 |
 |
|
||
You are here: Cruise News » Drake Passage 2011 » Background
Bathymetry of Drake Passage.
Currents and fronts in the Southern Ocean. The region shaded darker blue is the path of the ACC.
Every year, in southern spring, the British Antarctic Survey's ship the RSS James Clark Ross leaves Stanley in the Falklands to take scientists and supplies to the Rothera research station on Adelaide Island in the Antarctic Peninsula.
And every year oceanographers from the National Oceanography Centre join the ship for the voyage across Drake Passage.
Why?
Well, it helps us learn more about Earth's climate by understanding the mightiest of all ocean currents - the ACC.
ACC is short for the Antarctic Circumpolar Current - so called because it circles the continent of Antarctica. It is driven by strong westerly winds between 40 and 60 degrees South, and links all the main oceans - the Pacific, Atlantic and Indian Oceans.
Drake Passage is a good place to study the ACC. Here the flow is squeezed between Antarctica and South America, and shrinks from almost 2000 km wide to about 800 km.
Nearly 140 Sverdrup of water flows through the gap between Cape Horn and the Antarctic Peninsula. That's 140 times the flow of all the world's rivers.
The ACC reaches from the surface to a depth of over 4km, so it links the surface and deep ocean. It plays an important part in the global ocean conveyor, which transports heat from the tropics to high latitudes.
Life in the Antarctic
The Drake Passage cruises are not designed to study Antarctic ecology, but the scientists and crew of the JCR will see many Antarctic animals. It is spring in the Southern Hemisphere, and seals, whales, penguins and other birds, are busy taking advantage of short summer, to rear their young, and eat as much as they can before the next winter.
Tiny zooplankton and krill feed on blooms of phytoplankton and ice algae. Larger animals seek out the blooms to feed on zooplankton and krill. Even larger animals come to feed on the animals that feed on the animals that feed ...
... and so on, up to the top predators, who have no predators of their own - at least as adults. The images below link to information about the creatures that live in this amazing world.
| ||||||||
| ||||||||
Phytoplankton
Ice algae 
Zooplankton
Krill 
Antarctic silverfish
Squid
Adelie penguin
Cape pigeon
Blue whale
Weddell seal
|
Last update: 06 December 2011 |
Contact: o4s@noc.soton.ac.uk |