Happy New Year 2024 (and sorry for the forum being offline some hours) /DM
Quote from: theoldinsane on May 16, 2016, 07:09:45 PMQuote from: AbruptSLR on May 16, 2016, 06:43:24 PMQuote from: theoldinsane on May 16, 2016, 06:29:32 PMI guess that if the shelf is thicker than the island it will be another outcome compared to if the shelf and the island are of near equal thickness. Maybe anyone of the experts can comment? Anyway, it is exciting and maybe interesting for future bigger events of its kind.I point-out that another major calving event will occur for the PIIS along existing crevasses; it is only a question of when, and what will trigger such a calving (as impacting the grounded iceberg is not a requirement for such a major calving event).Yes, but suppose you at some point in the future have a lot of grounded islands at the same time. Will they slow down the shelf via some kind of buttress effect (negative feedback) or will they help to speed up the calving through "change the compressive stress field in the PIIS" (positive feedback). Or has it no significance?Each case is different. While potential buttressing from a mélange is real, it is also temporary, and the amount and influence of the buttressing is dependent on geometry and dynamics.
Quote from: AbruptSLR on May 16, 2016, 06:43:24 PMQuote from: theoldinsane on May 16, 2016, 06:29:32 PMI guess that if the shelf is thicker than the island it will be another outcome compared to if the shelf and the island are of near equal thickness. Maybe anyone of the experts can comment? Anyway, it is exciting and maybe interesting for future bigger events of its kind.I point-out that another major calving event will occur for the PIIS along existing crevasses; it is only a question of when, and what will trigger such a calving (as impacting the grounded iceberg is not a requirement for such a major calving event).Yes, but suppose you at some point in the future have a lot of grounded islands at the same time. Will they slow down the shelf via some kind of buttress effect (negative feedback) or will they help to speed up the calving through "change the compressive stress field in the PIIS" (positive feedback). Or has it no significance?
Quote from: theoldinsane on May 16, 2016, 06:29:32 PMI guess that if the shelf is thicker than the island it will be another outcome compared to if the shelf and the island are of near equal thickness. Maybe anyone of the experts can comment? Anyway, it is exciting and maybe interesting for future bigger events of its kind.I point-out that another major calving event will occur for the PIIS along existing crevasses; it is only a question of when, and what will trigger such a calving (as impacting the grounded iceberg is not a requirement for such a major calving event).
I guess that if the shelf is thicker than the island it will be another outcome compared to if the shelf and the island are of near equal thickness. Maybe anyone of the experts can comment? Anyway, it is exciting and maybe interesting for future bigger events of its kind.
From a layman's perspective, as the glacier retreats it seems we should expect larger icebergs in the future in terms of height, therefore maybe more groundings for longer times, which might disrupt the circulation of ocean water around and under the glacier and even potentially pose as a negative feedback. Just a thought here. "in situ calving"
Quote from: oren on May 16, 2016, 09:05:41 PMFrom a layman's perspective, as the glacier retreats it seems we should expect larger icebergs in the future in terms of height, therefore maybe more groundings for longer times, which might disrupt the circulation of ocean water around and under the glacier and even potentially pose as a negative feedback. Just a thought here. "in situ calving"Numerous marine glaciers (like Jakobshavn) have already lost their ice shelves; and during those occurrences what you are describing did not occur. Rather, basal melting due to warm ocean water thinned the ice shelves (as did ice flow velocity), until the calving events reached the grounding line. After that cliff failures limited the size of the associated icebergs, which also frequently roll, resulting in reduced drafts.
Not quite there yet (or so it looks to me)
The higher resolution IW images are better, even when scaled from 10 m/pix to 30 m/pix.
Anyway, no unambiguous deformation of the ice island visible.
Thanks. I've been 'seeing things' (cracks, I contend) on the low-res image pairs, some of which match your hi-res image pairs (but they don't all match). Time will tell which are phantom and which are physical.
A large chunk breaks off the island. Looks like break up will come pretty soon.Dates are May 30 and Jun 11
In the same time frame another calving on the other side of the glacier.
Looks more like a rotation event than breaking free. Jun 30 vs Jun 11
Quote from: solartim27 on June 30, 2016, 11:31:51 PMLooks more like a rotation event than breaking free. Jun 30 vs Jun 11It might still be pinned against translation & only free to rotate about the pinning point.
This Modis mosaic dated 20160711
Looks to me as though a crevasse is extending toward the point of rotation and another is extending in a pattern that would separate the pinning point from the rest of the berg. Both crevasses are either racing thinning to free the berg by breaking it up, or they are products of thinning.Any guesses as to when the berg will drift free?
Looks to me as though a crevasse is extending toward the point of rotation and another is extending in a pattern that would separate the pinning point from the rest of the berg. ...
More rotation and advance.
What a tease.
