The world's largest iceberg on a collision course with a remote island

The world's largest and oldest iceberg is on a collision course with a remote island... potentially putting wildlife in danger. Known as 'megaberg' the colossal slab of ice is drifting towards South Georgia - a British overseas territory - north of Antarctica. The iceberg first broke away from the Antarctic shelf in the 1980s. So how has it survived so long, and what could happen if it does reach the island?