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The Greenland Thread

Re: The Greenland Thread

Unread postby dohboi » Sat 25 Aug 2018, 19:15:23

Ummmmm.....I kinda doubt that Greenland has drained all of the heat out of the earth's molten core! :lol: :lol: :lol:
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Re: The Greenland Thread

Unread postby Tanada » Sat 25 Aug 2018, 21:07:32

vtsnowedin wrote:
kanon wrote:
Plant I did check it out months ago, see my old posts, at current rates it will take 15,000 years for all the ice to melt.

What happens if it rains? What is the possibility of a hurricane moving over Greenland and dropping a lot of liquid water? I suspect the chances of that type event are increasing.
Even at the height of the summer melt season a hurricane type storm would be a snow event over much of the island because of the altitude. The top of the ice pack averages 7000 feet above sea level.
A major storm might power scrub the coast and push back the glacier ends inland a bit but the main mass of ice would just shrug it off and might even gain from the increased snow fall.


I think your math is kind of fuzzy. Adiabatic cooling with altitude averages 3 degrees F for every 1000 feet or 21 degrees for 7000 feet. A tropical rainstorm event with 60 degree F raindrops will still be dropping 39 degree raindrops at 7000 feet and rainwater at that temperature can melt a LOT of ice.
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Re: The Greenland Thread

Unread postby vtsnowedin » Sun 26 Aug 2018, 18:28:41

dohboi wrote:Ummmmm.....I kinda doubt that Greenland has drained all of the heat out of the earth's molten core! :lol: :lol: :lol:
No of course not but any extra heat sent up under Greenland fifty million years ago has already dissipated to some level less then when it first occurred and today most certainly has less impact then it did during the last ice age 20,000 years ago.
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Re: The Greenland Thread

Unread postby vtsnowedin » Sun 26 Aug 2018, 18:33:13

Tanada wrote:
vtsnowedin wrote:
kanon wrote:
Plant I did check it out months ago, see my old posts, at current rates it will take 15,000 years for all the ice to melt.

What happens if it rains? What is the possibility of a hurricane moving over Greenland and dropping a lot of liquid water? I suspect the chances of that type event are increasing.
Even at the height of the summer melt season a hurricane type storm would be a snow event over much of the island because of the altitude. The top of the ice pack averages 7000 feet above sea level.
A major storm might power scrub the coast and push back the glacier ends inland a bit but the main mass of ice would just shrug it off and might even gain from the increased snow fall.

I think your math is kind of fuzzy. Adiabatic cooling with altitude averages 3 degrees F for every 1000 feet or 21 degrees for 7000 feet. A tropical rainstorm event with 60 degree F raindrops will still be dropping 39 degree raindrops at 7000 feet and rainwater at that temperature can melt a LOT of ice.

What makes you think that a cyclonic storm at those Latitudes would produce rainfall at sea level at 60 degrees F.??
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Re: The Greenland Thread

Unread postby rockdoc123 » Sun 26 Aug 2018, 18:36:35

No of course not but any extra heat sent up under Greenland fifty million years ago has already dissipated to some level less then when it first occurred and today most certainly has less impact then it did during the last ice age 20,000 years ago.


there are a host of papers out there on the subject of the Icelandic hot spot and its trace across Greenland along with estimates of current Greenland heat flow. As I pointed out that direct measure is above that which will cause basal melt on glaciers. Note the heat does not carry up through the entirety of the ice sheet that is quite thick but does have an impact on the ice/bedrock interface. Realize there is already some amount of pressure melting as a consequence of the heavy gravitational load. If you think of the P/T relationship in the appropriate phase diagram it is easy to see how increased basement heat flow would allow for greater basal melt. The same relationship is noted in Western Antartica, again with a number of recent publications that outline measurements and indirect estimates.
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Re: The Greenland Thread

Unread postby vtsnowedin » Sun 26 Aug 2018, 19:05:29

rockdoc123 wrote: If you think of the P/T relationship in the appropriate phase diagram it is easy to see how increased basement heat flow would allow for greater basal melt. .
But how would an event fifty million years ago cause an increase in heat flow today?
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Re: The Greenland Thread

Unread postby rockdoc123 » Sun 26 Aug 2018, 19:52:08

But how would an event fifty million years ago cause an increase in heat flow today?


The high heat flow is a relic of the passage of Greenland over the Icelandic hot spot.

