Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Tor Bejnar

Pages: [1] 2 3 ... 54
"She", the large floe within the Lincoln Sea for which there is a poll, has a curious texture.  Note scale in lower right corner.  Blue, I understand, is melt ponding and pink is 'white' ice.  Any takers on what the pink lines (typically 50-60 m wide) represent?  (The image shows just part of the floe; its edge shows in the lower and lower right corner of the image.) Sentinel-hub Playground image.

Antarctica / Re: Antarctic Icebergs
« on: June 26, 2019, 09:36:06 PM »
A68-A is amazingly close to Robertson Island.  From the last published image just above, the ice island has rotated a little (counterclockwise as always) and snuggled up close to the island.  At the surface, the ice island is about 300 meters from the thin white line that approximates the edge of the island.  (yellow lines approximate the gap) PolarView image from today

Policy and solutions / Re: Nuclear Power
« on: June 26, 2019, 08:42:29 PM »
I will accept that 'time' is not the only potential solution to the nuclear challenge.  It is true that we poison many environments knowingly and unknowingly with many substances, natural and 'man-made'.  We're pretty good at, what's the phrase, "Why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye?"

Policy and solutions / Re: Nuclear Power
« on: June 26, 2019, 07:45:30 PM »
The problem with high radiative nuclear waste is that there is no solution.
Geologic time solves lots of problems.  Astronomic time solves even more. 

Yeah, I might have been trained as a geologist, but I get impatient with the idea we have to trust ten or fifteen thousand generations to not abuse some waste created for the benefit of a few generations (me included). 
Plutonium half-life:  24,100 years
Safe after: 10 to 20 half-lives
1 generation: 30 years
24,100 x 15 ÷ 30 = 12,050 generations
[references: Live Science and ISOGG]
Yes, maybe thirty years from now we'll discover a cool use for radioactive waste - but it's always (so far) 'maybe in 30 years'. 

When's the last time there was a continuously stable civilization lasting even 100 generations?  None, apparently:
Rome: 50 generations
Kush: 47 generations
Venice: 37 generations
[reference: HowStuffWorks]
Using a 20-year generation span (but see ISOGG reference), Rome could claim 75 generations.

And the radioactive waste is spread around the world, so we'd need multiple stable civilizations … Do you think global warming might disrupt any of the existing waste-securing regimes?

All of this functionally guarantees there will be abuse, some serious, of nuclear waste during the next thousand plus years.

The rest / Re: Pareidolia
« on: June 26, 2019, 05:54:08 PM »
a huge LOL! :'(

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 26, 2019, 05:49:23 PM »
I asked someplace if grid size was adequate for discerning area, etc.  A-Team was kind enough to have a look at the question and came up with a clear "No."  His review included AMSR2.  Review his work at the link.  He recommends "decide how you would classify individual grid cells" as to their extent or area.  My sense is there is a great deal of ambiguity where it matters (dispersed very small floes).
TorB asks: are ground resolutions of satellite images adequate for computing accurate extent, area, concentration, and volume in summer, given floes floating in open water/slush?
No. The grid cells are far too big in some forum products relative to the size distribution of floes in summer. Error soars as grid cells begin to depart from the intrinsic scale provided by floe sizes.
It is true that comparing this year's data (or calculations) with previous year's data using a single metric (NSIDC or AMSR2, etc.) is useful.  One question most of us don't ask is "What would the best metric be, given the data that has been available for several years?"  Occasionally, the gifted among us use pixel counts of things on a map presentation.  Would that give us 'better' numbers?

