This 2016 photo (click here) shows a rift that, within a few months, widened even farther and and released a Delaware-size iceberg from Antarctica’s Larsen C ice shelf. The rough surface of ice mélange is visible on one side of the rift.
Here's another reminder of the precarious position (click here) that the world's climate and ecosystems are in: a new study estimates that global warming could push the Antarctic ice sheet past a tipping point in as little as 10 years....
...As icebergs break off Antarctica, they float down a major channel known as Iceberg Alley. Debris released from these icebergs accumulates on the seafloor, giving researchers a record of history some 3.5 kilometers (2.2 miles) under the water.
By combining this natural logbook of iceberg drift with computer models of ice sheet behavior, the team was able to identify eight phases of ice sheet retreat across recent millennia. In each case, the ice sheet destabilization and subsequent restabilization happened within a decade or so.
The results published by the researchers augment modern satellite imagery, which only goes back around 40 years: they show increasing losses of ice from the interior of the Antarctic ice sheet, not just changes in ice shelves already freely floating on the water.
"We found that iceberg calving events on multi-year time scales were synchronous with discharge of grounded ice from the Antarctic ice sheet," says glaciologist Nick Golledge, from the Victoria University of Wellington in New Zealand.
The study showed the same sea rise pattern happening in each of the eight phases too, with global sea levels affected for several centuries and up to a millennium in some cases. Further statistical analysis identified the tipping points for these changes.
If the current shift in ice in Antarctica can be interpreted in the same way as the past events identified by the researchers, we might already be in the midst of a new tipping point – something we've seen in other parts of the world and the Arctic in recent years....
