Dictionary of Meaning
<<Back
Please select a letter:
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
0-9
Click here for Shopping
Southern Ocean
*** Shopping-Tip: Southern Ocean
{{Five oceans}}
The '''Southern Ocean''' is the body of water encircling the continent of
Antarctica according to some geographic and most hydrographic sources. It is the world's fourth largest
ocean and the latest defined, having been accepted by a decision of the
International Hydrographic Organization (IHO) in
2000, though the term has long been traditional among mariners. This change reflects the recent findings in
oceanography of the importance of
ocean currents.
Other sources such as the
National Geographic Society continue to show the
Atlantic Ocean Atlantic,
Pacific Ocean Pacific and
Indian Ocean Indian Oceans as extending to Antarctica. Only 28 of the world's 193 nations responded to the IHO survey in 2000, with just 18 voting for a new name, "Southern Ocean." Only 14 votes were cast for ending the ocean at the imaginary 60 degrees south line of latitude, with the other 14 votes cast for other definitions as far north as 35 degrees south, the equivalent latitude south of the equator as that of the
Mediterranean Sea in the northern hemisphere.
Image:Southern Ocean.png right|Southern Ocean
Geography
The Southern Ocean is oceanographically defined as an ocean connected with the
Antarctic Circumpolar Current, which circulates around Antarctica. It includes
Amundsen Sea,
Bellingshausen Sea, part of the
Drake Passage,
Ross Sea, a small part of the
Scotia Sea, and
Weddell Sea. The total area is 20,327,000 km², and the coastline length is 17,968 km.
The geographic coordinates is {{coor dm|65|00|S|0|00|E|}} nominally, but the Southern Ocean has the unique distinction of being a large circumpolar body of water totally encircling the continent of Antarctica as opposed to the normal definition of an ocean or sea, that of a water body mostly surrounded by land; this ring of water lies between 60 degrees south latitude and the coast of Antarctica, and encompasses 360 degrees of longitude.
This definition is, however, not universal. In
Australia the Southern Ocean is defined in the same manner as the IHO but also includes the entire body of water between Antarctica and the south coasts of Australia and
New Zealand, and is marked as such on maps. In particular, coastal maps of
Tasmania and
South Australia always label the sea areas as ''Southern Ocean'' and never ''Indian Ocean''.
[http://aadc-maps.aad.gov.au/database/mapcat/antarctica/aust_to_ant_jan04.pdf Map showing Australian definition of the Southern Ocean] (
Portable Document Format PDF)
The Southern Ocean was formed oceanographically when Antarctica and
South America moved apart opening the Drake Passage and the Antarctic Circumpolar Current was formed roughly 30 million years ago, which makes the ocean much younger than other oceans.
The major chokepoint is the
Drake Passage. The Polar Front (Antarctic Convergence) is the best natural definition of the northern extent of the Southern Ocean; it is a distinct region at the middle of the Antarctic Circumpolar Current that separates the very cold polar surface waters to the south from the warmer waters to the north; the Front and the Current extend entirely around Antarctica, reaching south of 60 degrees south near New Zealand and near 48 degrees south in the far South Atlantic coinciding with the path of the maximum westerly winds.
Image:Iceedgekils.gif
The
packice zone pulsates over the year.
Climate
Sea temperatures vary from about -2 to 10
Celsius °C (28 to 50
Fahrenheit °F). Cyclonic storms travel eastward around the continent and frequently are intense because of the temperature contrast between ice and open
ocean. The ocean area from about latitude 40 south to the
Antarctic Circle has the strongest average winds found anywhere on
Earth. In winter the ocean freezes outward to 65 degrees south latitude in the Pacific sector and 55 degrees south latitude in the Atlantic sector, lowering surface temperatures well below 0 degrees Celsius; at some coastal points intense persistent drainage winds from the interior keep the shoreline ice-free throughout the winter.
Terrain
The Southern Ocean is deep, 4,000 to 5,000 meters over most of its extent with only limited areas of shallow water. The
Antarctic continental shelf is generally narrow and unusually deep, its edge lying at depths of 400 to 800 meters (the global mean is 133 meters). The Antarctic ice pack fluctuates from an average minimum of 2.6 million square kilometers in March to about 18.8 million square kilometers in September, more than a sevenfold increase in area. The
Antarctic Circumpolar Current (21,000 km in length) moves perpetually eastward; it is the world's largest ocean current, transporting 130 million cubic meters of water per second - 100 times the flow of all the world's rivers.
Elevation extremes
* ''lowest point:'' -7,235 m at the southern end of the
South Sandwich Trench, at 60°00'S, 024°W
* ''highest point:'' sea level 0 m.
Natural resources
* Probable large and possible giant
Petroleum oil and
gas fields on the continental margin
*
Manganese nodules
* Possible
placer deposits
* Sand and gravel
* Fresh water as
icebergs
*
Squid,
whales,
seal (mammal) seals,
krill and various
fish
Natural hazards
Huge icebergs with drafts up to several hundred meters; smaller bergs and iceberg fragments; sea ice (generally 0.5 to 1 meter thick) with sometimes dynamic short-term variations and with large annual and interannual variations; deep continental shelf floored by glacial deposits varying widely over short distances; high winds and large waves much of the year; ship icing, especially May-October; most of the region is remote from sources of search and rescue.
