Support the Arctic Sea Ice Forum and Blog

Author Topic: What's new in Greenland?  (Read 132873 times)

oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #350 on: November 16, 2018, 06:25:56 PM »
The Wikipedia link Tor provided is very informative, and I found the criticism section quite useful.

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #351 on: December 01, 2018, 05:17:29 PM »
A map - of the position of the main Greenland glacier fronts. I can never remember them all (easily confused at my age).

Also posted on Arctic Maps
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #352 on: December 01, 2018, 08:11:29 PM »
Have you seen the Greenland map Espen once posted, with hundreds of named glaciers?

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #353 on: December 01, 2018, 08:13:26 PM »
Have you seen the Greenland map Espen once posted, with hundreds of named glaciers?
Nope - perhaps I will search for it. Too many glaciers!
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #354 on: December 01, 2018, 09:04:39 PM »
Actually I just recalled it's in the sticky thread in this very sub-forum. "Google Maps with place names Greenland." It was started by Espen, but the map was posted by A-Team a bit down the thread.

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #355 on: December 01, 2018, 10:03:14 PM »
Actually I just recalled it's in the sticky thread in this very sub-forum. "Google Maps with place names Greenland." It was started by Espen, but the map was posted by A-Team a bit down the thread.
Found it. Almost impossible to read the names, but the really interesting thing is showing the velocity of movement that also shows up the catchment area of each glacier and where they merge into the main ice sheet..

What a big beast in the North East.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

litesong

  • ASIF Citizen
  • Posts: 374
    • View Profile
  • Liked: 20
  • Likes Given: 14
Re: What's new in Greenland?
« Reply #356 on: December 02, 2018, 04:38:27 AM »
Found it. Almost impossible to read the names
click on the map.... then select VIEW on the bar at the top of the screen.... pump the ZOOM UP. Makes the print a bit more readable.

sidd

  • ASIF Governor
  • Posts: 3858
    • View Profile
  • Liked: 70
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #357 on: December 05, 2018, 10:06:29 PM »
Very nice paper by Trusel et al. on the acceleration in GIS melt beginning at the start of the Industrial Revolution. I see that Fettweiss is an author.

"Our results show a pronounced 250% to 575% increase in melt intensity over the last 20 years, relative to a pre-industrial baseline period (eighteenth century) ..."

"rates of meltwater production, refreezing and runoff across much of Greenland are all at multi-century highs ...

"The onset of industrial-era Arctic warming occurred in the mid-nineteenth century [21] and differential smoothing analysis likewise indicates increases in GrIS runoff initiated shortly thereafter (Fig. 4b; Methods). The median onset of positive trends in GrIS runoff are also coincident with the median onset of weakening Atlantic meridional overturning circulation [9] . Emergence of runoff beyond the natural range of variability, however, has only very recently occurred ..."

"Today, surface melting and melt-induced runoff in Greenland occur at magnitudes not previously experienced over at least the last several centuries, if not millennia."

I attach figs 4a,c. The latter illustrates the extreme nonlinearity of surface melt increase  with temperature. The thing is going to melt in place.

doi: 10.1038/s41586-018-0752-4

coverage at

https://phys.org/news/2018-12-greenland-ice-sheet-centuries.html

sidd

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #358 on: December 05, 2018, 10:53:42 PM »
Very nice paper by Trusel et al. on the acceleration in GIS melt beginning at the start of the Industrial Revolution. I see that Fettweiss is an author.

"Our results show a pronounced 250% to 575% increase in melt intensity over the last 20 years, relative to a pre-industrial baseline period (eighteenth century) ..."

"rates of meltwater production, refreezing and runoff across much of Greenland are all at multi-century highs ...

"The onset of industrial-era Arctic warming occurred in the mid-nineteenth century [21] and differential smoothing analysis likewise indicates increases in GrIS runoff initiated shortly thereafter (Fig. 4b; Methods). The median onset of positive trends in GrIS runoff are also coincident with the median onset of weakening Atlantic meridional overturning circulation [9] . Emergence of runoff beyond the natural range of variability, however, has only very recently occurred ..."