Martos, Y. M. et al, 2018. Geothermal heat flux reveals the Iceland Hotspot Track underneath Greenland. Geoph Res Lett, https://doi.org/10.1029/2018GL078289

Curie depths beneath Greenland are revealed by spectral analysis of data from the World Digital Magnetic Anomaly Map 2. A thermal model of the lithosphere then provides a corresponding geothermal heat flux map. This new map exhibits significantly higher frequency but lower amplitude variation than earlier heat flux maps and provides an important boundary condition for numerical ice‐sheet models and interpretation of borehole temperature profiles. In addition, it reveals new geologically significant features. Notably, we identify a prominent quasi‐linear elevated geothermal heat flux anomaly running northwest–southeast across Greenland. We interpret this feature to be the relic of the passage of the Iceland hotspot from 80 to 50 Ma. The expected partial melting of the lithosphere and magmatic underplating or intrusion into the lower crust is compatible with models of observed satellite gravity data and recent seismic observations. Our geological interpretation has potentially significant implications for the geodynamic evolution of Greenland.
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Re: The Greenland Thread

Unread postby vtsnowedin » Mon 27 Aug 2018, 18:22:41

He has one hell of an engineering academician thesaurus working for him there, but I fail to see anything he says translates into English saying that the underside of Greenland is hotter today then it was ten thousand years ago.
He is just a bull s#!ter looking for his next research grant and salary.
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Re: The Greenland Thread

Unread postby rockdoc123 » Mon 27 Aug 2018, 19:51:40

He has one hell of an engineering academician thesaurus working for him there, but I fail to see anything he says translates into English saying that the underside of Greenland is hotter today then it was ten thousand years ago.
He is just a bull s#!ter looking for his next research grant and salary.


If you can't understand what is being said in the paper then you really have no business questioning the interpretation. But apparently, you know better than the various authors who have published a number of papers on this topic (this is just the latest one) as well as all the associate editors who were involved in peer review. If you can argue scientifically why their interpretation of a "quasi-linear elevated geothermal heat flux anomaly" running across Greenland is incorrect then have at it. Or maybe you have access to a scientific paper that indicates there is no geothermal anomaly below Greenland, please share that with us all.

Otherwise it would appear you are the "bull s#!ter"
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Re: The Greenland Thread

Unread postby vtsnowedin » Tue 28 Aug 2018, 09:14:16

[quote="rockdoc123]
a "quasi-linear elevated geothermal heat flux anomaly" running across Greenland [/quote]
An almost, but not quite, straight line increase in bedrock temperature change from the historic or expected average running across Greenland.!!….
A lot of words to say not much at all other then they can still measure the tract of the magmas course. That does not lead to the conclusion that the bedrock under Greenland is getting warmer today then it was say 10,000 years ago. Only readers whose eyes glazed over reading the self aggrandizing text would draw that wrong conclusion.
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Re: The Greenland Thread

Unread postby rockdoc123 » Tue 28 Aug 2018, 09:33:51

A lot of words to say not much at all other then they can still measure the tract of the magmas course. That does not lead to the conclusion that the bedrock under Greenland is getting warmer today then it was say 10,000 years ago. Only readers whose eyes glazed over reading the self aggrandizing text would draw that wrong conclusio


the paper is not arguing it is getting warmer, what it is arguing is that there is a region of increased basement heat flow as a consequence of the passing of the continent over a hot spot. Based on another recent paper

Rysgarrd, S et al, 2018. High geothermal heat flux in close proximity to the Northeast Greenland Ice Stream. Scientific Reports,8, 1344

The Greenland ice sheet (GIS) is losing mass at an increasing rate due to surface melt and flow acceleration in outlet glaciers. Currently, there is a large disagreement between observed and simulated ice flow, which may arise from inaccurate parameterization of basal motion, subglacial hydrology or geothermal heat sources. Recently it was suggested that there may be a hidden heat source beneath GIS caused by a higher than expected geothermal heat flux (GHF) from the Earth’s interior. Here we present the first direct measurements of GHF from beneath a deep fjord basin in Northeast Greenland. Temperature and salinity time series (2005–2015) in the deep stagnant basin water are used to quantify a GHF of 93 ± 21 mW m−2 which confirm previous indirect estimated values below GIS. A compilation of heat flux recordings from Greenland show the existence of geothermal heat sources beneath GIS and could explain high glacial ice speed areas such as the Northeast Greenland ice stream.


that measured heat flow is at a level which would accentuate basal melt, much as has been demonstrated for the West Antarctic ice sheet. The bottom line here is that attribution of glacier melt or flow speed totally to surface or ocean warming is incorrect. This is important to predictions of future behavior.