The rest / Re: Pareidolia
« on: June 26, 2019, 04:21:14 PM »
(my wife's 21 year old cat, which I call an elephant, but I think you don't want to here that story).
Ehrm, you've made me curious Tor  :)
OK:  I grew up a 'dog person', partly because the several cats we had all died young.  So when my wife and kids got Houdi (after Houdini because, as a kitten, he would climb the textured wall paper to the ceiling), I was excused from caring for him because "I hate cats" (or so I said - you know, it's a political thing).  Well, the kids grew up and left home (all in their 30's now - I should be grateful).  My wife regularly 'teases' me by asking if I love Houdi, so I have come to reply, "Yes I do, because he is an elephant."  Houdi is grey in color, so why not? And I do 'love' elephants (I even receive an "elephants - 'good news'" weekly Google e-mail).  With the special needs of an older cat, I do a fair amount of care for him (the 3 kids in town don't come around on a twice-daily basis to do what they promised 21 years ago - sigh … kids these days!), but that's okay because I love elephants (and my wife).

Permafrost / Re: Arctic Methane Release
« on: June 26, 2019, 02:42:51 AM »
Thanks, Ken.

Arctic sea ice / Re: The 2019 melting season
« on: June 26, 2019, 02:22:58 AM »
Welcome, Steerpike!
As some have said, the first post is the hardest.

one autumn soon, the ice will break up and a lot of it flushed out of Fram/Barents.
I sometimes forget how big the Arctic Ocean is.  (It, after all, fits on my computer screen, right? :o )  A-Team occasionally posts movies that trace identifiable features through a season or two (e.g., here - 3rd movie).  At 'real life' rates, it would take several months to move ice from the North Pole to a graveyard sea in a good-for-export year (as last 6 months have been).  Even those of us who are 'slow' would see the possibilities.  (We never know if it is a good-for-export year until we're most of the way through it.)
A-Team wrote in that linked May post:
Normally [the ice] just sits there but over the last 172 days a great unprecedented swath of ice has steadily moved from islands off central Siberia across the pole nearly to and out the Fram.
And a BOE is not likely this year.  [In 2013 I predicted 'ice-free Arctic' in 2019 ..., so I'm not declaring this outcome definitively, yet!  ::) :P )

Permafrost / Re: Arctic Methane Release
« on: June 26, 2019, 12:56:02 AM »
And I'm sure that you'll recall that while the average depth of the ESAS is 10m, 50% of the area of the ESAS is more than 50m deep.
I'm confused:  If 50% of an area is 50 m deep and the other 50% is 0.0 m deep, the average will be 25 m deep.  So how can the two halves of what I quoted be true?

To add to the discussion (maybe), I recall reading some permafrost is melting some 70 years before it was expected to (by some scientists).  I expect some things, like methane release from various natural environments, will be faster than 'expected'.  Bomb?  Hope not; but I'll let actual experts tease out the truth.  There will be lots of different types of truths revealed!

Wouldn't it be 'just hilarious' if She hung around Lincoln Sea all NH summer and autumn and then blocks Nares next December.

Maybe "She will not be able to block the strait of Nares" meant She couldn't because She never got there.

The rest / Re: Pareidolia
« on: June 25, 2019, 04:03:03 PM »
Fortunately for me, with the rarest of exceptions, the faces I see every day are attached to my friends, neighbors, coworkers, family and Houdi (my wife's 21 year old cat, which I call an elephant, but I think you don't want to here that story).

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: June 25, 2019, 03:55:31 PM »
On the melting thread, a comment was posted that some might interpret as implying there has been continuous export.  Cross posted here:
steady Fram and Nares export
Actually, export via Nares Strait has been near 'squat' for two weeks.  Images from DMI Sentinel - June 15, 19 and 24.  There is a poll about the large floe "She" that sits at the top of these three frames (half cut off).
I make no comment about what export will look like this week or beyond.

Arctic sea ice / Re: The 2019 melting season
« on: June 25, 2019, 03:48:40 PM »
steady Fram and Nares export
Actually, export via Nares Strait has been near 'squat' for two weeks.  Images from DMI Sentinel - June 15, 19 and 24.  There is a poll about the large floe "She" that sits at the top of these three frames (half cut off).

