Antarctica ,Earth‘s southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.9 km (1.2 mi).
Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over 200 mm (8 in) along the coast and far less inland. About 70% of the world’s freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost 60 metres (200 ft). Antarctica holds the record for the lowest measured temperature on Earth, −89.2 °C (−128.6 °F). The coastal regions can reach temperatures over 10 °C (50 °F) in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation occurs, it is mostly in the form of lichen or moss.
The chips and chunks of frozen water, suspended on the surface, sparkle like Swarovski crystals when the sun briefly breaks through cloud that hides the summits of the black coastal mountains.
“These glacier bays with sikkusak are the loudest marine environments on Earth,’’ Sevestre says.
The French scientist is taking a break from her work at Scotland’s University of St Andrews to temporarily join the MV Sea Spirit’s expedition crew.
“Listen to the air bubbles popping. That’s air being released that was last in the atmosphere hundreds or thousands of years ago, and it’s loud like rain hitting the water as the icebergs erode around the waterline.
While we see armies of penguins – battalions of chinstraps, gentoos and adelies as well as a lonely emperor and two resettled macaronis – it is ice that’s the highlight of this 11-day voyage to the bays, beaches and islands of the South Shetland Islands and Antarctic Peninsula.
We see our first blocks on day four of Chimu Adventures Classic Antarctica expedition, icebergs the size of apartment blocks pass as the Sea Spirit navigates between Greenwich and Livingston islands in the South Shetlands, and leave the last nuggets behind five days later after sailing the Peninsula from Orne Harbour to Brown Bluff.
Early in the journey I wonder if I will become blasé about ice but I spend hours admiring the magnificent frozen monuments and rise early to watch Neko Harbour glaciers calving before staying on deck until darkness finally settles on Antarctic Sound to spy the tabular bergs born in the Weddell Sea silhouetted against the fiery red sky.
And I will ensure there’s always a box of Rice Bubbles in the pantry so a bowl of cereal can take me back to an afternoon listening to that icy symphony in Cierva Cove.
nvertebrate life of Antarctica includes species of microscopic mites such as Alaskozetes antarcticus, lice, nematodes, tardigrades, rotifers, krill and springtails. The few terrestrial vertebrates are limited to the sub-Antarctic islands.[112] The flightless midge Belgica antarctica, the largest purely terrestrial animal in Antarctica, reaches 6 mm (1⁄4 in) in size.[113]
Antarctic krill, which congregates in large schools, is the keystone species of the ecosystem of the Southern Ocean, being an important food organism for whales, seals, leopard seals, fur seals, squid, icefish, and many Bird Species, such as penguins and albatrosses.[114] Some species of marine animals exist and rely, directly or indirectly, on phytoplankton. Antarctic sea life includes penguins, blue whales, orcas, colossal squids and fur seals.[115] The Antarctic fur seal was very heavily hunted in the 18th and 19th centuries for its pelt by seal hunters from the United States and the United Kingdom.[116] Leopard seals are apex predators in the Antarctic ecosystem and migrate across the Southern Ocean in search of food.[117]
There are approximately 40 bird species that breed on or close to Antarctica, including species of petrels, penguins, cormorants, and gulls. Various other bird species visit the ocean around Antarctica, including some that normally reside in the Arctic.[118] The emperor penguin is the only penguin that breeds during the winter in Antarctica; it and the Adélie penguin breed farther south than any other penguin.[115]
A Census of Marine Life by some 500 researchers during the International Polar Year was released in 2010. The research found that more than 235 marine organisms live in both polar regions, having bridged the gap of 12,000 km (7,456 mi). Large animals such as some cetaceans and birds make the round trip annually. Smaller forms of life, such as sea cucumbers and free-swimming snails also found in both polar oceans. Factors that may aid in their distribution include temperature differences between the deep ocean at the poles and the equator of no more than 5 °C (9 °F) and the major current systems or marine conveyor belts which are able to transport eggs and larva.[119]
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