Also I need to point out that heat flow is not something that is static, it changes considerably. Measurement taken over the years from the East Arican rift system show considerable fluctuations. In the case of Greenland the overall picture is further complicated inasmuch as a portion is transitional crust rather than continental crust, meaning the heat flow is naturally higher.
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Re: The Greenland Thread

Unread postby Newfie » Thu 20 Sep 2018, 17:06:18

Here is a short article about research in Greenland

https://gcaptain.com/harsh-climate-the- ... evel-rise/

Also here is a short book that is very well written. A story of a man and his two sons who visit the French base in Antarctica. Very remote. It gives a glimpse of what artic research is like, warts and all. Download is under $6.

I have an online acquaintance with the skipper, quite a knowledgeable young man. Very impressive.

https://www.amazon.com/Snow-Petrel-Tuck ... B0091EP4B6
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Re: The Greenland Thread

Unread postby Tanada » Sat 22 Sep 2018, 09:52:36

Climate modeling discussion moved to the correct thread CLIMATE please reserve this thread for Greenland specific posts.
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Re: The Greenland Thread

Unread postby dohboi » Wed 03 Oct 2018, 17:45:23

Atmospheric rivers melt Greenland

Nature Climate Change 8, 857-858, DOI: https://doi.org/10.1038/s41558-018-0297-4

http://www.nature.com/articles/s41558-018-0297-4

Abstract: "Recent years have seen increased melting of the Greenland Ice Sheet, contributing to accelerated rates of sea-level rise. New research suggests that this melting is due to an increased frequency of atmospheric rivers, narrow filaments of moist air moving polewards."
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Re: The Greenland Thread

Unread postby Keith_McClary » Mon 15 Oct 2018, 17:22:26

dohboi wrote:Atmospheric rivers melt Greenland

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Re: The Greenland Thread

Unread postby dohboi » Thu 10 Jan 2019, 12:51:30

Warming of SE Greenland shelf waters in 2016 primes large glacier for runaway retreat

https://www.the-cryosphere-discuss.net/tc-2018-260/
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Methane monster on GIS

Unread postby Whitefang » Fri 11 Jan 2019, 03:40:34

http://www.bristol.ac.uk/news/2019/janu ... hane-.html

An international team of researchers led by the University of Bristol camped for three months next to the Greenland Ice Sheet, sampling the meltwater that runs off a large catchment (> 600 km2) of the Ice Sheet during the summer months.
As reported in Nature, using novel sensors to measure methane in meltwater runoff in real time, they observed that methane was continuously exported from beneath the ice. They calculated that at least six tons of methane was transported to their measuring site from this portion of the Ice Sheet alone, roughly the equivalent of the methane released by up to 100 cows.


Tons of methane……..only 6 for 600 km2, GIS is about 1500000 km2 so that might imply 15000 ton of methane, not that much compared to a Gton. Another day, another feedback...…

Thinking last night on Atlantification, what if there is equal Arctification of the North Atlantic?
The Gyre holds 8000 cubic km, GIS about 4 million but that cannot be released instantly, data already shows that huge cold surface layer of fresh water on top of the warm current flowing northeast.
Would the North Atlantic South East of Greenland be stratified with the onset of current Heinrich event or the start of the Gyre reversal? Weakening of the Golfstream only adds to that effect.
After BOE with the cold pole above central Greenland, Canadian cold from the barren will probably head for Africa along the habits of the new polar vortex, chilling the surface water even more.


Just wondering ya know :roll:

Darn, I cannot wait to see what is happening, yet I do not want what it will cause, abrupt CC, loss of harvest and habitat.
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Re: The Greenland Thread

Unread postby dohboi » Mon 11 Feb 2019, 21:16:54

Arctic Sea Ice Loss in Past Linked to Abrupt Climate Events

https://m.phys.org/news/2019-02-arctic- ... inked.html
A new study on ice cores shows that reductions in sea ice in the Arctic in the period between 30,000 -100,000 years ago led to major climate events.

During this period, Greenland temperatures rose by as much as 16 degrees Celsius.

The results are published today (Monday 11 February) in Proceedings of the National Academy of Sciences (PNAS).


Louise C. Sime el al., "Impact of abrupt sea ice loss on Greenland water isotopes during the last glacial period," PNAS (2019).

...


NASA Finds Possible Second Impact Crater Under Greenland Ice
https://www.eurekalert.org/pub_releases ... 021119.php

A NASA glaciologist has discovered a possible second impact crater buried under more than a mile of ice in northwest Greenland.

