Happy New Year 2024 (and sorry for the forum being offline some hours) /DM
The 'monster' iceberg: What happened next?https://www.bbc.co.uk/news/science-environment-44745734
A-68A’s sluggishness is not surprising. When it calved, the berg was about the size of Delaware and weighed more than a trillion tons. Dense sea ice in the Weddell Sea has made it harder for currents, tides, and winds to move all of that mass. The iceberg has also become stuck at times when its north end encounters the shallow water near Bawden Ice Rise, an ice-covered rock outcrop.Still, Iceberg A-68A has seen plenty of motion. Throughout the year, tide cycles have shuffled the berg back and forth like a driver trying to get out of a tight parallel-parking spot. Its north end has been repeatedly smashed against Bawden Ice Rise, fracturing and reshaping its northern edge. Also notice how the southeastern edge appears to have grown in area. This is not part of the original iceberg; it is fast ice that has come fastened to the edge of the berg as it shoves through the ice pack.A-68A will continue this dance in moonlight, as the darkness of austral winter continues through early August. Thermal images ... an important tool for Adrian Luckman and the UK-based Project MIDAS, which has been monitoring the iceberg and how its calving affects the Larsen C Ice Shelf.There’s no telling how much longer A-68A will stay “stuck” in the Weddell Sea. The smaller A-68B is a good example of the path taken by many Antarctic bergs, as they are carried by currents out of the Weddell and northward toward South Georgia and the South Sandwich Islands.
..."Until recently, the iceberg was hemmed in by dense sea-ice in the east and shallow waters in the north. "Now, a strong foehn wind blowing eastwards off the ice shelf in early September has pushed the southerly end of the iceberg out into the Weddell Gyre. This persistent clockwise drift of ocean waters and floating sea-ice flowing north past the Larsen Ice Shelf has rotated A-68 out into the Weddell Sea. "Here, it is much more free to begin moving away and be carried further north into warmer waters."...
When A68 separated from the Antarctic ice shelf, it opened up a doorway into a pristine underwater ecosystem. Researchers predict this area of the ocean has remained undisturbed for some 120,000 years, but now that it’s exposed to sunlight and open-air conditions, there’s no telling what kinds of interesting changes could take place.“You’ll have sunlight, you’ll have phytoplankton, and you’ll begin to get zooplankton and fish in there pretty quickly,” marine ecosystem researcher Phil Trathan told Live Science in October. “So, it will be sort of a chain reaction — as you get productivity happening then you’ll get more species coming in, and so there will be quite significant changes over relatively short time scales.”
I think it is useful to show this little 35 pixel something in the bigger context.When Larsen C was about to calve I quickly calculated this effect on the ice extent around Antarctica. Its size (although it is a really big iceberg) is much too small to be presented in the two-digit daily JAXA figures.
Nice animation from Adrian Luckman:https://adrianluckman.wordpress.com/2018/09/05/iceberg-a68-escapes-into-the-weddell-gyre/
...Comparing with 19 July 2018 image above, A68-A has rotated about 50º in 6 weeks.
A-68A is from the orange shaped area and is now in the yellow shaped area.[forgive my poor drawing skills]
Quote from: RoxTheGeologist on July 13, 2017, 01:19:39 AMTime to lock this thread....?No. Where will it go? Will it break up? Who owns it?
Time to lock this thread....?
...Incidentially, today's PolarView offers the best image of the battering-ram caused (or assisted) cracks in Larsen C. ...
Is it grounded on the bottom left? Seems to be the point it is rotating about.Any idea what it will take to lit off and move with the current / wind?
...An additional 10º rotation, per yesterday's PolarView image, so 60º in 8 weeks.