Developers Corner / Re: Test space
« on: June 25, 2019, 02:12:48 PM »
To further B_'s question, can you say more about
the main issue being the abrupt spring to summer transition in contrast from age-related features to exposed leads, which happened on June 4th (day 155) this year.

Policy and solutions / Re: Carbon Capture and Storage (CCS)
« on: June 24, 2019, 06:35:09 PM »
I don't recall there being an "off the grid - personal utility company" thread, but references to individuals doing that are scattered here and there. 

Ah, I found Off-Grid Is it really a contribution to the solution that was active in March 2013 (with a dozen posts).  Do you want to move "Off Grid" posts there?

Policy and solutions / Re: Renewable Energy
« on: June 24, 2019, 12:03:46 AM »
Boy am I glad I removed the offending sentence before (long before) Bob posted his 'correction'!  Not fast enough, obviously!  (I did read an article on how cats are worse than coal (or anything else) in killing birds.)

Developers Corner / Re: Test space
« on: June 23, 2019, 11:58:34 PM »
A-Team has posted GIFs (or MP4s) that show moving features over the course of a period of time, sort of like the 3rd image from here.  I find this the most useful manipulation to help my understanding what has been happening, for example, that ESS ice does not get exported to the Atlantic in one year in the 'best' of times, ever.

As a 'short cut', would there be a way of using the automated arrows (concept) to display automated curves (not too many, though) that jerk around, distort, and (often) migrate across the Arctic?

Policy and solutions / Re: Carbon Capture and Storage (CCS)
« on: June 23, 2019, 11:32:59 PM »
Crandles deserves more "likes" then he gets.

What's the topic, anyway???  Oh yes, CCS.  For my kids' sake, cannot we have an 'everything and' policy?  buried wood, cactus farms, maphic rock crushing, exhaust chimney capture, etc.  When 'we' get CO2 below 400 or 375, then get picky (and phase out the least efficient or most centralized systems).  There's a war out there!  (and no one is noticing)

Policy and solutions / Re: Renewable Energy
« on: June 23, 2019, 11:13:33 PM »
Crescent Dunes Solar Energy Project has some data in Wikipedia. 

Edit: removed chart etc.

Policy and solutions / Re: Tesla glory/failure
« on: June 23, 2019, 10:58:02 PM »
Your comment inspired the thought that one of Tesla's goals is to 'replace' the $20,000 car with a $35,000 car that will last four times as long (and therefore save people money, and give more value).

For example, my parents, in 1947, bought a house in Michigan for $1,000 (with electricity but without running water - yes, an outhouse out back - sold a year later with some improvements for twice that).  I believe it (with many others) was built a few years earlier for married student housing 'for the war effort'.  I cannot imagine a house (with an occupancy permit) today in the $10,000 - $25,000 range (the equivalent, per here) (without being a 'tiny house').  "Modern" standards require many more features, and people just 'budget' for the higher base price 'without thinking'.

We used to need Baffin Bay to melt the ice exported through Nares Strait.  "They" decided to cut out the middleman and are now melting that ice in the Lincoln Sea.  What will Nares do for a living now?  Talk about being in dire straits! :o ::) :P

Arctic sea ice / Re: The 2019 melting season
« on: June 23, 2019, 09:51:48 PM »
The Russians, just like the Iranians, don't care for other's drones flying over "their" territory.  The article I read on the Polarstern mentioned the special permits (with the implied "hard to get") required to acquire data from Russian seas.

Policy and solutions / Re: Tesla glory/failure
« on: June 23, 2019, 06:44:10 AM »
Glad to be corrected about delivery number release timing.

