Earth's tilt keeps the South pole away from the sun during the northern summer. Even during Antarctic summers, most sunlight reflects off snow instead of melting it. As Antarctica iced up, it became unlivable for most animals and plants. Seals and penguins migrate or travel to Antarctica during its warmer months from November to March. Many scientists think a warming Antarctic climate is induced by human activity.
Scientists link increasing greenhouse gases in the atmosphere to Antarctica's rising temperatures.
Already, satellite data from Radarsat are yielding vital clues. Radarsat maps also reveal how ice shelves, moving through riverlike ice streams, reach the ocean and splinter into icebergs. And when icebergs the size of Rhode Island break off and float away, scientists take quick notice. In 1911, driven by a team of Dogs, Norwegian explorer Roald Amundsen reached the South Pole. The white ice of Antarctica reflects most of the sun's light and heat.