"Today, surface melting and melt-induced runoff in Greenland occur at magnitudes not previously experienced over at least the last several centuries, if not millennia."

sidd
There is a caveat. It is no surprise that summer melt is going up. But the melt happens in the brief Greenland Summer - June July & August. Surface Mass increases during the other 9 months - snow. The average net addition to mass in a year (Snow less melt - SMB) is about 400 GT. But calving exceeds this by about 200GT per annum

The prediction is for snow to increase at high latitudes due to increased water vapour due to AGW. In the last two years this has been the case. Quote from NSIDC's Greenland Today:-
Quote
The net change in (2018 mass of the ice sheet overall, including this higher discharge of ice directly into the ocean, is not clear at this point but may be a smaller loss or even a small gain. This is similar to our assessment for 2017, and in sharp contrast to the conditions for the preceding decade.

So melt in summer is just one of the three factors determining net loss of mass from the GIS.

When the new GRACE follow-on satellites starts to give us Greenland's mass change data again (hopefully from January 2019) we will know the extent to which the GIS is dumping ice into the sea.
links:-
http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/
https://nsidc.org/greenland-today/
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

bbr2314

  • ASIF Upper Class
  • Posts: 1231
    • View Profile
  • Liked: 70
  • Likes Given: 13
Re: What's new in Greenland?
« Reply #359 on: December 06, 2018, 01:26:08 AM »
It is interesting that the major spike in Greenland runoff was concurrent precisely with the collapse of the Soviet Union. This was presaged by a lull back below trendline as well. I would posit that the abundance of SO2 was responsible for this dramatic shift -- as local atmospheric concentrations rose during and after WWII, we saw runoff nearly come to a halt. But by 1980, as economic disruptions began worsening in the USSR, SO2 emissions began to plunge. While the US / others also emit SO2, perhaps Soviet emissions were more important to Greenland due to relative proximity (Greenland is technically downwind of Siberia in a stable three-cell scenario making its emissions more important for localized effect of SO2).

Clearly other things are at play (Beaufort Gyre release etc) but the sharp drawdown in USSR emissions coincides precisely with the massive spike in meltwater. Not only did economic activity fall during this period, but evidently "trapping" of emissions also began.


FredBear

  • ASIF Lurker
  • Posts: 93
    • View Profile
  • Liked: 4
  • Likes Given: 27
Re: What's new in Greenland?
« Reply #360 on: December 06, 2018, 10:56:07 AM »
BBR, SO2 from Russia hardly "plunged" from 1981-88, more like 10% reduction in the figures. Helpful but unlikely to stop acid rain?

Lurk

  • ASIF Citizen
  • Posts: 152
    • View Profile
  • Liked: 8
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #361 on: December 06, 2018, 11:53:51 AM »

"Large ice loss variability at Nioghalvfjerdsfjorden Glacier, Northeast-Greenland"
(Christoph Mayer et al.) July 2018
https://www.nature.com/articles/s41467-018-05180-x.pdf

Here's an older paper published in January 2018. May have some relevance overall, as they suggest similar conditions exist across Greenland not only in the NE. I hadn't heard of this Geothermal heat flux before in regards the speed of the GIS loss (apologies if this is old news.)

PR Article https://www.sciencedaily.com/releases/2018/01/180122091321.htm

Article in Full - High geothermal heat flux in close proximity to the Northeast Greenland Ice Stream
Søren Rysgaard, Jørgen Bendtsen, John Mortensen & Mikael K. Sejr

Scientific Reports volume 8, Article number: 1344 (2018)

https://www.nature.com/articles/s41598-018-19244-x

Cheers
American journalist Walter Lippmann observed, “Where all think alike, no one thinks very much!”

P-maker

  • ASIF Citizen
  • Posts: 193
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #362 on: December 06, 2018, 04:11:37 PM »
Lurk,
Why don't you check your sources. The original Nature paper says a geothermal heat flux of 93 mW per sq. m., whilst the popular version talks about 100 MW per sq. m. I know it may not seem important to you, but to some,  m&M may make a difference.

bbr2314

  • ASIF Upper Class
  • Posts: 1231
    • View Profile
  • Liked: 70
  • Likes Given: 13
Re: What's new in Greenland?
« Reply #363 on: December 06, 2018, 06:25:03 PM »
BBR, SO2 from Russia hardly "plunged" from 1981-88, more like 10% reduction in the figures. Helpful but unlikely to stop acid rain?
A much larger % was captured during this time as well. SO2, besides causing acid rain, reduces incoming solar insolation and temperatures. Maybe the global reduction was to blame? I know the US was also cleaning up during the 80s but would assume "clean-up" was more effective in USSR due to its economic meltdown (i.e., less SO2 emitting activity in general).