Policy and solutions / Re: Tesla glory/failure
« on: June 23, 2019, 06:08:23 AM »
We should know soon.
  I recall they report over a month after the end of the quarter.  To teach us patience, I think.  :o ::) :P

The rest / Re: Good music
« on: June 22, 2019, 02:37:48 PM »
Thanks, B_,
I got the "ice bear" part all by myself! (the pictures helped)

The rest / Re: Good music
« on: June 22, 2019, 02:21:18 PM »
That was cheery, kassy!  :'(

The rest / Re: Good music
« on: June 22, 2019, 05:07:19 AM »
When I click on your Margaret Whiting song link, I got a "Video not available" response, so I copied her name and the song title and did an internet search, opened the Youtube link and listened. 
Thanks, too, for the Rod Stewart song.  I don't recall ever hearing either.

Policy and solutions / Re: Tesla glory/failure
« on: June 22, 2019, 04:55:19 AM »
Thanks, Neil, for trying to explain.  I know I understand some of what you wrote (and I agree with you) and I think I understand most of it  :) :o  Virtually all of my finance background is with not-for-profit organizations that didn't/don't sell material products, so my understanding on some things is rather vague.  Part of my vague understanding tells me that a warehouse full of paid-for things that will go into future cars will affect cash flow (and balance sheet) but not the P/L statement.  Once in a sold car, both the costs and revenue will be part of the P/L.  I do not have a clue on how a company handles the value of intellectual property that enhances the stuff in the warehouse.  Is this what you're saying gets expensed up front, causing Q1 to have a loss and Q2 a chance for real profit?

Arctic sea ice / Re: SMOS
« on: June 22, 2019, 12:24:40 AM »
I don't recall ever seeing the term "flaw polynya" before, and it took some searching to find a definition, finally (from here):
flaw polynyas (band-like ice-free areas), which form
simultaneously with land-fast ice in November. Flaw polynyas
reach tens of kilometres in width and migrate out of fast ice
hundreds of kilometres northward (Smolyanitsky et al., 2003),
and here
A polynya is defined as any nonlinear-shaped area of open water and/or sea ice cover < 30 cm thick enclosed by a much thicker ice cover (WMO 1970). It can be restricted on one side by a coast, terrned shore polynyas, or bounded by fast ice, termed flaw polynyas.

Policy and solutions / Re: Tesla glory/failure
« on: June 21, 2019, 08:33:37 PM »
concerning 'new' computers:
it's likely that Tesla started with at least 2Q of orders.  All to be paid in Q1 2019.  It is also likely that the rest of 2019 will be invoiced and paid in Q2.
If a part (e.g., computer) is going into a car, it doesn't matter when that part was ordered, delivered, put into a car or paid for.  If the car has not been delivered, the cost of the item is in the balance sheet, not the profit/loss (P/L) statement.  All the costs of the components of the car go into the P/L statement at the time of delivery, regardless of whether it was paid for yet or not.

I know Crandles had written this before...

Arctic sea ice / Re: The 2019 melting season
« on: June 21, 2019, 06:56:26 PM »
Could someone plop a grid (actually grids) on top of a satellite image (such as posted by jdallen just above) so we can see examples of what the different Extent-data-sources (JAXA, NSIDC) are dealing with.  For example, what does the 3.5 km (or whatever) grid look like over actual ice.

Arctic sea ice / Re: "Stupid" Questions :o
« on: June 21, 2019, 06:10:30 PM »
Also on the ASIB - Arctic Maps thread  -  scroll down to the NSIDC identified map (the 5th map in that post).  Gives link to interactive NSIDC map as given by Gerontocrat while I was typing.

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: June 21, 2019, 06:07:10 PM »
Yes, Baffin Bay volume data is puzzling.

Arctic sea ice / Re: SMOS
« on: June 21, 2019, 04:51:28 PM »
I know little about SMOS, but their sensors do detect "salinity".  So conceptually, it would register surface melt differently from a salt water wash.  However, SMOS reports on a 35 or 40 km grid (I've read both; I presume it is one or the other, unless it is latitude dependent), so the sensors-to-data-output-system is doing a great deal of averaging.  As open water is very wet, as soon as SMOS looks at floes that are 'small' (and not perfectly packed together), it starts averaging (convoluting) thickness with wetness and the thickness output becomes seriously/totally irrelevant (per SMOS literature).  As Oren suggested, a salt water wash will occur mostly along the edges of floes, so the salinity SMOS detects from open water might be very slightly exacerbated by salty water on a floe.  I conclude with Oren, "negligible", and add "irrelevant after review."

