Support the Arctic Sea Ice Forum and Blog

Author Topic: Some Recent History of the destruction of the WAIS  (Read 7350 times)

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Some Recent History of the destruction of the WAIS
« on: November 01, 2013, 04:04:37 AM »

In 1968 John Mercer, a glaciologist at Ohio State University, pointed out a problem with the West Antarctic Ice Sheet the WAIS, this is a smaller, but still enormous, mass of ice, separated by a mountain range from the bulk of the continent. Adventures who had traversed the ice during the International Geophysical Year 1957-58 had shown that much of the base of this mass was below sea level. Mercer argued that it was held back from flowing into the ocean, in a delicate balance, only by the shelves of ice floating at its rim. These shelves might disintegrate under a slight warming. The much larger mass of ice corked up by the shelves would then be released to slide into the ocean and disintegrate into icebergs. Just so, Mercer suggested, a collapse of ice sheets into the Arctic Ocean might have caused the more local, but remarkably sudden, cooling of the North Atlantic around 11,000 years ago that other scientists had identified. A West Antarctic Ice Sheet collapse could be very rapid, Mercer said. The sea level would not rise as far as it would rise if all of Antarctica surged, but it would be bad enough — up to five meters, he estimated (16 feet; calculations decades later pinned down the number at
around 11 feet). Much of the world's population lives near the shore. Such a rise would displace more than a billion people and force the abandonment of many great cities. Mercer thought it could happen within the next 40 years

Mercer published his worries in an obscure conference report, and although he wrote forcefully, he did not push his views on colleagues in the personal encounters that are crucial in a small community of specialists. The few specialists who heard of his ideas were not impressed. The problem, one of them complained, "could be argued indefinitely if it is not quantified.”

Glaciologists had been working for decades on ways to calculate numbers for the flow of ice masses. In the 1970s they made rapid progress in formulating abstract mathematical models and putting the powerful new computers to work. The calculations, with many approximations, suggested that the West Antarctic Ice Sheet was indeed unstable. Apparently the floating ice shelf that held it back could break up with surprising ease, and the whole mass might begin sliding forward. One scientist who made a landmark calculation, Johannes Weertman, concluded that it was "entirely possible" that the West Antarctic Ice Sheet was already now starting its surge

I was a little surprised when I found this report, as I had never, over the years heard of such a thing.

It appears Mercer’s prediction of forty years may be off a decade or two, but at this point, seems unstoppable.

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #1 on: November 01, 2013, 06:41:39 AM »
Mercer saw quite clearly the rape of things to come. I see I have been remarking on the Mercer prediction of the Weertman instability since 2007.

http://www.realclimate.org/index.php/archives/2007/07/making-sense-of-greenlands-ice/comment-page-1/#comment-36876

referring to doi:10.1038/271321a0
all those shelves he told us to watch for are long gone ...

some more thoughts at

http://membrane.com/sidd/antarctica-awakes/

sidd

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: Some Recent History of the destruction of the WAIS
« Reply #2 on: November 01, 2013, 08:29:02 PM »
Wow!  Thanks sidd.

That's some web site you referred me to, I enjoyed that.  Learned a lot too.

I'm still kinda new at this and was amazed when I tripped over the info on Mercer and Weertman.

Much of the gw issue has come to light for me over the last several years as the ice melt in the Arctic has been well published.  Even before that, when in 2000, B-15 calved off the Ross ice shelf
and the language used by the scientific community to described the event set off some bells.
I was not to far away physically when that occurred, as I was circumnavigating in my smallish sailing vessel, and happened to be below the Antarctica circle.

My understanding of climate change has vastly improved since I found this web site, it has been most illuminating.  Being a global armature sailor, climate driven weather has been a hobby of mine for decades.

Anyway, Thanks again

Best,
Bligh
 

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #3 on: November 02, 2013, 05:31:29 AM »
glad to help. look at AbruptSLR postings and threads in this forum for detail.

but let me ask something off topic. You seem to be a sailor, with some experience of the Southern Ocean. Would you consider writing of your experiences, probably a new thread in the "The rest" section or a "Southern Ocean" generic thread might be better. I shall look forward to it, and imagine others might also.

sidd

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: Some Recent History of the destruction of the WAIS
« Reply #4 on: November 02, 2013, 05:18:48 PM »
Sidd,