Lurk

  • ASIF Citizen
  • Posts: 152
    • View Profile
  • Liked: 8
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #364 on: December 07, 2018, 05:38:59 AM »
Lurk,
Why don't you check your sources. The original Nature paper says a geothermal heat flux of 93 mW per sq. m., whilst the popular version talks about 100 MW per sq. m. I know it may not seem important to you, but to some,  m&M may make a difference.

Why is that MY fault? I'm not the Editor at Science Daily.
« Last Edit: December 07, 2018, 10:24:25 AM by Neven »
American journalist Walter Lippmann observed, “Where all think alike, no one thinks very much!”

P-maker

  • ASIF Citizen
  • Posts: 193
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #365 on: December 07, 2018, 01:15:18 PM »
Lurk,

I guess my question really is: why pull out a couple of > 10 months old pieces of conflicting evidence in this thread?

I'm not blaiming anyone, just asking a simple question:

Are you being paid for sowing confusing seeds in the various Neven seedbeds?


oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #366 on: December 07, 2018, 01:28:29 PM »
Are you being paid for sowing confusing seeds in the various Neven seedbeds?
I am not known to agree with Lurk much but I protest the slanderous insinuation.

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 6078
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 241
  • Likes Given: 173
Re: What's new in Greenland?
« Reply #367 on: December 07, 2018, 01:57:01 PM »
I haven't followed this discussion. P-maker, how exactly is Lurk causing confusion, either intentional or unintentional?
Compare, compare, compare

P-maker

  • ASIF Citizen
  • Posts: 193
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #368 on: December 07, 2018, 02:33:23 PM »
Neven,
Lurk made a comment based on a solid German Nature-paper, which was published in July 2018. He then pulls in another Nature-paper from January, which is based on temperature observations made in another fjord located about 200 km N of the 79N glacier. In his post he makes  assumptions about variations in geothermal heatflux may be a contributing factor in the 79N glacier demise. Scale, cause, variability, distance and processes are completely out of whack. Call it intentional or not. I simply don't get it. Just to confuse things even more, he also deliberately pulls in an error-ridden popular version of the January paper. And then in his reply to me has the nerve to blame the editor of Science Daily for not catching an error made in the Press release from Aarhus University.
Cheers P

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 6078
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 241
  • Likes Given: 173
Re: What's new in Greenland?
« Reply #369 on: December 07, 2018, 04:57:58 PM »
Hmmm, sounds to me like you're being a bit too much on the alert.

Quote
In his post he makes  assumptions about variations in geothermal heatflux may be a contributing factor in the 79N glacier demise.

Yes, well, so do the authors of the Mayer et al. paper:

Quote
However, the reason for the large interannual fluctuations of
the thinning rates revealed by this study still need to be found

(...)

Thus, while our
analysis suggests that the ocean is likely the main driver of the
observed changes at 79 North Glacier, the regional dynamics that
control the heat transport into the ice shelf cavity and other
contributors, such as subglacial discharge induced by surface melt
or geothermal heat flux will need further attention to fully
understand the observed thickness evolution.

So, Lurk posts links to a paper on exactly that subject:

Quote
Hence, this part of Greenland may play a role for the rapid basal melt located at the head of the Northeastern Greenland ice stream and its high ice speeds. In addition, the newly discovered 52 hydrothermal vent complexes13, some of which reach up to 11 km in diameter, in the Danmarkshavn Basin and in the Thetis Basin is located just outside the ice-stream outlet glaciers; Nioghalvfjersbræ, Zachariæ Isstrøm and Storstrømmen (Fig. 5). These complexes are formed from hot intrusions (c. 1200 °C) at 1–2 km depth in the Thetis Basin and >3 km depth in the Danmarkshavn Basin. Hence, this accumulated evidence point to active geothermal activity in the northeastern corner of Greenland and indicate that geothermal heat source may exist below the center and northeastern part of GIS. This heat source may explain the origin of the Northeast Greenland ice stream and other areas with high ice stream speed.

Maybe it's me, but I don't see anything wrong with 'making assumptions about variations in geothermal heatflux may be a contributing factor in the 79N glacier demise'.

As for the m&M stuff: Lurk didn't even mention these numbers in his comment, and he's most certainly not responsible for mistakes made by the people writing the press releases, especially as he linked directly to the paper itself. Maybe he didn't even notice it (I wouldn't have).