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: June 21, 2019, 03:43:06 PM »
the volume in the 2000s barely reduces for weeks around the minimum, while area continues shrinking.
Just as CAB ice continues to thicken long after 'fringe' sea ice melts out (causing volume max to follow [and not follow closely] area/extent max), CAB ice will start thickening before the remaining pack stops melting at the edges.  The North Pole summer is shorter than the 80ºN summer - it starts later and ends sooner. 

Therefore, as 'fringe' volume (and total area) continued to decrease in September in the 2000s, North Pole volume started increasing. 

Today, I suspect (=deduce without looking at hard numbers = guess) the NP freezing season starts much later than it used to, while its melting season starts shortly before the time it used to.

Arctic background / Re: Research Icebreaker Polarstern
« on: June 21, 2019, 01:17:51 AM »
I'm embarrassed that I didn't read with comprehension that "335 miles" sentence when I selected it for posting. :-[   My guess: "335 miles south of the pole along longitude 90˚E".  We will probably find out in September.

Policy and solutions / Re: Oil and Gas Issues
« on: June 20, 2019, 09:31:05 PM »
I basically agree, Archimid.  Unfortunately, part of the mix includes Mr. Putin wanting a weakened USA and more money from petroleum exports.

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: June 20, 2019, 09:19:36 PM »
Export from Lincoln Sea to Nares Strait has started up again.  GIF uses DMI Sentinel images from June 17, 19 and 20.

Viewing images at the DMI site down Nares Strait: Hall Basin got the memo and is filling up with ice from the north, but Kane Basin has a gyre recycling its few floes (for now).

Arctic background / Re: Research Icebreaker Polarstern
« on: June 20, 2019, 08:36:18 PM »
For the biggest Arctic expedition ever, scientists will trap themselves in sea ice

Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) will begin on Sept. 20 - when the icebreaker RV Polarstern sets out in search of an ice floe to which it can pin its fate.

The ship will spend the next 12 months following that single floe through the central Arctic and across the North Pole - a 387-foot drifting research station inhabited by a rotating cast of some 300 meteorologists, biologists, oceanographers and ice experts.

About 60 people will be living and working on the Polarstern at any given moment; most have signed up for two-month stints, though a few may be onboard for half the year or more. Virtually their only link to the rest of the world will be the ships and aircraft scheduled to arrive every 60 days - winter blizzards and stormy seas permitting - to switch out passengers and restock food and fuel.

Simply getting to the Polarstern can take as long as a month; participants joke that it's easier to reach the International Space Station, 250 miles above the surface of the Earth.

But the drift strategy has perils. Choose the wrong ice floe, and the scientists could end up in Russian waters, where outsiders can't collect data without special permits. Or the ice could carry them far to the west, beyond the reach of rescue missions should anything go awry.

Analyses of ice paths from previous years suggest that the ideal floe lies about 335 miles east of the North Pole. By the end of a year, it should deliver the Polarstern to open water somewhere between Greenland and the Svalbard archipelago.

A successful transpolar drift - one that didn’t kill nearly everyone onboard - has been achieved just twice before in history: first by the Norwegian explorer Fridtjof Nansen, in 1893, and a decade ago by the small crew of a privately owned sailing ship called the Tara. The Polarstern will be the first modern research vessel to spend an entire year at the northernmost place on the planet.
and much more …

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: June 20, 2019, 07:51:26 PM »
Also, melt ponding went from nil to very much happening.

