Once a rapidly spreading rift intersects with another fissure, an iceberg of at least 660sq miles is set to be loosened, Nasa says
An iceberg roughly twice the size of New York City is set to break away from an Antarctic ice shelf as a result of a rapidly spreading rift that is being monitored by Nasa.
A crack along part of the Brunt ice shelf in Antarctica first appeared in October 2016, according to the National Aeronautics and Space Administration (Nasa). The crack is spreading to the east. This rift, known as a Halloween crack, is set to intersect with another fissure that was apparently stable for the past 35 years but is now accelerating north at a rate of around 2.5 miles a year.