Quote
And then in his reply to me has the nerve to blame the editor of Science Daily for not catching an error made in the Press release from Aarhus University.

But you have the nerve to blame Lurk for it.  ::)

Come on, this makes no sense. Don't be paranoid.
Compare, compare, compare

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #370 on: December 08, 2018, 08:46:38 PM »
Interesting paper on Greeland's tidewater glaciers suggesting a warmer ocean is going to accelerate calving by a lot.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080763
Localized Plumes Drive Front‐Wide Ocean Melting of A Greenlandic Tidewater Glacier
Quote
Abstract
Recent acceleration of Greenland's ocean‐terminating glaciers has substantially amplified the ice sheet's contribution to global sea level. Increased oceanic melting of these tidewater glaciers is widely cited as the likely trigger, and is thought to be highest within vigorous plumes driven by freshwater drainage from beneath glaciers. Yet melting of the larger part of calving fronts outside of plumes remains largely unstudied. Here we combine ocean observations collected within 100 m of a tidewater glacier with a numerical model to show that unlike previously assumed, plumes drive an energetic fjord‐wide circulation which enhances melting along the entire calving front. Compared to estimates of melting within plumes alone, this fjord‐wide circulation effectively doubles the glacier‐wide melt rate, and through shaping the calving front has a potential dynamic impact on calving. Our results suggest that melting driven by fjord‐scale circulation should be considered in process‐based projections of Greenland's sea level contribution.

Plain Language Summary
As the world warms, loss of ice from the Greenland Ice Sheet will be a significant source of sea level rise. Greenland loses ice partly through the flow of huge rivers of ice called tidewater glaciers that dump solid ice directly into the ocean. Over the past two decades, tidewater glaciers around Greenland have accelerated dramatically, increasing Greenland's contribution to global mean sea level. There is mounting evidence that these accelerations have been driven by ocean warming, and a resulting increase in the rate at which the ocean melts the front of tidewater glaciers (called submarine melting). Yet submarine melting is at present poorly understood, in part due to the danger and difficulty of collecting data close to tidewater glaciers. We present observations of the ocean in front of a tidewater glacier that are unprecedented in their proximity to the glacier. These data reveal an ocean circulation which flushes warm water along the front of the glacier, driving high rates of submarine melting. We then use a numerical model to identify what drives this circulation. Our results are an important step toward understanding a key process which will modulate future sea level contribution from the Greenland ice sheet.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

P-maker

  • ASIF Citizen
  • Posts: 193
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #371 on: December 08, 2018, 11:23:29 PM »
Neven,

I appreciate you take the time to read through the papers. In the Rysgaard et al thing they assumed the heating of the bottom of the fjord water could have been caused by a constant geothermal heat flux of 93 mW per sq. meter.

Lurk was using this number - remember we are talking milli Watts here - in an attempt to explain inter-annual variations in vertical thinning of the 79N glacier of up to 12 meter of solid ice in one single year.

Geothermal heat flux is for most practical purposes considered a constant, in particular if it comes from an Eocene intrusion som 55 mio. years ago. I do  acknowledge that hot spots under the ice may contribute to higher rates of bottom melt, but I would never have thought that this should ever be able to cause inter-annual variations in the mass loss from a floating ice shelf, which has lost about a third of its thickness over the past 20 years.

I could think of many other - more likely - factors affecting the inter-annual variation in ice loss from the 79 N glacier snout. Most likely - but also difficult to measure - is the advection of warmer waters from the Greenland Sea. Less likely, but it may still be found relevant, if measurements were available, would be inter-annual variability in sublimation rates. New evidence from Antarctica have in recent years addressed this issue in som detail, but I fear it will lead too far to go into more details here.

i will rest my case for the time being.

Lurk

  • ASIF Citizen
  • Posts: 152
    • View Profile
  • Liked: 8
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #372 on: December 09, 2018, 07:07:12 AM »
Quote
Lurk was using this number ...

Lurk wasn't using any number.

Lurk made no assertions about anything.

Lurk simply posted a new ref in a Thread called What's new in Greenland?

Lurk did say: "I hadn't heard of this Geothermal heat flux before in regards the speed of the GIS loss (apologies if this is old news.)"

Lurk, before posting the paper on a subject he had not heard of before in ~20 years of interest in the Arctic Ice Loss - skimmed back through the thread, to before Jan 2018, to see if someone had already posted it.