I have read, with a keen interest,  most of the threads concerning the WAIS, some of them several times, All in an effort to fully understand the dynamics of the collapsing Ice shelves. I’ve always felt that the western portion of Antarctica would take the brunt of change due to the powerful wind patterns driving the Ocean waters East in that part of the Globe. What I did not understand, and learned here, was that the vast majority of the excessive heat was being absorbed by the Oceans. Like I said, I’m kind new at the scientific end of the stick.
What I’m not new at is observation, having spent years out sailing the Globe I’ve become increasingly concerned about the health of the Planet. From the endless chain of observable pollution to the unseen tiny bits of plastics floating in the top several feet.
These tiny bits of plastics cannot normally be seen by the untrained eye and are not observable by satellite, it is this that is killing marine life all over the Globe.  It use be that one could drag a fine mesh-net behind his sailing vessel and collect Gruel, a mixture of tiny animals that were edible and made a fine addition to a home brewed stew. No more, as the vast & nutrient rich Southern Oceans are dieing, full of chemical sludge, oil balls, tar and other floating debris.
Perhaps as I become more comfortable in this “Science” based forum I’ll have some more meaningful insights to add based on my sailing experiences.

Best.
Bligh

 

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #5 on: November 03, 2013, 01:01:23 AM »
"These tiny bits of plastics cannot normally be seen by the untrained eye and are not observable by satellite, it is this that is killing marine life all over the Globe.  It use be that one could drag a fine mesh-net behind his sailing vessel and collect Gruel, a mixture of tiny animals that were edible and made a fine addition to a home brewed stew. No more, as the vast & nutrient rich Southern Oceans are dieing, full of chemical sludge, oil balls, tar and other floating debris."

I agree with you that humans are killing the oceans by treating it like a sewer, and I grieve with you also. I fear we all live downstream now, and the host  of ills we have burdened the good earth with will return upon our heads and kill us, indeed it is already doing so.

The second sentence in your para quoted above is fascinating, I had no idea.

Out of curiosity, on your voyages did you ever have a ship's cat ?

sidd

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: Some Recent History of the destruction of the WAIS
« Reply #6 on: November 03, 2013, 04:42:43 AM »
sidd…

Another Cat lover? I’ve always had a cat and considered that out to Sea a cat would make fine company, perhaps my next voyage, as even in harsh conditions, cats remain terminally cool.  In the Gruel….the tiny baby shrimp were the best…..nothing better on a cold night.
I’ve wandered too far off topic, cats and sailing in a WAIS thread?  Perhaps your suggestion was correct, a different thread entirely might be more appropriate.


fair winds
bligh


 

ggelsrinc

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #7 on: November 03, 2013, 06:31:18 AM »

In 1968 John Mercer, a glaciologist at Ohio State University, pointed out a problem with the West Antarctic Ice Sheet the WAIS, this is a smaller, but still enormous, mass of ice, separated by a mountain range from the bulk of the continent. Adventures who had traversed the ice during the International Geophysical Year 1957-58 had shown that much of the base of this mass was below sea level. Mercer argued that it was held back from flowing into the ocean, in a delicate balance, only by the shelves of ice floating at its rim. These shelves might disintegrate under a slight warming. The much larger mass of ice corked up by the shelves would then be released to slide into the ocean and disintegrate into icebergs. Just so, Mercer suggested, a collapse of ice sheets into the Arctic Ocean might have caused the more local, but remarkably sudden, cooling of the North Atlantic around 11,000 years ago that other scientists had identified. A West Antarctic Ice Sheet collapse could be very rapid, Mercer said. The sea level would not rise as far as it would rise if all of Antarctica surged, but it would be bad enough — up to five meters, he estimated (16 feet; calculations decades later pinned down the number at
around 11 feet). Much of the world's population lives near the shore. Such a rise would displace more than a billion people and force the abandonment of many great cities. Mercer thought it could happen within the next 40 years

Mercer published his worries in an obscure conference report, and although he wrote forcefully, he did not push his views on colleagues in the personal encounters that are crucial in a small community of specialists. The few specialists who heard of his ideas were not impressed. The problem, one of them complained, "could be argued indefinitely if it is not quantified.”

Glaciologists had been working for decades on ways to calculate numbers for the flow of ice masses. In the 1970s they made rapid progress in formulating abstract mathematical models and putting the powerful new computers to work. The calculations, with many approximations, suggested that the West Antarctic Ice Sheet was indeed unstable. Apparently the floating ice shelf that held it back could break up with surprising ease, and the whole mass might begin sliding forward. One scientist who made a landmark calculation, Johannes Weertman, concluded that it was "entirely possible" that the West Antarctic Ice Sheet was already now starting its surge

I was a little surprised when I found this report, as I had never, over the years heard of such a thing.

