Submarine to delve under glacier

A yellow robot submarine will dive under an ice shelf in Antarctica to seek clues to world ocean level rises in one of the most inaccessible places on earth.

The 7-meter submarine, to be launched from a US research vessel, will probe the underside of the ice at the end of the Pine Island glacier, which is moving faster than any other in Antarctica and already brings more water to the oceans than Europe's Rhine River.

Scientists have long observed vast icebergs breaking off Antarctica's ice shelves - extensions of glaciers floating on the sea - but have been unable to get beneath them to see how deep currents may be driving the melt from below.