Lurk saw it seemed nobody had, but did notice the most recent post (August) looking at the same NE region of Greenland / Glacier flows (?) and so used that as a marker, a reference point, without even reading that paper.

Lurk then said: "May have some relevance overall, as they suggest similar conditions exist across Greenland not only in the NE."

Lurk meant by "overall" the entire GIS Flux - as in 'What's new in Greenland'. 

Lurk did that, and only that.

It's called sharing new information, Lurk had just found, for the benefit of everyone.  ::)

Next time, Lurk will think twice and probably keep it to myself. (sigh)
American journalist Walter Lippmann observed, “Where all think alike, no one thinks very much!”

oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #373 on: December 09, 2018, 11:17:08 AM »
Lurk is right, and the accusation very puzzling.

P-maker

  • ASIF Citizen
  • Posts: 193
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: What's new in Greenland?
« Reply #374 on: December 09, 2018, 12:05:34 PM »
Lurk & Oliven - you are quite a couple - the two of you!

By all means, carry on posting "news" like you have done in this particular thread, but please read the articles you intend to "flag" before you hit the keyboard. Self control is also about keeping the "noise level" down to the benefit of both yourselves and the remaining followers of this fine forum.

Have a nice Sunday!

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #375 on: December 09, 2018, 12:45:52 PM »
By all means, carry on posting "news" like you have done in this particular thread, but please read the articles you intend to "flag" before you hit the keyboard. Self control is also about keeping the "noise level" down to the benefit of both yourselves and the remaining followers of this fine forum.
I am sure we are all immensely grateful for your advice.

and that's all I am going to say about that
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

oren

  • ASIF Governor
  • Posts: 2969
    • View Profile
  • Liked: 317
  • Likes Given: 590
Re: What's new in Greenland?
« Reply #376 on: December 09, 2018, 12:47:48 PM »
P-Maker, sorry if it feels I have ganged on you - not intended. I have clashed with Lurk several times in the past when he bullied other posters. I could do no less when an unfair accusation was leveled at him.

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #377 on: December 09, 2018, 01:04:01 PM »
A suggestion that life on land may have started even earlier

https://gizmodo.com/remnants-of-earths-oldest-dirt-may-have-been-found-in-g-1830342281

Remnants of Earth's Oldest Dirt May Have Been Found in Greenland
Quote
Earth’s oldest soil could be tucked away in an ancient rock outcrop in Greenland, according to new research. Dating back some 3.7 billion years, the suspected soil—exposed underneath a retreating ice cap—could potentially contain fossilized traces of primordial life.

The new study, published this week in the awkwardly named science journal Palaeogeography, Palaeoclimatology, Palaeoecology, opens thusly: “Soil formation is a combination of physical, chemical, or biological processes important for regulating planetary atmospheres, and the ultimate source of essential nutrients such as phosphorus for the nutrition and origin of life.”

Indeed, soil—unlike sterile bits of rock or sand—serves as a natural medium for the growth of land plants. Identifying our planet’s oldest soils, therefore, is of critical importance to scientists who study Earth’s formative period and the emergence of our planet’s first organisms.

The new study, led by University of Oregon geologist Greg Retallack and Old Dominion University geologist Nora Noffke, describes a tantalizing new rock outcrop in the Isua Greenstone Belt of southwestern Greenland that, quite possibly, contains our planet’s oldest dirt, and by consequence, the oldest traces of life on the planet.

It’s not actually dirt—it’s a substance known as paleosol, former soil that’s been packed tightly into solid rock.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

litesong

  • ASIF Citizen
  • Posts: 374
    • View Profile
  • Liked: 20
  • Likes Given: 14
Re: What's new in Greenland?
« Reply #378 on: December 11, 2018, 09:07:42 PM »
Remnants of Earth's Oldest Dirt May Have Been Found in Greenland[/b]
Earth’s oldest soil could be tucked away in an ancient rock outcrop in Greenland.....It’s not actually dirt—it’s a substance known as paleosol, former soil that’s been packed tightly into solid rock.
Would this paleosol have any analog to sandstones?

