Antarctica - Pinning point five collapsed, the sea ice barrier buttressing Thwaites and Pine Island Glacier.
Antarctica has been under heavy cloud cover, so NASA's Worldview coastline images are rare. Kris Van Steenbergen is relentlessly researching climate impacts in the Southern Ocean and West Antarctica. He may sound familiar as he broke the news of a massive iceberg wedged on a sea mountain in front of the Thwaites Glacier for 20 years finally lifted off due to warming ocean currents. I created several diaries sharing many of his tweets and researched what could go wrong in the highly vulnerable Amundsen Sea Bay as best I could.
Iceberg B22a freed itself and tore away in December of 2022 from the Thwaites Glacier's front, leaving the floating tongue (ice stream) vulnerable to wave activity, year-round Pine Island sea ice laden cyclonic gyre, year-round melting and cheeseification of the glacier underbelly, and further fragmentation from relentless storms.
No news source reported the finding, and I still haven't seen any since, as far as I know. Six months later, in April, NASA reported the news of Iceberg B22A drifting away but did not discuss what the consequences of its absence may be.
Thwaites has only been studied since 2017 and is one of the most formidable places on earth. This is why I often refer to a rhetorical question of mine: Where is the Media? How can we demand action if this news is ignored, buried, or banned? That deglaciation event was a big fucking deal, to borrow from President Biden's glee on the Affordable Care Act passage.
With its plug still intact but threatened by warm water upwelling, the Ice Tongue prevents the majority of West Antarctica land and undersea ice from collapse and seabed displacement, respectively. The changes are profound and terrifying. The land-fast ice is gone in front of PIG and Thwaites before the melt season begins. This is not going to end well.
Update from Kris Van Steenbergen (yeah, he saw my diary, how cool is that): Replying to @icy_pete What I meant is that there's no land-fast buttressing sea ice left in September. The eastern flank lost pinning point 5 a few days ago.Also the icebergs that were blocking the western flank are gone (B22a, B45, B28, B29, ...).
You can see the damage by clicking on the NASA worldview links in Kris's tweets. I looked at the Amundsen Sea Embayment yesterday, and there was a ton of open water where the sea ice barrier once was. I can't prove it, as I still have not figured out how to save and post a Worldview image that does not turn into a thumbnail. But creating a movie on Worldview over the past couple of weeks clearly shows the breakup and loss of the sea ice barrier.
Pinning point five is no longer there according to Nasa's worldview. The loss of the sea ice barrier will affect both Pine Island Glacier and the eastern flank of the Thwaites Ice shelf. Will it lead to the breakup of the tongue anytime soon? Possibly.
The entire glacial area Kris refers to is the Amundsen Sea Embayment in the western Antarctic, which would raise sea levels by 10 feet if the Thwaites ice platform and plug were to collapse. It would take the rest of West Antarctica (Thwaites alone holds two feet of SLR) with it, but I have not seen any evidence from those studying this fuckery that the Thwaites collapse will happen this year. But, the remaining pinning points that stabilize the glacial tongue can all be lost in November and December of 2023, according to Kris Van Steenbergen.
Sea level rise would happen quickly not from the floating shelf itself but from the weight loss of the glacier pressing down on the sea bed, which keeps it below sea level. It is the rebound of the ocean bed, which would displace the water and flood coastlines. Richard Alley shared a 1970s grainy video that can act as a comparison to what a W Antarctic collapse would look like. It's long but fascinating and will be seared into your brain forever.
And then there are these tweets; you may want to grab a drink first.
