Pine Island Glacier will dump yet another 96 square mile iceberg into the Amundsen Sea.

FYI

No one else has reported on this yet but, another massive chunk of ice will soon break off of West Antarctica’s Pine Island Glacier.

Pine Island is crumbling rapidly, it is located adjacent to the very vulnerable Thwaites ice stream, both of which drain into the Amundsen Sea embayment. Pine Island is configured in such a way that it is susceptible to thinning and disintegration. The ice stream has developed a troubling new way of losing ice, with rifts forming in the center of its floating ice shelf from beneath, rather than from the sides. Pine Island last calved a major iceberg on November 7, 2018.

Last week, Antarctica’s Pine Island Glacier calved a massive iceberg, B-46, into the Amundsen Sea. https://t.co/NZlNvh6bI2pic.twitter.com/p8slkJBFC1

The ice sheet in this area is grounded 6500 feet below sea level, which makes it more exposed and vulnerable to rapid melting at its base from warm ocean water, and to the rapid retreat of the grounding line.

It is not uncommon for the fast-moving glacier to calve an iceberg every 10 years or so, but recently the frequency has been just a few months. Smaller bergs break off even more frequently.

Looks like Pine Island Glacier is getting ready for another major calving event, with a new crack developing about 10 km away from the front. The resulting iceberg could be about 250 sq. km, comparable to Iceberg B-46 formed in the October 2018 event. pic.twitter.com/fPekUn9cL0

From Scientific American:

Antarctica's Pine Island Glacier holds a dubious honor—it is currently the largest Antarctic contributor to global sea-level rise, thanks to the enormous amount of ice it has lost in recent decades. Now scientists have identified the likely cause of some of the glacier's most spectacular calving events, which have birthed icebergs several times the size of Manhattan.

The culprit: submerged rock ridges that poke up high enough to occasionally hit the bottom of the glacier. This activity creates small cracks that grow and eventually cause massive chunks of ice to break off. But the undersea rocks are not all bad news—they can also help stabilize the glacier by grinding against its underside, buttressing it against flowing faster out to sea.

.@NASA_Landsat shows the first optical high-resolution image (15/30m) of iceberg B-46 after its calving from Pine Island Glacier on 29 Oct 2018. The image shows clearly how it fragmented into multiple pieces like iceberg B-44 did in 2017. pic.twitter.com/fmvzQnTdNS