Consequences / Re: Heatwaves
« on: June 20, 2019, 06:57:08 PM »
Yes, thanks for that story.  Matt Rutherford, when crossing the Equator going south in the Pacific (as I recall) used a bunch of his diesel to get through the doldrums (or near them), and his goal was Maryland (via Cape Horn).  [See his November 26, 2011 (heading south) and January 10, 2012 (going north) posts, + and -.]  He made it all the way around the Americas, by the way!

Am I seeing slap-happy 'drunkenness' (here and "Stupid Questions" and "Meaningless") because we are scared out of our wits with what we think we're seeing in the Arctic?

The rest / Re: Peak Oil and Climate Change
« on: June 20, 2019, 06:05:18 PM »
Oil sands are being mined, for sure :'( , but some think oil sands will be the major source of hydrocarbons for industry in the future.  :'( :'(

Canadian Association of Petroleum Producers
Canada has the third-largest oil reserves in the world. Of the 170 billion barrels of Canadian oil that can be recovered economically with today's technology, 164 billion barrels are located in the oil sands. The IEA says Canada is expected to be third in oil production growth over the forecast period, after Brazil and Iraq.

With consumption rising worldwide and conventional oil supplies declining, the need for a secure supply of oil from unconventional resources like Canada’s oil sands will continue to increase. With the majority of reserves located in the oil sands, the resource has potential to become a key global supplier. As the IEA reports, Canada has the energy the world needs – our challenge is to move it to new customers in new markets in the years ahead.
[Where's the "I'm sick" icon?]

An Overview of Alaskan’s Prehistoric Cultures
June 15, 2018 - Alaska Department of Natural Resources
The oldest confirmed prehistoric sites in Alaska belong to the Eastern Beringian Tradition, dating from about 14,000 to 12,000 years ago. They were occupied while Beringia was still isolated from the rest of North America and connected to Eurasia. The earliest sites in this tradition contain stone tools that closely resemble technology found in many Upper Paleolithic sites in Northeast Asia, and may represent some of the first migrants from the Old World into North America. Most of these earliest Beringian sites have been found in the Tanana River basin of Interior Alaska and date to a time of late glacial climatic warming called the Allerød interval. In tandem with the ameliorating climate, shrub tundra and possibly a few trees began to appear across much of Beringia during the Allerød. The addition of wood to the resource base may have been critical to the early migrants as a source of fuel and materials for tools and shelters.
(from page 7 of 54 pages of text and pictures)

Archaeology at Raven Bluff, Northwestern Alaska - Frontier Scientists - Posted on February 2, 2011
Archaeologists continue excavating a 12,000 year old prehistoric site overlooking the Kivalina River, yielding evidence of generations of wandering hunters. During the 2010 summer season, what they have found is contributing new insights– and contrary new evidence– into the thinking on how humans spread throughout North American at the close of the Pleistocene.
The Raven Bluff site was discovered in 2007 by BLM archaeologist Bill Hedman and a crew conducting an archaeological site survey in the far northwest corner of Alaska. The Bering Land Bridge between Russia and North America may have still existed–or had just submerged for the last time–when hunters first frequented Raven Bluff.
Jeff Rasic, archaeologist and curator for the University of Alaska Museum, guides the digging crew in finding some of the oldest preserved animal bone found anywhere in the America Arctic. Rapid soil accumulation, low acidity, and perennially frozen conditions resulted in excellent bone preservation.
The notion that people at this time period were bison hunters in Northern Alaska is being put to the test; 12,000 years ago, what is now moist tundra was a drier, grassier landscape grazed by animals that included bison.
Another established scientific hypothesis being tested is how the use of certain stone tools spread in North America. The lower levels of the site produced a very significant find of a roughly 12,000 year-old fluted projectile point base, marking the first time such a tool has been definitely dated in the north. “The idea for decades has been that fluted projectile point technology originated in Alaska or perhaps Siberia and was carried south into the Americas,” explains Rasic. This model suggests that the Raven Bluff tool should be older than similar points found further south on the continent. , so it may be that they did not originate in the north, but came from the south. So the question now is, does this represent a migration of people, or the spread of an idea from the south?”

