cite book|url=https://books.google.com/books?id=JMI6AAAAIAAJ&pg=PA179|page=179|title=Earth systems: processes and issues|author=Wallace Gary Ernst|publisher=[[Cambridge University Press]]|year=2000|isbn=0-521-47895-2}}</ref> The NADW consists of three parts of different origin and salinity, and the top one, the Labrador Sea Water (LSW), is formed in the Labrador Sea. This part occurs at a medium depth and has a relatively low salinity (34.84–34.89 parts per thousand), low temperature ({{Convert|3.3|-|3.4|C|F|1}}) and high oxygen content compared to the layers above and below it. LSW also has a relatively low vorticity, i.e. the tendency to form vortices, than any other water in North Atlantic that reflects its high homogeneity. It has a [[potential density]] of 27.76–27.78&nbsp;mg/cm<sup>3</sup> relatively to the surface layers, meaning it is denser, and thus sinks under the surface and remains homogeneous and unaffected by the surface fluctuations.<ref>{{Cite FTP |last1=Talley|first1=L.D.|last2=McCartney|first2=M.S.|title=Distribution and Circulation of Labrador Sea Water|doi=10.1175/1520-0485(1982)012<1189:DACOLS>2.0.CO;2|issn=1520-0485|year=1982|page=1189|volume=12|url=ftp://gyre.ucsd.edu/nonpub/talley/papers/1980s/talley_mccartney_jpo_1982.pdf|issue=11|server=Journal of Physical Oceanography|url-status=dead|bibcode=1982JPO....12.1189T}}</ref>

==Fauna==
The northern and western parts of the Labrador Sea are covered in ice between December and June. This [[drift ice]] serves as a breeding ground for several types of [[Pinniped|pinnipeds]] (including [[Walrus|Atlantic walrus]] and [[Bearded seal|bearded]], [[Grey seal|grey]], [[Harbor seal|harbor]], [[Harp seal|harp]], [[Hooded seal|hooded]] and [[Ringed seal|ringed seals]]). Several [[Cetacea|cetacean]] species feed in these abundant waters in early spring, including [[Blue whale|blue]], [[Fin whale|fin]], [[Humpback whale|humpback]], [[Long-finned pilot whale|long-finned pilot]], [[Minke whale|minke]], the critically endangered [[North Atlantic right whale|North Atlantic right]], [[Sei whale|sei]] and [[Sperm whale|sperm whales]].<ref name=":0">{{Cite web |date=25 October 2024 |title=Observations • iNaturalist |url=https://www.inaturalist.org/observations?nelat=60.37774399999999&nelng=-52.61936619999999&subview=map&swlat=46.6109839&swlng=-67.8216853&taxon_id=152871&view=species }}</ref> The sea contains one of the two primary populations of sei whales, the other being the [[Scotian Shelf]].<ref>{{cite book |author1=Anthony Bertram Dickinson |url=https://books.google.com/books?id=uDMG4kPdcn4C&pg=PA16 |title=Twentieth-century shore-station whaling in Newfoundland and Labrador |author2=Chesley W. Sanger |publisher=McGill-Queen's Press – MQUP |year=2005 |isbn=0-7735-2881-4 |pages=16–17}}</ref> Pods of [[Beluga whales|beluga]] (white) whales are more common further to the north, west and south (notably in [[Baffin Bay]], where their population reaches around 20,000 animals), and further afield in [[Hudson Bay]] and the [[Gulf of St. Lawrence|Gulf of Saint Lawrence]]. While somewhat rarer in the Labrador Sea—especially since the 1950s—<ref>[http://dsp-psd.pwgsc.gc.ca/Collection/CW69-14-170-2004E.pdf COSEWIC Assessment and Update Status Report on the Beluga Whale]. Dsp-psd.pwgsc.gc.ca (2012-07-31). Retrieved on 2013-03-20.</ref> some sightings still take place.<ref>{{Cite web |date=24 October 2024 |title=Observations • iNaturalist |url=https://inaturalist.org/observations?subview=map&taxon_id=41461 }}</ref> Additionally, pods of [[orca]] are drawn to the sea by the large shoals of fish, as well as the many marine mammal species they may hunt (including other cetaceans and pinnipeds), such as [[harbour porpoise]] and [[Atlantic white-sided dolphin|Atlantic white-sided]], [[Common dolphin|common]], [[Striped dolphin|striped]] and [[White-beaked dolphin|white-beaked dolphins]].<ref name=":0" />

The sea is also a feeding-ground for [[Atlantic salmon]]. [[shrimp fishery|Shrimp fisheries]] began in 1978, intensifying by 2000, in addition to [[cod]] fishing. However, by the [[1990s]], the [[Cod fishing in Newfoundland|cod fishing]] had already depleted the fishes' population near the Labrador and West Greenland banks, and was therefore halted in 1992.<ref name="can" /> Other fishery targets include [[haddock]], [[Atlantic herring]], [[lobster]], several species of [[flatfish]], and [[pelagic fish]], such as [[sand lance]] and [[capelin]]. They are most abundant in the southern parts of the sea.<ref>{{cite book|pages=6–7|url=https://books.google.com/books?id=aTcrAAAAYAAJ&pg=PA6|title=Maritime services to support polar resource development|author=National Research Council (U.S.)|year=1981}}</ref>

