More than twice the size of greater London, the expanse of ice is unpredictable and dangerous.

Measuring roughly 1,350 square miles (3,500 square kilometers) across, A23a is the world's largest and oldest iceberg ...

The world’s largest iceberg, A23a, is heading north from Antarctica toward South Georgia, a British Overseas Territory in the southern Atlantic Ocean. In the past, giant icebergs grounding near South ...

The world’s largest iceberg ‘A23a’ broke away from the Filchner Ice Shelf in 1986 and is now drifting northwards.

Millions of seals and penguins are threatened by a very large iceberg drifting toward their remote island in the South Atlantic. The giant iceberg, named A23a, is the world's largest iceberg ever ...

The world's biggest iceberg is on a collision course with a tiny island in the South Atlantic. The massive ice chunk goes by the unassuming name of A23a. NICK HOLSCHUH: A23a is huge, 1,400 square ...

A wall of ice the size of Rhode Island is lumbering toward a remote island off Antarctica that’s home to millions of penguins and seals.

A massive iceberg, known as A23a, is on an apparent collision course with South Georgia Island, a British territory in the South Atlantic Ocean. The giant sheet of ice, which originally broke off ...

The world's largest iceberg is on a collision course with a remote British island, potentially putting penguins and seals in ...

The world's biggest iceberg, known A23a, is on a collision course with a tiny island in the South Atlantic, which is home to millions of seals and nearly half the world's population of king penguins.