Shelf Temperature Profiles

[HotWarning]

As we analyze ourselves to certain doom it becomes imperative that we measure shelf temperatures in the form of a profile map. The only one I could find online is here:
ftp://ftp.nodc.noaa.gov/nodc/archive/arc0001/9800040/1.1/data/0-data/atlas/html/intro/intro_ks.htm

The figure is Figure 5:
ftp://ftp.nodc.noaa.gov/nodc/archive/arc0001/9800040/1.1/data/0-data/atlas/html/intro/graphics/ks_fig5.htm

This is old data (1994) but is the form I like to see.

A new research article is here:
http://www.homepages.ed.ac.uk/shs/Climatechange/Arctic%20ice/Big%20methane%20release.pdf

Can anyone refer me to temperature profiles of the different shelfs? Are we monitoring them? Seems that is more critical now that the ice is just about gone.

[Neven]

Welcome to the Forum, HotWarning. Your profile has been released.

I'm moving this thread to the Permafrost section.

[TerryM]

Didn't Cate post something about deep 11 c waters surging onto the shelves near Newfoundland?


I recognize that's south of our general areas of interest, but the extreme temperature caught my eye.


Terry

[Cate]

Didn't Cate post something about deep 11 c waters surging onto the shelves near Newfoundland?


I recognize that's south of our general areas of interest, but the extreme temperature caught my eye.


Terry

Terry I think this is the piece you recall? I posted in the AMOC Slowdown thread back in January because I didn't know where else to put it.   

http://www.cbc.ca/news/canada/nova-scotia/water-waters-climate-change-dfo-oceans-fisheries-science-1.3922876

[TerryM]

Terry I think this is the piece you recall? I posted in the AMOC Slowdown thread back in January because I didn't know where else to put it.   

http://www.cbc.ca/news/canada/nova-scotia/water-waters-climate-change-dfo-oceans-fisheries-science-1.3922876

That is the post I was remembering.
Thanks so much.


The 11 c deep water temperature caught my eye & the fact that this water seems to be moving up onto the shelf seemed ominous.
Has there been any additional information locally about this occurrence?
I worried about the effect on commercial fishing, as well as the implication for shelves further north.


Thanks again
Terry

[Cate]

Terry wrote: "Has there been any additional information locally about this occurrence?
I worried about the effect on commercial fishing, as well as the implication for shelves further north."

Terry, perhaps you heard about the new snow crab stock numbers, reported on CBC a few days ago? Link below. Snow crab stocks off the coast of NL are down 80% since 2013. The cause is acknowledged as warming waters over the past "decade or more."

It is encouraging at least to see our professional fisheries scientists flagging up climate change, even if you have to read the fine print to get it. CBC is certainly not going to highlight the fact in a headline!

This comes on the heels of a similar announcement of decline in shrimp stocks. These two species are significant "cash cows" for fishermen and fishing communities in Atlantic Canada, and declines mean nothing but bad news for the economies of the Atlantic provinces, with cod stocks still on the ropes.

http://www.cbc.ca/news/canada/newfoundland-labrador/snow-crab-stock-assessment-1.4001411

[DrTskoul]

A world of hurt....

[TerryM]

Thanks Cate
I very seldom read the news anymore & both articles you posted had slid by unread.
I spent a month in Newfoundland & Labrador in 2005 and was fascinated. A friend was digging at Ferryland and showed me some points from close by Port au Choix that, much further south, would have been identified as Clovis.
The Rock has been inhabited for a very long time.


It seems to me as though 11c bottom water on the shelves could present opportunities for clathrates to disgorge CH4 in worrying  amounts, as well as the end of the crab fisheries. The offshore oil platforms assure us of methane's presence in the region & a bump in bottom temperature might be all it takes for a major release.


Thanks again
Terry

[Cate]

Terry, you might be interested in reading up on the Burin tidal wave of 1929, on the south coast of Newfoundland. There is some thought now that this may have been triggered by an undersea landslide on the continental shelf off Nova Scotia, a similar event--although on a much smaller scale!---to the catastrophic Storegga slide that drowned Doggerland, filled the North Sea, and made Great Britain an island a few years ago.

There is currently a multi-uni, multi-disciplinary study going on out of the UK, looking at the possibilities of undersea landslips around the North Atlantic basin and their possible effects on UK sea-level and how that might be mitigated, etc. One of the focal points of the study is the effect of climate change on clathrates, which apparently can cause landslips as they disgorge. I'll see if I can dig up the links. 

[Cate]

Terry, copying this from a post I made in Earthquakes and Climate Change thread last year:

"Will climate change in the Arctic increase the landslide-tsunami risk to the UK?"

This is a major multi-year collaborative study focusing on the possibility of Storegga-type landslides happening as a result of Arctic warming. My interest in this is personal, as Newfoundland is also included in the study area. We know about landslip tsunamis in this corner of the Atlantic: in 1929, the south coast of Newfoundland suffered a tidal wave associated with an earthquake-landslip on the continental shelf. The 1929 event may or may not have been linked to climate change, of course, but it is very interesting to see that scientists are interested in finding out what the effects of climate change might be for the ocean floor up north.

http://projects.noc.ac.uk/landslide-tsunami/

This BBC article sets out the issue in layperson's terms.
http://www.bbc.com/earth/story/20160323-the-terrifying-tsunami-that-devastated-britain?ocid=global_earth_rss

[TerryM]

Cate


Sorry for the delay in replying.


I read up on the Storegga event some years back and had concluded, unlike most experts at that time, that it was due to clathrate breakup. The Bunin tidal wave is new to me, but it sounds as though methane could again have been the cause.


When I was at L'anse aux Meadows, the docent pointed out that the Viking harbor had risen ~5 meters, and that much of the low field we were viewing would have been been sea bottom a thousand years earlier. Assuming that the continental shelf has rebounded along with the island, it's reasonable to assume that any buried clathrates now have less pressure keeping them together.


When coupled with the recent increase in shelf water temperature this could lead to an explosive combination. 
 
I wonder if any of the shelves have the "pingo like" features that mark the floor of Hudson Bay? I'd expect strong currents would have obliterated most traces, but if we're worrying about near future events, then near past events might still be distinguishable.


If "pingo like" features are visible on the surface of the shelf, the likelihood of a shelf collapse would seem to increase. If none are to be found it might relieve some anxiety.


Stay safe
Terry

[Cate]

LOL Terry I'm too old to lose any sleep over this stuff.

Apparently there are submarine pingos all over the Beaufort as well. Incidentally, I found this on an old forum discussion about an ice-free Arctic:

"In 1980 the CCGS John A MacDonald struck the top of an uncharted undersea mound off of Eureka. The heavy icebreaker was creased and holed." Possibly a pingo? I suppose they wouldn't pose much of a hazard to shipping with modern navigational equipment. Unless one went kaboom just as the ship was passing over it. 

For interest, here is a short paper on tsunamis in Atlantic Canada. 
https://maritimemuseum.novascotia.ca/research/atlantic-tsunamis