The melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred.
This makes you wonder what other kinds of issues remain undetected in the satellite data. NSIDC has had to issue corrections in the past, when it was pointed out that their data and reality didn’t match. – Anthony
The algorithm for the Greenland Ice Sheet Today daily melt extent has been revised to account for unusually warm winter snow layers and residual meltwater deep in the snow. Meltwater from last summer’s intense melt season did not completely re-freeze through at least mid December. The adjusted algorithm shows greatly reduced melt extent for early 2013. This much lower extent is more consistent with available weather and climate records.
Melt extent and distribution
Figure 1. These images show cumulative melt extent before the algorithm correction (left) and after the correction (right). A few areas indicating one to two days of melting in southeast Greenland remain in the revised map. The red dot shows the location of the Danish AWS. Credit: National Snow and Ice Data Center – Click for hires imageAs shown in Figure 1, the adjustment to the algorithm resulted in fewer melt days than previously indicated. The revised image at right shows new surface melting in 2013 in a few small areas along the central southeastern Greenland coast, within the region of earlier spurious melt signals but greatly reduced.
Conditions in context
Figure 2. This image shows air temperature anomaly for Greenland for the period December 2012 to February 2013. Reds and oranges indicate higher than average air temperatures. The temperatures shown are at approximately 1,500 meters (5,000 feet) in altitude, appropriate for coastal Greenland regions. However, central Greenland is above this altitude, and values shown there do not represent the true surface conditions well. Credit: National Snow and Ice Data Center courtesy NOAA ESRL Physical Sciences DivisionTemperatures in Greenland have been higher than average this winter, with air temperatures near the coast averaging 2.0 to 3.5 degrees Celsius (4 to 6 degrees Fahrenheit) warmer than the 1981 to 2010 average. This has in part been a result of the persistent circulation pattern for the Arctic this winter, characterized by a negative Arctic Oscillation (AO). The AO is a measure of the intensity of the general pattern of low pressure over the northern high latitudes. A negative AO indicates higher-than-average pressures near the North Pole, allowing more frequent southward cold air outbreaks, and more intrusions of warm air masses from higher temperature areas. Despite these anomalously high temperatures along the Greenland coast, temperatures were not high enough to result in melting.
Adjusted algorithm and melt images
Figure 3. This plot shows surface air temperature at a PROMICE on-ice Automated Weather Station (AWS) near the southeastern Greenland ice sheet edge for early 2013. Temperatures did not exceed freezing at this site. Data from PROMICE were provided by the Geological Survey of Denmark and Greenland (GEUS) and are freely available. Credit: National Snow and Ice Data Center and J. Box, Geological Survey of Denmark and GreenlandThe melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred. While the algorithm was indicating some coastal melt in February and early March, a comparison with weather data for Nuuk (the Greenland capital city, located along the southwest of the island) and data from the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) suggested these might be spurious melt readings. The local Automated Weather Station (AWS) data from a glacier along the southeastern coast (the Mittivakkat glacier AWS, shown by a red dot in Figure 1; data in Figure 3) indicate that the air temperature did not rise to the melting point (0 degrees Celsius, or 32 degrees Fahrenheit) in February or early March.
Figure 4. A model of the snowpack conditions indicates residual liquid water in the deep snowpack in southeastern Greenland. Credit: National Snow and Ice Data Center and X. Fettweis, Université de Liège, BelgiumDuring this period, starting around mid-February in southeast Greenland, the brightness temperatures in the upper few meters of the snowpack were 2 to 10 degrees Celsius (4 to 18 degrees Fahrenheit) higher than those observed during any other year in the 34-year record (1979 to 2012). While surface melt is not unprecedented in Greenland near the coast in February and March, the totals posted prior to March 14 were a result of these unusual snow temperature conditions, and not ongoing surface melt. This winter has seen unusually warm snow at depth on the ice sheet, following the intense melting that occurred last summer.
