Southern Ocean, Antarctica, Glaciers, Expedition Cruise, Icebergs, by Kai Müller

The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín in Argentina and originally as Graham Land in the United Kingdom and Palmer Peninsula in the United States, is the northernmost part of the Antarctic mainland. The Antarctic Peninsula is part of the larger West Antarctic Peninsula and juts out 1,300 km (810 miles) from a line between Cape Adams (Weddell Sea) and a point on the mainland south of the Eklund Islands. Beneath the ice sheet that covers it, the Antarctic Peninsula consists of a series of bedrock islands; these are separated by deep channels whose floors lie at depths considerably below current sea level. They are connected by a grounded ice sheet. Tierra del Fuego, the southernmost tip of South America, is about 1,000 km (620 miles) away via the Drake Passage. The Antarctic Peninsula is 522,000 square kilometres (202,000 square miles) and 80% ice-covered. The marine ecosystem around the western continental shelf of the Antarctic Peninsula is undergoing rapid climate change. Over the last 50 years, the warm, wet marine climate of the northern WAP has shifted southwards. This climate change is increasingly displacing the once predominant cold, dry continental climate of Antarctica. This regional warming has caused multi-level responses in the marine ecosystem, such as increased heat transport, decreased sea ice extent and duration, local declines in ice-dependent Adelie penguins, increases in ice-tolerant gentoo and bridled penguins, changes in community phytoplankton and zooplankton composition, and changes in krill recruitment, abundance and availability to predators.