A trillion-ton iceberg has broken off the West Antarctic ice shelf, scientists monitoring the growing crack have revealed. The 2,200 square mile section of the Larsen C ice shelf snapped off between Monday and today, the team at Swansea University said.

While such cracks happen periodically – and this one is believed to have been a natural event – experts are also watching to see whether the process has been affected or accelerated by global warming. Researchers at the university had warned in June that the vast iceberg was “hanging by a thread” and close to breaking off.

The breakaway iceberg – more than a quarter of the size of Wales – changes the landscape of the peninsula forever, scientists said. The release of the new iceberg – called calving – was detected by a NASA satellite. It has reduced the size of the Larcen C ice shelf by 12% and experts fear it may disintegrate like its neighbouring Larsen B ice shelf did in 2002.