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Discussion: Nice Post!

in: bhall; bhall > 2024-02-07

Feb 8, 2024 11:51 AM # 
khall:
As always! A really interesting read.
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Feb 9, 2024 7:37 PM # 
iansmith:
This is another example of an excellent post:

Feb 9, 2024 7:48 PM # 
iansmith:
Quite a fascinating read, though. Is there a map of locations of ice coring, say with associated publications? I had never heard of shallow ice coring to study decade-time scale ice before.
Feb 10, 2024 5:18 AM # 
Danny Riley:
Yeah, I've never heard of shallow ice coring studies for decade-time scale ice before either.
Feb 12, 2024 1:15 AM # 
bhall:
A great question!

So there are three general types of cores: hand auger, shallow, and deep cores.
Hand auger cores are done, well, with a hand auger...they are typically somewhere between 20-30m (sometimes as far as 40m) and they are really just looking at the snow and firn layers (though that depends on the location of the drilling, and the time that covers also is location dependent). For the
~40m to ~200m is considered "shallow drilling" which, again, depending on location will cover different amounts of time, but can cover a few hundred years.
Deep cores are ~200m and deeper, but really the cut off is where the drill requires drilling fluid to keep the borehole from freezing up (hence the rough border depth- it is very location/temperature dependent). These are mostly in Antarctica and Greenland, and they are the ones getting down to 3,000+m and covering up to 800,000 years.

As for a map of locations of shallow cores, this is a map of some of the Pacific Northwest shallow cores done on alpine glaciers. I'll work on finding some papers for you as well, though some of them do not have publications yet.
Feb 13, 2024 6:48 PM # 
iansmith:
Interesting. A bit of a naive question - how consistent are the shallow cores from different locations? (Citations welcome but unnecessary; I know you have actual stuff to do.)
Feb 17, 2024 10:13 PM # 
bhall:
Do you mean how consistent in terms of what they are showing for past climate records?

Here are some papers for your perusal (I will admit I have not read all of them through completely yet, though they are in my file for future reads):
Ice-core net snow accumulation and seasonal snow chemistry at a temperate-glacier site: Mount Waddington, southwest British Columbia, Canada (the original Waddington paper)
Mount Logan ice core record of tropical and solar influences on Aleutian Low variability:500–1998 A.D. which is the older Logan core (one was done more recently, there is a blog post here written by Allison Criscitiello about the newer one)
Ice Cores from the St. Elias Mountains, Yukon, Canada: Their Significance for
Climate, Atmospheric Composition and Volcanism in the North Pacific Region
which is a bit of a conglomeration of a bunch of the cores
Feb 19, 2024 9:07 PM # 
iansmith:
Thx.

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