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #379 on: December 11, 2018, 09:33:47 PM »
Something to look out for. It looks like the gap in GRACE data will be a lot less than I thought.

https://arctic.noaa.gov/Report-Card/Report-Card-2018/ArtMID/7878/ArticleID/781/Greenland-Ice-Sheet
Quote
Total Ice Mass Balance
GRACE satellite data can be used to estimate monthly changes in the total mass of the Greenland ice sheet, as done in the past (e.g., Tedesco et al., 2017). However, the NASA GRACE mission, which started in 2002, ended in October 2017. Hence, there are no data available on the total mass balance for the 2017/18 season. The GRACE Follow On (GRACE-FO, https://gracefo.jpl.nasa.gov/) mission was launched on 22 May 2018. Data acquired since its launch are currently under review for quality control. The May 2018 launch means that no data are available from space between October 2017 and May 2018. Processing of the GRACE-FO dataset will provide estimates of total mass change anomalies for the summer of 2018 and will be calibrated to data acquired by GRACE.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's OLD in Greenland?
« Reply #380 on: December 14, 2018, 10:49:02 AM »
This is an annex to the paper "Climatic variations in historic and prehistoric time" By Otto Petersson published in 1912 in UR Svenska Hydrografisk-Biologiska Kommisionens Skrifter
(http://www.mitosyfraudes.org/calen12/petterson_1.html)

It is "The ice conditions and climatic variations in Greenland" http://www.mitosyfraudes.org/calen12/petterson_2.html

I wonder if today's scientists look at these old papers to see if there is data locked way in dusty archives that could throw some light on history, or whether is is all dismissed as irrelevant old stuff.

It begins as follows...

Quote
Even in the age of the Sagas and the Vikings there existed an ice-bearing current on the east and northeast coasts of Greenland. But the current in those days cannot be compared to the present one, neither in extent nor in its importance to navigation. This fact I attribute to a more vivid circulation in the Irminger Sea in former days. According to the researchers of the Danish Ingolf expedition, the bulk of the Gulfstream branch known as the Irminger current turns westward at the entrance to the Denmark Strait and runs along the east coast of Greenland forming the underlayer of the ice-bearing polar current. According to Hambergs investigation in 1883 this warm underlayer melts the ice of the polar current and the amount of drift-ice on the eastcoast of Cape Dan in lat. 65 1/2º will vary with the strength of the Irminger current. South of Cape Farewell the ice turns west and northwest collecting outside the sosuthwestern coast of Greenland (Juliane-haabs Distrikt). Here 8-9 centuries ago the Icelandic colonists found an open sea. Now it is blocked by ice all summer because the Irminger current is too weak to melt de ice before it reaches Cape Farewell.

A small increase in the temperature of the under layer, or a stronger influx of Gulf stream water, or a stronger oscillation in the border-stratum causing a more vivid contact of the waters of the two currents would scatter the drift-ice so that the neighbourhood of Cape Farewell would be free from ice and the deep sounds between that island and the main land open to navigation. Later we shall see the importance of these sounds for the journeys of the Viking-settlers.

The formation of the coast in the lat. of Cape Dan causes the drift-ice to scatter after the passage of the Denmark Sound. The scattering of the ice and the action of the Irminger current which still in its full force crosses over from Iceland to Greenland makes the neighbourhood of Angmangsalik (Cape Dan) more accessible from the east than the southernmost point of Greenland<./p> Nordenskiöld was the first in modern time to profit by this when in 1883 he broke through the thin ice-layer outside Cape Dan and anchored his ship "the Sophia" in King's Oscar's harbour. (lat. 65º 35'). The stronger development of the Irminger current a thousand years ago brought two important consequences:

1. The climate of Österbygden (the eastern settlement) was more temperate because the sea coast was free from ice, whereas the district of Julianehaab has an ice-bound sea in front and the inland-ice behind.

2. As the ice did not go round Cape Farewell and enter Davis Strait, Baffin Bay and the Labrador-current were also relatively free from ice. This again influenced the climate of New Foundland and North America. It is also probable that the warm under current which runs through Davis Strait, like the Irminger current and the rest of the western Gulf stream-branches, was otherwise developed in those days. In other words: that the polar ice then melted at higher latitude than now.

At the end of the Middle-ages a change came in these conditions, which can only be explained by an alteration in the oceanic circulation. Such changes in the oceanic circulation will of course be more perceptible in the border-areas where the waning Gulf stream branch contents with currents of the northern origins as in Cattegat, the Baltic, Baffin Bay and at the south-point of Greenland. It is inconceivable that a state of equilibrium lasting through thousands of years should exist in those parts. Even now the conditions, especially the ice conditions, vary greatly from year to year in these seas. In Greenland there are good ice-years and bad ones. Now I will show the conditions in south Greenland in a good year like 1883 when Nordenskiöld on the Sophia landed at Fredriksdal and penetrated into the sounds north of Cape Farewell which had not been navigated by European ships since the days of the Vikings. Then I will give an instance of the conditions and the route of navigation in a bad year like 1902 as described by the Danish archeologist Captain Bruun.

