As part of the International Polar Year, Polar Discovery brings you the stories of science on ice. The polar regions are experiencing unprecedented environmental changes that are having significant impacts on global climate, ecosystems, and society. Using the latest engineering advancements, scientists are studying the changing climate at the heart of the icy Arctic Ocean, the melting glaciers of Greenland, and the creatures of Antarctica's Southern Ocean.

Susan Humphris describes where CTDs (Conductivity-Temperature-Depth oceanographic instruments) and the autonomous vehicle Puma have been deployed on the Gakkel Ridge to locate volcanoes and hydrothermal vents.

On Day 36 of Polar Discovery's third expedition, we were nearing the edge of the ice pack, which means we were also entering bear country. We saw nine in a 24-hour period, beginning Saturday evening. In the United States, we call them "polar bears," but that's a bit misleading because they don't exist at the southern pole.

Andrea Burke, a second year graduate student in the MIT/WHOI Joint Program discusses her interest in paleoceanography, past climate change, and her excitement about going to Antarctica to learn more.