Ecowatch published an informative article about a huge iceberg, roughly 115 square miles, that has calved off of the Pine Island Glacier. The article cites an interesting series of posts by Stef Lhermitte discussing a large new iceberg, designated B-46, which is rapidly disintegrating as it drifts toward the Pacific Ocean.
The series of posts includes a GIF slideshow showing annual sea-ice extent at the Pine Island Glacier. Here is a scrollable PDF showing a series of screencaps taken from the GIF slideshow, with images at roughly a 5-year interval from 1975 to 2018 (depending on what years had available images). The sea ice extent for each year is indicated by a color-coded thick line; over time, this line progresses upward, exposing more of the seawater below. In the background of all images, the satellite image appears to be current, as taken on 10/30/2018.
Click on the image below for a scrollable view; the PDF file may be downloaded.
Overall, this series of images shows a pronounced decline in sea-ice coverage. Within the images, you will also notice that there were a few years, ending in 2013, where sea-ice cover was expanding. Since 2013, the melting/calving has been precipitous. Bear in mind, the polar regions are in total darkness for months each year, and it may take years for new meltwater to mix with the seawater below. Thus, massive ice melting may cause an easily frozen freshwater lens to sit atop the seawater. This will create an illusion of expanding sea-ice extent for a few winters. But, eventually, once the excessive freshwater becomes mixed, or as ambient air temperatures continue to increase, the expanded ice that peaked in 2013 will become just a distant memory.
Putting this in a Geographic Context
Here is an excerpt from Wikipedia, describing this specific glacier:
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica’s ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.
The area drained by Pine Island Glacier comprises about 10% of the West Antarctic Ice Sheet. Satellite measurements have shown that the Pine Island Glacier Basin has a greater net contribution of ice to the sea than any other ice drainage basin in the world and this has increased due to recent acceleration of the ice stream.
Here are a pair of images, showing Pine Island Glacier’s location on Antarctica, and showing the seas that surround Antarctica, connecting it to the extreme southern oceans.
What Does this Suggest for Our Global Future, and for Aviation?
The rate of calving in recent years is disturbing, and reflects a harsh reality: if our ever-expanding over-consumption of fossil fuels is not reined in, and we continue to see 2- or 3- ppm annual increases in average atmospheric CO2 concentrations (see Keeling Curve), we can expect collapse of these polar glaciers and large-scale sea-rise. Hundreds of the busiest airports across the globe will become underwater. Homes for more than a billion people will also become uninhabitable, under sea-rise. Displaced people will need to find new homes, and that situation will result in global conflict and likely massive human depopulation.
Would it not be a good idea to immediately impose policies that strongly disincentivize excessive and arbitrary use of aviation?
A Closing Image: Accelerated Melting is Likely
Below is a different perspective, rotated, but showing the recession of the glacier (roughly from left to right) and how it compares to actual shorelines beneath. The areas of ice over water are designated as the ‘northern ice shelf’ and ‘southern ice shelf’. Over land, colors appear to show ice flow rates using a spectrum, with red being fast, yellow being moderate, and blue being slow. A major concern among scientists who study polar ice loss and related sea-level rise is that loss of sea-ice eventually removes an important ‘plug’ that holds back glacial ice over land; kind of like eroding the footing out from under a bridge pier. In other words, in this example, the fear is that once the Pine Island Glacier recedes beyond the base of the SW tributary and the southern ice shelf is nearly gone, ice flow from the SW tributary will rapidly accelerate, which in turn will rapidly accelerate global sea-level rise.
It would seem to be very foolish, to continue to ignore this evidence.