A team of scientists on a NASA IceBridge shared video this week of a massive iceberg fell off of the Pine Island Glacier, the most recent calving event for the 68,000-square-mile glacier in Antarctica. Though they did not see the actual moment of breakage, the footage does help to illustrate the gigantic size of the this new iceberg, which is one of the larger events of its kind in recent memory.
Generally when an iceberg breaks away from a glacier— a process called calving — it is a sign that there’s some type of structural issue with the ice sheet. This is probably the case with the Pine Island Glacier, which has been thinning for the greater part of 25 years.
In this most recent event, spotted on Wednesday by NASA scientists, a massive rift of 115 square miles appeared, which later lead to a massive shedding of ice. This most recent event is the latest amongst a pattern of calving events at the Pine Island Glacier.
This new iceberg, called B-46, broke away from Antarctica’s Pine Island Glacier at the end of October, though we didn’t really get images of it until this week. When the rift first appeared, it was 115 square miles, which is about five times the size of Manhattan Island, but the largest individual iceberg is about 87 square miles.
When an iceberg the size of lower Manhattan shed from Greenland’s Helheim Glacier in July, the Washington Post reported that 10 billion tons of ice fell into the ocean.
However, this week’s event is still classified as another large calving event.
Size aside, there are other reasons to pause and reflect on the status of B-46. The Pine Island Glacier this has shed ice several times over only five years: once in 2013, once in 2015, and one in 2017, which adds up to an alarming amount of ice flow. Those icebergs don’t simply stay put: They can float into more populated waters. For example, ice shed from the Jakobshavn Isbrae glacier in Greenland is rumored to be responsible for sinking the Titanic in 1918.
The next pressing concern about these calving events is likely that they’ll contribute to sea level rise. NASA tweeted on Thursday that the Pine Island Glacier is the fastest melting glacier in Antarctica.