LONDON — A vast iceberg with twice the volume of Lake Erie has broken off from a key floating ice shelf in Antarctica, scientists said today.

The iceberg broke off from the Larsen C ice shelf, scientists at the University of Swansea in Britain said. The iceberg is described as weighing 1.12 trillion tons.

The process, known as calving, occurred in the last few days, when a 5,800-square-kilometer (2,240-square-mile) section broke away.

“We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometers of ice,” said Adrian Luckman of Swansea University. “We will continue to monitor both the impact of this calving event on the Larsen C Ice Shelf, and the fate of this huge iceberg.”

It was a natural event that wasn’t caused by man-made climate change, said Swansea glaciologist Martin O’Leary.

Nonetheless, “this puts the ice shelf in a very vulnerable position,” he said in a statement.

Scientists said the latest iceberg break won’t affect sea levels in the short term.