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Antarctica Overview
Africa separated from Antarctica around 160 million years ago, and the Indian subcontinent drifted away on its collision course with Asia 125 million years ago. Roughly the time of the Cretaceous extinction that killed off the dinosaurs, Australia and New Guinea began to drift north, and the great ocean currents that moved from equator to pole and back had shifted to latitudinal currents, and Antarctica started to freeze. The freezing accelerated 23 million years ago when the Drake Passage opened up, and the Antarctic Sea became a non-mixing circulating current; the continent was completely icebound as of 15 million years ago, and its current extent of ice dates back to roughly 6 million years ago, with most of the life on the continent now ringing its coast. Broadly speaking, Antarctica is divided into the geologically young West Antarctica (which has its northernmost extension, with the Antarctic Penninsula), and East Antarctica, which has landforms that date back to three billion years or older – some of the oldest crustal rock on the planet is thought to lie under Antarctic ice. The Antarctic ice pack varies in depth, but is miles deep in some places. Most of Eastern Antarctica is at considerable altitude, nearly two miles high at the Antarctic Plateau, and that's before the ice sheet. Parts of Antarctica and their ice sheet qualify as some of the highest terrain on the planet. Climactically, Antarctica is cold and dry; it's so cold in the interior of the continent that it effectively gets no annual precipitation; it's too cold to snow in the interior in more than a few places, though the driving wind from the interior combining with wet, and (comparatively warm) air on the coasts can create snowstorms that drop a foot of snow per hour for two days! Politically, Antarctica is bound by the Antarctic Treaty of 1959, which prohibits any national claims and any mineral exploitation of the continent, and it's geared to preserve Antarctica's unique ecosphere. That treaty is set to expire in 1948, and there are several working groups attempting to extend it or make some elements of it permanent.
This is an original news article © The Kids Window
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