It appears Mercer’s prediction of forty years may be off a decade or two, but at this point, seems unstoppable.

I think John Mercer would agree with me now that all ice sheets are unstable and the accurate concepts of Milankovitch Cycles and ice ages weren't fully understood in 1968. Ice isn't stable in a Snowball Earth or any situation on Earth where it can become thick enough to have plastic properties and flow under it's own weight.

My question is was there data on the ages of the ice shelves John Mercer predicted were unstable and did he know about such data at that time, if it exists even after his predictions? I don't find losing the ice shelves that have been lost surprising in hind site, but his prediction weren't my hind site. IIRC, the Ellesmere ice shelf was around 3,000 years old and Larsen B was around 10,000 year old. It would also be useful to name the ice shelves, John Mercer predicted were unstable and when they broke away, I'm not claiming the two I mentioned where part of them, if it isn't obvious. I vaguely recall several of the names, but have never researched it in detail.

It isn't surprising global warming will cause ice shelves in the Arctic (I use capital) and Antarctic peninsula to break up, so I was wondering has anyone made a comprehensive list of known ice shelf break ups and ages of the world's ice shelves? Like glaciers, it would be a useful proxy to prove global warming. My logic is, I expect ice shelves to break up under any conditions, but does it make sense so many have broken up in the near present and what are the chances of that statistically happening without global warming? I think the same logic can be applied to glacier mass balance and retreat around the world.

The advantages I see in using ice shelves as a proxy for global warming is they can be aged to prove they have been around for such a long period of time and their number is so limited. When combined with area lost, what is totally left on the Earth, and their locations, it becomes a very convincing argument. I don't expect the major ice shelves of Antarctica to fall apart in the near future, but the canaries of the world's ice shelves will die faster than they can be reborn of equal size, without a doubt.

It's just a thought.

My knowledge of some recent history of the destruction of the WAIS is certainly less than what is often posted in this forum and covered as it's happening, unless we are talking about things that happened recently in geological time. Many of those discussions exist in this forum and I don't want to go off subject with your thread, which is easy for me to do.   

 

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #8 on: November 04, 2013, 05:47:00 AM »
"One warning sign that a dangerous warming is beginning in Antarctica, will be a breakup of ice shelves in the Antarctic Peninsula just south of the recent January 0C isotherm; the ice shelf in the Prince Gustav Channel on the east side of the peninsula, and the Wordie Ice Shelf; the ice shelf in George VI Sound, and the ice shelf in Wilkins Sound on the west side"

the quote is from doi:10.1038/271321a0 Mercer, Nature, vol. 271, p321, (1978)

the recent history of those ice shelves in outlined at the following link

http://membrane.com/sidd/antarctica-awakes/

sidd




bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: Some Recent History of the destruction of the WAIS
« Reply #9 on: November 04, 2013, 04:06:24 PM »
Thanks sidd

And thanks for your empathetic words….”And I grieve with you also”. It truly is heart wrenching when I see what has become of the Oceans. I did read your “links” and found them both fascinating and disturbing at the same time.. a logic that’s easily followed.

I’m out of my element here, all this electronic noise, all this scientific knowledge. In my world I’ve seen gw at it’s finest…coral reefs that I dove on (scuba) deep cut reefs, perhaps 15ft of vertical relief, a million billion multi colored fish. Tiny things, as a mother fish 2in long hovering over her babies, hiding in a shallow cut, drifting slightly within a pulsating current, protecting her young ones. Gone, just gone…those reefs all over the world, more so in some areas than others have changed to a mound of a ugly gray colored ash, bleaching I think they call it. And the beautiful fish …gone.

I use to think all of this was the changing acidity within the Oceans. But now understanding the rise in temperatures as well, adds a new dimension to an already complex equation. 

I sailed north 3 days ago, perhaps thirty miles to just south of NYC’s lower harbor, to a marina and set my vessel on the hard for maintenance work.  In route I encountered
three separate pods of Dolphins, small pods, perhaps no more than five animals each.
They weren’t right, they did not act right…they were sluggish, slow and uninterested in the world around them.  In contrast to what I’ve seen the deep Southern Oceans where
A pod might be of thousands in numbers, a half mile long and have the leader turn about and join with Horizon (my s/v) a great number would follow, they would play like children in the surf, most left within hours, however some stayed and left one by one over the next day or so, only to rejoin their pod I’m sure. I’ve sat on the aft deck of Horizon and slapped the hull as a large Dolphin approached, watched in amazement as they rolled on their side and gazed at me with those large black eye’s, wondering, I thought “Did I know what they did?”…. Anyway, enough, Horizon awaits there’s work to be done.