His follows the finding, announced in November 2018, of a 19-mile-wide crater beneath Hiawatha Glacier - the first meteorite impact crater ever discovered under Earth's ice sheets. Though the newly found impact sites in northwest Greenland are only 114 miles apart, at present they do not appear to have formed at the same time.

If the second crater, which has a width of over 22 miles, is ultimately confirmed as the result of a meteorite impact, it will be the 22nd largest impact crater found on Earth.



... Following the finding of that first crater, MacGregor checked topographic maps of the rock beneath Greenland's ice for signs of other craters. Using imagery of the ice surface from the Moderate Resolution Imaging Spectroradiometer instruments aboard NASA's Terra and Aqua satellites, he soon noticed a circular pattern some 114 miles to the southeast of Hiawatha Glacier. The same circular pattern also showed up in ArcticDEM, a high-resolution digital elevation model of the entire Arctic derived from commercial satellite imagery.

To confirm his suspicion about the possible presence of a second impact crater, MacGregor studied the raw radar images that are used to map the topography of the bedrock beneath the ice, including those collected by NASA's Operation IceBridge. What he saw under the ice were several distinctive features of a complex impact crater: a flat, bowl-shaped depression in the bedrock that was surrounded by an elevated rim and centrally located peaks, which form when the crater floor equilibrates post-impact. Though the structure isn't as clearly circular as the Hiawatha crater, MacGregor estimated the second crater's diameter at 22.7 miles. Measurements from Operation IceBridge also revealed a negative gravity anomaly over the area, which is characteristic of impact craters.

"The only other circular structure that might approach this size would be a collapsed volcanic caldera," MacGregor said. "But the areas of known volcanic activity in Greenland are several hundred miles away. Also, a volcano should have a clear positive magnetic anomaly, and we don't see that at all."

Although the newly found impact craters in northwest Greenland are only 114 miles apart, they do not appear to have been formed at the same time. From the same radar data and ice cores that had been collected nearby, MacGregor and his colleagues determined that the ice in the area was at least 79,000 years old. The layers of ice were smooth, suggesting the ice hadn't been strongly disturbed during that time. This meant that either the impact happened more than 79,000 years ago or -- if it took place more recently -- any impact-disturbed ice had long ago flowed out of the area and been replaced by ice from farther inland.

Open Access: Joseph A. MacGregor et al. A Possible Second Large Subglacial Impact Crater in Northwest Greenland, Geophysical Research Letters (2019).

(Thanks to vox at asif for these)
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Re: The Greenland Thread

Unread postby Whitefang » Fri 01 Mar 2019, 13:19:00

https://www.youtube.com/watch?v=WGmJgJ1d02Y

Between 60,000 and 22,000 years ago there were numerous abrupt temperature fluctuations recorded by oxygen and nitrogen isotopes (paleo-thermometer proxies) in Greenland ice cores. Temperatures over parts of Greenland rose by up to 16.5 C within a decade or two, in the largest of these so-called Dansgaard-Oescher (D-O) Oscillations. I chat on the latest science, about how a lack of Arctic sea-ice was the primary factor. This is crucial info to help us figure out what will happen to Greenland when we have no surrounding sea ice left.



DO events are 95% correlated to sea ice loss, sea surface temperature being the most important aspect, number in CC.
Part 2 of video from last week.

https://www.youtube.com/watch?v=SA1y73Dje4U

Glaciers on Greenland and Antarctica are rapidly melting due to Abrupt Climate Change, and melt rates are doubling with a period of roughly 7 years. This is exponential, after 7 years melt rates are double (2x), after 14 years rates are 4x, after 21 years rates are 8x, etc...In this video and the next I discuss consequences that are rarely considered, like reduced gravitational pull near the glaciers, isostatic rebound, and reduction of vertical ocean mixing from surface freshwater lensing effects, leading to increased basal ice sheet melting.



Gravitational effects.....interesting facts on ice sheet collapse
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Re: The Greenland Thread

Unread postby vtsnowedin » Fri 01 Mar 2019, 14:43:34

I note that humans had nothing to do with the DO event of 11,000years ago which raised temps 8 degrees C.
From the wiki article:
In the Northern Hemisphere, they take the form of rapid warming episodes, typically in a matter of decades, each followed by gradual cooling over a longer period. For example, about 11,500 years ago, averaged annual temperatures on the Greenland ice sheet warmed by around 8 °C over 40 years, in three steps of five years (see,[3] Stewart, chapter 13), where a 5 °C change over 30–40 years is more common.
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