Researchers have discovered that a deep-ocean current is carrying frigid water rapidly northward from Antarctica along the edge of a giant underwater plateau. The current is very fast, moving at speeds greater than 700 metres per hour, and "carrying volumes as high as 30 million cubic metres per second. This is significant because it represents a "fast lane" by which climatic and environmental changes affecting the Southern Ocean can propagate northward, says Alejandro Orsi, a physical oceanographer