The Polar Regions: Arctic and Antarctic

The Arctic is the region around the North Pole. It is mostly a frozen ocean — the Arctic Ocean — covered by a floating sheet of sea ice. The Antarctic is the region around the South Pole. Unlike the Arctic, Antarctica is an actual continent: a vast landmass buried under an ice sheet up to 4.8 kilometres thick. This is one of the most important differences in all of geography: the north is frozen sea, the south is frozen land.

The poles have the most extreme daylight on Earth. Because the planet is tilted, in the polar summer the Sun never fully sets, giving weeks of constant daylight known as the midnight Sun. In the polar winter the opposite happens: the Sun never rises, plunging the region into months of darkness. This single tilt of the Earth is what creates these astonishing long days and long nights.

Despite extreme cold, both polar regions teem with life. Polar bears, Arctic foxes, and walruses live in the Arctic. In Antarctica, penguins huddle against bitter winds, and the surrounding Southern Ocean is rich with krill that feed whales, seals, and seabirds. Animals here survive thanks to special adaptations: thick fur, layers of fat called blubber, and white coats that hide them against the snow.