The world's largest iceberg, A23a, is on the move after being trapped in place off Antarctica's coastline for almost 40 years. The gigantic "ice island," which is three times the size of New York City, will likely drift into the "iceberg graveyard," potentially putting it on a collision course with an important penguin refuge before it fractures and melts away.
The berg, which has a surface area of around 1,550 square miles (4,000 square kilometers), was originally birthed in 1986 when it calved from the Filchner Ice Shelf. But the hefty berg got stuck soon after when its submerged keel became lodged on the seafloor in the Weddell Sea.
