The Southern Ocean

Home , Esperanza Base, Villa Las Estrellas

Geography/World Oceans/Southern Ocean

THE SOUTHERN OCEAN

The Southern Ocean is located in the Southern Hemisphere. It is the fourth largest of the five world oceans. It has an area of 20,327 million square kilometers (7,848.3 million square mile). The area of the Southern Ocean is slightly more than two times the area of the United States.

The International Hydrographic Organization defined the Southern Ocean as the water south of 60 degrees latitude in the year 2000. Some see the waters of the Southern Ocean as the southern tips of the Atlantic, Pacific, and Indian Oceans. Others debate its exact boundaries. Maps from Great Britain define the Southern Ocean as south of 55 degrees latitude. Australian maps label all water between Antarctica and the southern coast of Australia the Southern Ocean.

The Southern Ocean has depths between 4,000 and 5,000 meters. It is deepest in the South Sandwich Trench. The deepest part of the Trench is 7,236 meters. The Southern Ocean is unique among the world's oceans because its northern border does not touch a landmass.

The Southern Ocean is divided from the other oceans by the Atlantic Convergence. It is an ocean zone with a unique ecology. In the Atlantic Convergence, the cold, northward-flowing waters of the Antarctic meet the warm waters of the Atlantic, Pacific, and Indian Oceans.

The Southern Ocean includes the Amundsen Sea, Bellingshausen Sea, Ross Sea, part of the Drake Passage, Weddell Sea, and part of the Scotia

Name______Date______

Sea. Ports in the Southern Ocean are Rothera Station, Palmer Station, Villa Las Estrellas, Esperanza Base, and Mawson Station. Its southernmost port is McMurdo Station.

The Southern Ocean is known for extreme winds. Its winds are the strongest winds found anywhere on Earth. The strong winds are caused by the large temperature difference between the Antarctic ice pack and the ocean. Sailors call the 40th, 50th, and 60th parallels the 'Roaring 40s,' 'Furious 50s,' and 'Shrieking 60s' because the intense winds.

The high winds can cause massive waves. Cold temperatures can make a dangerous condition known as 'ship ice.’ In winter, the Southern Ocean is frozen and ships cannot travel there. It has icebergs year round.

Squid, whales, seals, krill, and many kinds of fish live in the Southern Ocean. It is also home to 17 species of penguins. Some believe large oil and gas fields may be in the Southern Ocean. Its resources are deposits of sand and gravel, and fresh water in the form of icebergs.

The Southern Ocean is endangered by damage to the Ozone layer. The Ozone protects earth from UV rays. Phytoplankton are the base of the ocean food chain. Increased UV rays have reduced the phytoplankton population in the Southern Ocean. Scientists say that UV rays are damaging the DNA of some fish. Illegal fishing has led to over-fishing in the Southern Ocean. Long-line fishing has caused the death of many seabirds.

Geography/World Oceans/Southern Ocean

Name______Date______

Choose the best answer for the questions below.

1. The Southern Ocean is the _____ largest of the world oceans. a. third b. fourth c. second d. fifth

2. What is the southernmost port of the Southern Ocean? a. Mawson Station b. Esperanza Base c. Palmer Station d. McMurdo Station

3. Southern Ocean resources are deposits of sand and gravel and a. calcium from ground sea shells b. pockets of mercury c. freshwater in the icebergs d. anthracite coal

4. What makes the Southern Ocean difficult for ships? a. sharks and giant squids b. very strong winds and massive waves c. ship ice and icebergs d. both b and c

5. Australian maps define the Southern Ocean as a. the water south and east of Tasmania to Antarctica b. the water south of the Australian coastline to Antarctica c. the water south of the 60th parallel d. the water south of New Zealand to Antarctica

6. The Southern Ocean is home to 17 species of a. penguins b. krill c. squid d. whales

Geography/World Oceans/Southern Ocean

Name______Date______

Write complete sentences to answer each question.

1. If you were a scientist would you want the area around Antarctica to be recognized as a separate ocean? What reasons would you have? ______

2. What do you think the word convergence in the ocean area called the Atlantic Convergence? ______

3. What do you think will happen if the phytoplankton in the Southern Ocean is reduced by UV rays? ______

4. What can you do to help prevent more UV damage to the wildlife of the Southern Ocean? ______

Geography/World Oceans/Southern Ocean

Name______Date______

Answers to THE SOUTHERN OCEAN

Multiple Choice

1. b 2. d 3. c 4. d 5. b 6. a

Short Answer (suggestions for discussion and answers )

1. Students may understand that there is evidence showing the waters of the Southern Ocean are different from the other oceans because of the Antarctic Circumpolar Current. Its waters more closely resemble the waters south of South America than the waters of the Atlantic, Pacific, and Indian Oceans.

2. Students may infer that converge means that two or more things come together.

3. Phytoplankton form the base of the ocean food chain. When one link in the chain suffers, all links eventually suffer, including humans at the top.

4. Students may try traditional means of reducing their carbon footprint such as recycling, and non-aerosol sprays, but can also write to national and world political leaders asking for regulations in business & resource consumption that lead to mass polluting, ozone depletion, and climate change.