Best,
Bligh

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #10 on: November 05, 2013, 05:15:14 AM »
I am headed toward NYC and philly next week. would love to meet, send me a message (i think this forum allows messages) if your schedule allows a window. I will be on the road, so my reply may be slightly tardy.

sidd

ggelsrinc

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #11 on: November 05, 2013, 06:30:35 AM »
"One warning sign that a dangerous warming is beginning in Antarctica, will be a breakup of ice shelves in the Antarctic Peninsula just south of the recent January 0C isotherm; the ice shelf in the Prince Gustav Channel on the east side of the peninsula, and the Wordie Ice Shelf; the ice shelf in George VI Sound, and the ice shelf in Wilkins Sound on the west side"

the quote is from doi:10.1038/271321a0 Mercer, Nature, vol. 271, p321, (1978)

the recent history of those ice shelves in outlined at the following link

http://membrane.com/sidd/antarctica-awakes/

sidd

I know you know your Mercer and WAIS, both here and on RC. By any chance, do you know if the ice shelves Mercer mentioned were ever dated or the glaciers feeding them? Is there an easy way to determine or a previous study of both past and present ice shelves, that could be used to support global warming statistically? Data like size, age, location and loses! Those canary deaths can't be considered natural events.

sidd

  • Young ice
  • Posts: 4987
    • View Profile
  • Liked: 387
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #12 on: November 06, 2013, 06:44:35 AM »
Sorry, I don't recall seeing any dating of those shelves. I would look harder, but my time is currently limited for the next few weeks. If I find or recall something I shall certainly let you know.

sidd

ggelsrinc

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #13 on: November 06, 2013, 06:56:14 AM »
Sorry, I don't recall seeing any dating of those shelves. I would look harder, but my time is currently limited for the next few weeks. If I find or recall something I shall certainly let you know.

sidd

No problem! Even an ice shelf that is history can have it's feed glaciers dated to prove it was at least so old. The world doesn't have that many past and present ice shelves and I think they're the perfect canary to prove global warming.

It's just a thought!

Stephen

  • Frazil ice
  • Posts: 113
    • View Profile
  • Liked: 13
  • Likes Given: 0
Re: Some Recent History of the destruction of the WAIS
« Reply #14 on: November 13, 2013, 06:38:19 AM »
....
I agree with you that humans are killing the oceans by treating it like a sewer, and I grieve with you also. I fear we all live downstream now, and the host  of ills we have burdened the good earth with will return upon our heads and kill us, indeed it is already doing so.
......
sidd

There's more to it than that.  Your comment about "humans are killing the oceans by treating it like a sewer" infers that deliberate dumping is the main problem.   But the Japanese Tsunami and the very recent Typhoon through the Phillippines, which resulted in massive Tsunami-like surges, both push massive amounts of plastic into the oceans. Nothing deliberate about those events, but it illustrates the point that anything that can float and be carried by water will find its way into the ocean eventually.
The ice was here, the ice was there,   
The ice was all around:
It crack'd and growl'd, and roar'd and howl'd,   
Like noises in a swound!
  Rime of the Ancient Mariner by Samuel Taylor Coleridge

Bruce Steele

  • Nilas ice
  • Posts: 1476
    • View Profile
  • Liked: 140
  • Likes Given: 10
Re: Some Recent History of the destruction of the WAIS
« Reply #15 on: November 14, 2013, 12:51:24 AM »
Bligh8, on post#9 you mentioned odd behavior in Porpoise along the Atlantic seaboard. There is an
ongoing "unusual mortality event" affecting bottle nose porpoise and spreading to other cetaceans along the mid-Atlantic coast of North America. If you noticed odd behavior maybe you were witness to sick animals.

 http://www.nmfs.noaa.gov/pr/health/mmume/midatldolphins2013.html


« Last Edit: November 14, 2013, 12:56:32 AM by Bruce Steele »

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: Some Recent History of the destruction of the WAIS
« Reply #16 on: November 14, 2013, 02:38:03 AM »
Hey Bruce

Yes that was just as casual observation, Thanks for that link, I've read several others about the suspected virus causing these events. It's just me getting tired of observing these kinds of things every time I venture into the Oceans.

Since I've been reading here on this web site my deepest fears about the health of the planet have been verified by the vast amount of scientific evidence I've seen.

Tonight on the evening news there was an excerpt about the calved portion of the PIG and fears that it may interfere with shipping. Odd I thought that a single event, just one of many caused  by humanity and our response was "it may hinder economical considerations" ..typical.

Bligh