Environment
Current issues
* Increased solar
ultraviolet ultraviolet radiation resulting from the Antarctic
ozone hole, reducing marine primary productivity (
phytoplankton) by as much as 15% and damaging the
DNA of some fish.
* illegal, unreported, and unregulated fishing, especially the landing of an estimated five to six times more
Patagonian toothfish than the regulated fishery, which is likely to affect the sustainability of the stock.
* high incidental mortality of seabirds resulting from long-line fishing for toothfish.
International agreements
The Southern Ocean is subject to all international agreements regarding the world's oceans. In addition, it is subject to these agreements specific to the region:
International Whaling Commission (prohibits commercial whaling south of 40 degrees south [south of 60 degrees south between 50 degrees and 130 degrees west]) NOTE: Japan regularly does not recognize this provision in regards to its whaling permit and whaling for scientific research and occaisonally carries out whale hunts in the region.;
Convention for the Conservation of Antarctic Seals (limits sealing);
Convention on the Conservation of Antarctic Marine Living Resources (regulates fishing)
* ''note:'' many nations prohibit
mineral resource exploration and exploitation south of the fluctuating
Polar Front (
Antarctic Convergence) which is in the middle of the Antarctic Circumpolar Current and serves as the dividing line between the very cold polar surface waters to the south and the warmer waters to the north.
Since the
Antarctic Treaty covers the portion of the globe south of sixty degrees south, claims to Antarctica and all islands in the Southern Ocean are suspended.
Economy overview
Fisheries in 1998-1999 (
1 July to
30 June) landed 119,898 metric tons, of which 85% was krill and 14% Patagonian toothfish. International agreements were adopted in late 1999 to reduce illegal, unreported, and unregulated fishing, which in the 1998-1999 season landed five to six times more Patagonian toothfish than the regulated fishery. In the 1998-1999 Antarctic summer 10,013 tourists, most of them seaborne, visited the Southern Ocean and Antarctica, compared to 9,604 the previous year. Nearly 16,000 tourists are expected during the 1999-2000 season.
Ports and harbors
Esperanza Base,
Mawson Station,
McMurdo Station,
Palmer Station,
Scott Base, and offshore anchorages in Antarctica
* ''note:'' few ports or harbors exist on the southern side of the Southern Ocean; ice conditions limit use of most of them to short periods in midsummer; even then some cannot be entered without icebreaker escort; most Antarctic ports are operated by government research stations and, except in an emergency, are not open to commercial or private vessels; vessels in any port south of 60 degrees south are subject to inspection by
Antarctic Treaty System Antarctic Treaty observers.
Transportation note
The
Drake Passage offers an alternative to transit through the
Panama Canal.
See also
*
Antarctica
*
Antarctic Treaty System
References
{{unreferenced}}
External links
{{Wiktionary}}
{{commons|Antarctic ocean}}
-
The CIA World Factbook's article on the Southern Ocean
-
The Fifth Ocean from Geography.About.com
-
NOAA In-situ Ocean Data Viewer Plot and download ocean observations
Category:Southern Ocean
Category:Oceans
Category:Antarctica
an:Ozián Glazial Antartico
zh-min-nan:Lâm-keÌ?k-iûâ?¿
ca:Oceà Antà rtic
cv:Кăнтăр океан
cs:Jižnà oceán
cy:Cefnfor y De
da:Sydhavet
de:Südlicher Ozean
et:Lõuna-Jäämeri
el:Î?ότιος Ωκεανός
es:Océano Glacial Antártico
fr:Océan austral
gl:Océano Antártico
ko:남극해
hr:Južni ocean
io:Antarktika Oceano
id:Samudra Selatan
is:Suður-�shaf
it:Mari antartici
he:×”×?×•×§×™×™× ×•×¡ הדרומי
ka:ს�მხრეთის �კე�ნე
la:Oceanus Antarcticus
lt:Pietų vandenynas
hu:Déli-óceán
nl:Zuidelijke Oceaan
ja:�極海
no:Sørishavet
nn:Sørishavet
pl:Ocean Południowy
pt:Oceano Antártico
ro:Oceanul Antarctic
ru:Южный океан
simple:Southern Ocean
sk:Južný oceán
sl:Južni ocean
sr:Јужни океан
fi:Eteläinen jäämeri
sv:Antarktiska oceanen
ta:தென�னகப� பெர�ங�கடல�
th:มหาสมุทรใต้
vi:Nam Ä?ại DÆ°Æ¡ng
tr:Güney Okyanusu
zh:å?—æž?æ´‹
The Southern Ocean is the body of water encircling the continent of
Antarctica.
Category:Oceans
fr:Catégorie:Océan Antarctique
ko:분류:남극해
no:Kategori:Sørishavet
ru:КатегориÑ?:Южный океан
*** Shopping-Tip: Southern Ocean
