BOULDER, Colo., Feb.

New rifts have developed on the Wilkins Ice Shelf that could lead to the opening of the ice bridge that has been preventing the ice shelf from disintegrating and breaking away from the Antarctic Peninsula.

Wilkins Ice Shelf has experienced further break-up with an area of about 160 km² breaking off from 30 May to 31 May 2008. ESA’s Envisat satellite captured the event – the first ever-documented episode to occur in winter.

December's great Sumatra-Andaman earthquake - the most powerful in more than 40 years and the trigger of a devastating tsunami - shook the ground everywhere on Earth's surface. Weeks later the planet was still trembling. It was the first of its size to be measured and studied by the new worldwide array of digital seismic instruments.