The world's biggest iceberg is drifting towards the Atlantic Ocean after being stuck near Antarctica.
A frozen block of ice far bigger than Greater London is captured in a vast pool of rotating water.
Another big iceberg breaks from in front of the UK's Halley research base - the third in three years.
UK researchers want to understand what triggers the Antarctic to kick out city-sized blocks of ice.
It may be bigger than a large city - but the world's biggest iceberg can still turn on a sixpence.
The world's biggest iceberg, A23a, is experiencing rapid decay as it moves through the Southern Ocean.
Scientists use a radar satellite to take a "tape measure" to the world's biggest block of ice.
The UK's polar research vessel visits A23a, an iceberg that's more than twice the size of London.
A giant ice block more than twice the size of Greater London is on the move, years after its formation.