The melt detection method, based on passive microwave emissions, is primarily sensitive to near-surface conditions, but has some input from the snowpack down several meters (10 to 20 feet). Heavy snow fell during the relatively warm winter, burying and insulating deeper snow. This contributed to anomalously high temperatures for the uppermost layers of snow this winter. Additionally, models based on snowpack properties suggested that some 2012 meltwater remained unfrozen at 5 meters depth (approximately 16 feet) in mid-December. The model results are consistent with observations from JAXA’s AMSR-2 sensor.
The algorithm was adjusted by combining the trend of observed brightness temperatures with a model of the expected microwave emission in the channels used for melt detection (the SSM/I sensor’s 37 GHz Horizontal polarization channel). This adjustment is generally performed every year in March to calibrate the melt detection thresholds. However, because of the unusual condition of the snowpack, the adjustment needed to be made much earlier than ever before.
Further information
Fettweis, X., M. Tedesco, M. van den Broeke, and J. Ettema, 2011. Melting trends over the Greenland ice sheet (1958-2009) from spaceborne microwave data and regional climate models. The Cryosphere 5, 359-375, doi: 10.5194/tc-5-359-2011.
For johnmarshall: Nothing about the warmists scare reports is real by definition!
Ian
March 22, 2013 3:55 am
I think the conversion is incorrect re Celsius to Fahrenheit ..being Canadian, I recognized this immediately :
” During this period, starting around mid-February in southeast Greenland, the brightness temperatures in the upper few meters of the snowpack were 2 to 10 degrees Celsius (4 to 18 degrees Fahrenheit) higher than those observed during any other year in the 34-year record (1979 to 2012). ”
2 Degrees C = 35 F
10 degrees C = 50 degrees F
however, if they meant the other way around.
4 degrees F = minus 15 or ( -15 C)
18 degrees F = minus 7 C or ( -7 C )
so which did they mean….
Richard Day
March 22, 2013 4:29 am
Our algo was off but we’re still believers in the church of global warming. By the way, we need a 14% increase in our funding. Bonuses and such.
Jimbo
March 22, 2013 4:29 am
For newbies obsessed that something is wrong in Greenland please take a look at the following. It looks like natural cycles to me.
Abstract
….The record indicates that warmer temperatures were the norm in the earlier part of the past 4000 years, including century-long intervals nearly 1°C warmer than the present decade (2001–2010). Therefore, we conclude that the current decadal mean temperature in Greenland has not exceeded the envelope of natural variability over the past 4000 years, a period that seems to include part of the Holocene…..
[Takuro Kobashi et. al.]
——- Abstract
An aerial view of 80 years of climate-related glacier fluctuations in southeast Greenland
…………the recent retreat was matched in its vigour during a period of warming in the 1930s with comparable increases in air temperature. We show that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s,……
[Anders A. Bjørk et. al.]
——- Abstract
“…the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005….”
[Petr Chylek et. al.]
——- Abstract
“…The annual whole ice sheet 1919–32 warming trend is 33% greater in magnitude than the 1994–2007 warming….”
[Jason E. Box et. al.]
——- Abstract
“…The warmest year in the extended Greenland temperature record is 1941, while the 1930s and 1940s are the warmest decades….”
[B. M. Vinther et. al.]
——- Abstract
The State of the West Greenland Current up to 1944
“….It is found that warmer conditions existed during the decade of 1880, followed by a colder period up to about 1920, when the present warm period began. The peak of the present warm period appears to have been reached in the middle 1930’s,…..”
[M. J. Dunbar]
This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs? Without validation, what these people are doing is not “science”, it’s computer games!
By the way, I’ve become real familiar with the errors occurring in the GISS maps used by county planners and the various on-line mapping services. Errors such as drainage ditches labeled as roads, large farm equipment labeled as barns or sheds or silos, and so on. The GISS people don’t do a good job of validating their programs either.
Marcos
March 22, 2013 5:16 am
i’m confused. why are satellite sensor results being put into a computer model to come up with its ‘data’? shouldn’t the sensor data, oh i dont know, be the data?
