A 1 trillion-tonne iceberg–one of the biggest ever recorded–calved away from the Larsen C Ice Shelf in Antarctica earlier this month. Its volume is twice that of Lake Erie.

It was already floating before it calved away, so it has no immediate impact on sea level. Although the remaining ice shelf will continue to regrow naturally, Swansea researchers have previously shown that the new configuration is potentially less stable.  There is a risk that Larsen C may eventually follow the example of its neighbor, Larsen B, which disintegrated in 2002 following a similar rift-induced calving event in 1995.

If the shelf loses much more of its area, it could result in land-based glaciers speeding up their passage toward the ocean. This nonfloating ice would have an eventual impact on sea levels at a modest rate.

Caption: Map of Larsen C, overlaid with NASA MODIS thermal image from July 12, 2017, showing the iceberg has calved.