Fluted projectile points in a stratified context at the Raven Bluff site document a late arrival of Paleoindian technology in northwest Alaska -  Buvit, et al. -  Geoarchaeology · September 2018 
Our understanding of the northern fluted point tradition, a critical early New World lithic assemblage, is constrained by limited data from stratified, datable contexts. Here, we report on the Raven Bluff site in northwest Alaska, where fluted projectile points, microblades, and a well‐preserved faunal assemblage have been recovered from datable sediments. Results show that prehistoric inhabitants occupied a stone‐sorted polygon where retooling, game processing, and raw material procurement occurred mostly between 12,720 and at least 11,340 cal. yr B.P. We argue that once polygon formation ended, the stratigraphic context remained relatively intact. Further studies focused on the site’s lithic and bone assemblages will help shape our understanding of the relationship between fluted point technology, microblades, and caribou hunting in northern Alaska.

Artic Meltdown: We're Already Feeling the Consequences of Thawing Permafrost - Discover Magazine - January 2019
… researchers from the Russian Academy of Sciences sprouted three dozen Silene stenophylla, herby white tundra flowers, from 30,000-year-old fruits. The specimens were recovered from ancient squirrel burrows, 125 feet deep in the permafrost of northeast Russia, according to the study published in Proceedings of the National Academy of Sciences. After sprouting in nutrient-rich test tubes, the seedlings had run-of-the-mill plant lives: They grew into fruit-bearing flowers in plastic pots and soil, resuming normal biological activity after being frozen for 300 centuries.
Finally, something "prehistoric"! 

… at Birnirk, a site in far north Alaska dated to A.D. 600-1300, archaeologists recovered parkas, boots and even baby clothes made from sealskins and polar bear fur — “incredibly high-performing garments out of all natural materials,” says Rasic. “They made fine needles and threads and could sew watertight seams in a time before Gore-Tex and all the high-tech fibers we have now.”

At another Alaskan site, Raven Bluff, bones were so well preserved that Rasic assumed they were a few hundred years old. But results from radiocarbon dating brought a shock: Raven Bluff was inhabited 11,000 years ago. Permafrost sites of this era are key to understanding how Ice Age people migrated from Siberia and settled the Americas.

The Emergence of Glacial Archaeology - doi: 10.1558/jga.v1i1.1  Journal of Glacial Archaeology - 2014

Good introduction to history of Glacial Archaeology and a description of ice types (valley glacier, ice sheet, ice patch).

Melting Yukon ices reveals 5,000-year-old archaeological treasures - June 2014
According to Hare, climate conditions on about two dozen Yukon mountains have proven to be almost uniquely suited to preserving organic material. Unlike glaciers that move, slowly grinding down any artifacts trapped in them, the Yukon ice patches tend to remain stable. Or at least they did, until gradual warming over the past several decades began to shrink them and reveal treasures. Among the finds: wooden darts as old as nearly 9,000 years, some complete with stone points, sinew bindings, bits of feather and traces of ochre decoration; a finely carved, barbed antler projectile point from about 1,200 years ago; and a size-four moccasin, 1,400 years old, amazingly intact, and believed to be a boy’s. “Some of it is very beautiful,”

IRON AGE HORSE // NORWAY - website: Mental Floss - August 2017

In September 2013, bones from an Iron Age horse were uncovered from a site over 6500 feet high in the mountains of Norway. The horse, found alongside perfectly preserved manure and a horseshoe, indicates to archaeologists that Iron Age peoples were using these animals to carry cargo at high altitude over the mountains near Oppland in Norway. …  Earlier in 2013, an amazingly well-preserved 1700-year-old woollen tunic was also rescued from melting ice in the region—two patches on the garment showed that it had been carefully mended by its Iron Age owner.
OK, these aren't quite "prehistoric" …

Pages: [1] 2 3 ... 54