[[File:Labrador Tea flower.jpg|thumb|right|180px|Close up of a [[Labrador tea]] flower]]
The [[Labrador duck]] was a common bird on the Canadian coast until the 19th century, but is now extinct.<ref>{{cite journal|author=Ducher, William |year=1894|title=The Labrador Duck – another specimen, with additional data respecting extant specimens|journal=Auk|volume=11|issue=1|pages=4–12|url=http://sora.unm.edu/sites/default/files/journals/auk/v011n01/p0004-p0012.pdf|doi=10.2307/4067622|jstor=4067622}}</ref> Other coastal animals include the [[Labrador wolf]] (''Canis lupus labradorius''),<ref>{{cite journal|doi=10.2307/1374306|title=The Wolves of North America|jstor=1374306|author=E. A. Goldman|journal=Journal of Mammalogy|volume=18|issue=1 |year=1937|pages=37–45}}</ref><ref>{{cite journal|url=http://pubs.aina.ucalgary.ca/arctic/Arctic39-2-145.pdf|journal=Arctic|volume=39|issue=2|year=1986|pages=145–149|title=Characteristics of the Wolf (Canis lupus lubrudorius Goldman) in Northern Quebec and Labrador|author1=G.R. Parker|author2=S. Luttich|doi=10.14430/arctic2062|access-date=2010-09-02|archive-date=2020-07-01|archive-url=https://web.archive.org/web/20200701110614/http://pubs.aina.ucalgary.ca/arctic/Arctic39-2-145.pdf|url-status=dead}}</ref> [[Migratory woodland caribou|woodland caribou]] (''Rangifer tarandus caribou''), [[moose]] (''Alces alces''), [[American black bear|black bear]] (''Ursus americanus''), [[Canada lynx]] (''Lynx canadensis''), [[red fox]] (''Vulpes vulpes''), [[Arctic fox]] (''Alopex lagopus''), [[wolverine]] (''G. gulo''), [[American mink]] (''Neogale vison''), [[North American river otter]] (''Lontra canadensis''), [[snowshoe hare]] (''Lepus americanus''), [[grouse]] (''Dendragapus'' spp.), [[osprey]] (''Pandion haliaetus''), [[Common raven|raven]] (''Corvus corax''), [[Duck|ducks]], [[Goose|geese]], [[Swan|swans]], [[partridge]] and [[Common pheasant|pheasant]].<ref>{{cite book|pages=9–11|url=https://books.google.com/books?id=bwo4J063Q50C&pg=PA9|title=The Moravians in Labrador|year=2006|isbn=1-4068-0512-2|author1=Anonymous| publisher=Echo Library }}</ref><ref name=f>{{WWF ecoregion|name=Eastern Canadian Shield taiga|id=na0606}}</ref> Occasionally, coastal [[polar bear]] (''Ursus maritimus'') sightings occur along the sea, mainly further north but sometimes as far south as [[Conception Bay (Canada)|Conception Bay]] and the mouth of the Gulf of Saint Lawrence.<ref>{{Cite web |date=24 October 2024 |title=Observations • iNaturalist |url=https://inaturalist.org/observations?subview=map&taxon_id=41644 }}</ref>

==Flora==
Coastal vegetation includes [[black spruce]] (''Picea mariana''), [[tamarack]], [[white spruce]] (''P. glauca''), [[dwarf birch]] (''Betula'' spp.), [[aspen]], [[willow]] (''Salix'' spp.), ericaceous shrubs (''[[Ericaceae]]''), [[cottongrass]] (''Eriophorum'' spp.), [[sedge]] (''Carex'' spp.), lichens and moss.<ref name=f/> Evergreen bushes of [[Labrador tea]], which is used to make [[herbal tea]]s, are common in the area, both on the Greenland and Canadian coasts.<ref>[http://www.fs.fed.us/global/iitf/pdf/shrubs/Ledum%20groenlandicum.pdf Ledum groenlandicum Oeder – Labrador Tea]. (PDF) . Retrieved on 2013-03-20.</ref>

==References==
{{reflist|30em}}

{{List of seas}}
{{Marginal seas of the Atlantic Ocean}}

{{Authority control}}

[[Category:Labrador Sea| ]]
[[Category:Oceanography]]
[[Category:Seas of Greenland]]
[[Category:Seas of the Atlantic Ocean]]
[[Category:Bodies of water of Newfoundland and Labrador]]
[[Category:Seas of Canada]]
[[Category:Seas of North America]]
[[Category:Geography of North America]]
[[Category:Cenozoic rifts and grabens]]