Finally I will draw a comparison between these conditions and those which prevailed a thousand years ago when Iceland and Greenland were colonized and the Norsemen discovered America. In our time the east coast of Greenland from 65º lat. to Cape Farewell is almost inaccessible.
In good years the pack-ice may form a narrow belt along the coast. But the pressure of this ice-girdle, which is packed close to the coast whenever the wind blows in that direction, is almost more formidable to navigators than in bad years when the ice spreads for miles over the sea but generally leaves an open channel along the shore. This channel was used by the Danish expeditions under Graah, Holm and Garde o.a. Nansen too used this channel to get to the point from whence he started on his ice-wandering after he had landed on the drift-ice and carried his boats across it, just as they did in cases of emergency in ancient times, as is told in Kungaspegeln (the King Mirror) from the 13th century. Doubtless 600-700 years ago it was at times dangerous and even impossible to penetrate to the east coast of Greenland if it happened to be a bad ice-year.

But it must be remembered that in the Viking-age such years were exceptions and not the rule as is now the case. In spite of the strong tidal currents the sounds between Cape Farewell and the mainland are now always blocked by drift-ice which is crammed into their eastern inlets by the polar current outside. West of Cape Farewell there is the great fjord-district with the settlements of the ancient "Eystribyggd". All summer the Bay is blocked by drift-ice, and navigation is generally impossible till authum and then only by circuitous routes as shown by the dotted lines in the map of plate 11.

Circumstances being exceptionally favourable, Nordenskiöld was able to get to Julianehaab as early as the 17th June 1883. It is generally necessary to wait till late in summer and, working through the ice-girdle, make the coast by the northliest route through Nunarsiut Sound then go south-wards on an inner route along the coast of Julianehaab and Fredriksdal which is the farthest accessible settlement. From here the expeditions of Wallö, Giesecke, Graah, Holm and Garde in Eskimo boats penetrated through the sounds north of Cape Farewell: the Ikerasak, the Ikek, the Tunua, the Kipisak a. o. which, though never sounded, were found to be navigable up to their eastern inlets, where the ice of the polar current was encountered. In spite of the favourable conditions in 1883 Nordenskiöld had no better luck. He was turned back by the ice when trying to penetrate through the sounds and was unable to reach the east coast. Such are the conditions in a good ice-year. The ice-charts of 1903 and Captain Bruun's description of his journey to Greenland in the summer 1903 show how the navigation must be performed in a bad year.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Klondike Kat

  • ASIF Citizen
  • Posts: 160
    • View Profile
  • Liked: 5
  • Likes Given: 15
Re: What's new in Greenland?
« Reply #381 on: December 14, 2018, 03:01:46 PM »
Very nice gerontocrat.

Do you know how conditions today compare to those in the past?

gerontocrat

  • ASIF Governor
  • Posts: 3620
    • View Profile
  • Liked: 359
  • Likes Given: 7
Re: What's new in Greenland?
« Reply #382 on: December 14, 2018, 10:07:08 PM »
Very nice gerontocrat.

Do you know how conditions today compare to those in the past?
The following article describes how the little ice age that was supposed to have driven away the Viking settlers from Greenland is a myth.

What is true that the remnants of those settlements are now melting away.

https://www.businessinsider.com/greenlands-melting-ice-exposes-ancient-artifacts-2016-10?r=US&IR=T
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

johnm33

  • ASIF Upper Class
  • Posts: 1030
    • View Profile
  • Liked: 40
  • Likes Given: 8
Re: What's new in Greenland?
« Reply #383 on: Today at 11:54:08 AM »
There was a Canadian academic who made quite a study of the Viking presence throughout the archipelago, mining on Axel Heiberg/Victoria/Banks as well as the west coast of Greenland. If I remember her name I'll find a link. For them to have been there suggests the archipelago was seasonally navigable. That it suddenly altered is suggested by the blond inuit tribe that was discovered and that equally suddenly long houses appeared down the Pacific coast. Iirc her findings were deemed too sensitive politically and she lost her funding.