After visiting the Magellanic penguins and Rockhopper colonies on Bleaker Island of Falkland Islands, the A&K Le Boreal Antarctica Cruise ship spent the next two days on Scotia Sea of the South Atlantic Ocean heading toward South Georgia and the South Sandwich Islands. On the way, we passed by a famous landmark—Shag Rocks—the only sizeable outcrop on the north Scotia Ridge located northwest of South Georgia.
The Shag Rocks (Spanish: Islas Aurora) are six small islands in the westernmost extreme of South Georgia, 240 km (150 mi) west of the main island of South Georgia and 1,000 km (620 mi) off the Falkland Islands. The Shag Rocks are mainly a habitat for sea birds, such as shags, prions, and albatrosses. Because those little islands are positioned approximately along the Antarctic Convergence, sightings of other magnificent marine life such as whales are also very common. At the Antarctic Convergence, the warmer waters from the Equator are mixed with the colder waters from the Antarctica, creating turbulent flows that disturb the nutrient-rich ocean floors and push the nutrients (krills, etc) upward to the ocean surface. This allows the whales and seabirds to feed on krills on ocean surface and explains the prevalent sightings of whales in this area. We saw humpback whales and fin whales on this trip by the Shag Rocks. Other wildlife are imperial shags, prion, and wandering albatross.
Itinerary – At Scotia Sea: En Route to South Georgia
- The Seals of the Antarctic
- Evolution of the Falklands, South Georgia, and Antarctica: From Jurassic Park to Ice Age III
- Photographing Antarctica
- Birds in Tuxedos
- IAATO Guidelines
- The Island of South Georgia: The Jewel in the Crown
No matter from where you sail to see the magnificence of Antarctica, at some point on your voyage you’ll pass over the Antarctic Convergence, or the Polar Front as it is sometimes named. The ocean south of the Convergence differs greatly from northern waters in salinity and temperature. Colder, less saline Antarctic surface water flows northward from the continent meeting warmer, saltier water flowing southward from the South Pacific, South Atlantic and Indian Oceans. Where these two water masses meet and mix, a denser layer is created and sinks, flowing northward. The Convergence is considered the biological boundary of Antarctica.
The exact location of the Convergence varies slightly throughout the year and from year to year. Despite what you may read, there is very little sign that you are crossing the Convergence. The sea does not get rougher and there is usually no change in its appearance. The primary indicator is a sudden dip in the water temperature, a change that the ship’s instruments will detect. The sea temperature may drop up to 5oC / 9oF in just two hours, over a distance of about 32 kilometers / 20 miles. If you spend time out on deck you’ll notice the air is appreciably chillier.
An important feature of the Southern Ocean is the Antarctic Circumpolar Current. This is the world’s biggest ocean current flowing eastwards at the rate of 153 million cubic meters / 5,403,143,930 cubic feet per second, about 1000x the flow of the Amazon River.
Meals – At Scotia Sea: En Route to South Georgia
Back to Antarctic Expedition to read other destinations of the trip.