Antarctic sub measures sea ice

A novel autonomous sub has acquired the first detailed, high-resolution 3D maps of Antarctic sea ice.

Released from a ship, the vehicle criss-crossed the underside of ice floes, using upward-looking sonar to measure their shape.

The sub, known as SeaBED, was developed at the Woods Hole Oceanographic Institution (WHOI) in Falmouth, Massachusetts.

This footage shows one of the research missions undertaken by scientists.