PaulH
March 22, 2013 5:28 am
So “Greenland Is Melting! Melting!” was front page news. Will this correction appear on Page 1, or will it be buried somewhere in the classifieds?
starzmom
March 22, 2013 5:43 am
For another slightly OT anomalous weather update, here in eastern Kansas we are expecting 9-12 inches of snow for Palm Sunday. At this rate my easter dress will be heavy wool with boots. And the forsythia have yet to show themselves.
Owen in GA
March 22, 2013 5:54 am
Ian says:
March 22, 2013 at 3:55 am
I think the conversion is incorrect re Celsius to Fahrenheit ..being Canadian, I recognized this immediately… :
Ian, I think they are talking differences in temperature rather than absolute readings. If something is 2C warmer, it is 18/5 F warmer (3.6F). You interpreted it to say the snow was 2 to 10 degrees C which is an impossibility as it would have melted.
Scott
March 22, 2013 6:38 am
Jayhd says
march 22, 2013 at 4:59 am
… but don’t these “scientists” and computer “experts” validate their satellite data …
A couple things about validation, to be a good validator you have to be skeptical of everything and not afraid of finding something wrong and potentially embarrassing to your organization. So you really can’t be the same guy who designed the satellite or comes up with the data … you are too close and would have too much to lose. When you are a validator you take off your “team player” hat for a while. So I can see how that’s a problem for the global warming community.
But there is a way around this. I’ve had a few validation projects and we couldn’t get half the guys to leave their computers and get out in the plant and find something we didn’t already know. They wanted to validate everything from their computer rather than walking a quarter mile in the plant. Really frustrating. They avoid the tough part about validating by not really validating.
Guys like Anthony should be the validators, not the scientists or computer experts.
numerobis
March 22, 2013 6:39 am
“This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs?”
Isn’t that what the story says they did? They noticed the model was wrong by checking measurements on the ground; so they fixed the model.
ferd berple
March 22, 2013 6:46 am
Jimbo says:
March 22, 2013 at 4:29 am
Cache of historical Arctic sea ice maps discovered
===============
The old nautical charts from England’s golden age of exploration show that sea levels have not risen anything like what is currently believed. These charts are still highly accurate even today, and most of the modern nautical charts are simply copies of these older charts, with corrections for wrecks, rocks missing in the original surveys, and datum adjustments for GPS.
Very few areas worldwide have ever been re-surveyed due to the high cost. Yet, almost universally, if a rock was shown on the charts as awash at low tide 200-300 years ago, it is still awash at low tide today. If sea levels were truly rising, these rocks should no longer be visible at low tide. Nowhere on the charts is a datum adjustment for “sea level rise”.
Which is very strange. These charts are vital to preventing loss of ships and lives. You would think that if sea level rise was real, these charts would have been updated to reflect this.
The reason they have not is quite simple. If the charts were adjusted to show sea levels rising when it has not, then this would result in water depths being reported as deeper than they really are. This would result in ships running aground when they thought they were safe, resulting in the loss of ships and lives.
Thus, nautical charts are one of the best sources of information on sea level rise over the past 2-3 hundred years, and why to this date they have not been used to calibrate sea level rise. Instead we see endless tidal gauges mounted on sand and mud, or sea shells or tea leaves used a proxies.
Admad
March 22, 2013 6:49 am
Am I missing something here? Why would something which is readily observable have to be “modelled”?
beng
March 22, 2013 6:49 am
The cold weather in Scandinavia has something to do w/the Greenland east coast. Easterly winds from there have been crossing the N Atlantic to hit Greenland. That air isn’t Arctic by that time — not even below freezing.
It’s called weather.
Billy Liar
March 22, 2013 6:49 am
Can some genius at NSIDC please generate an outline of the 1500m contour on Greenland, place it on their anomaly map (Fig 2) and set the color inside the contour to white.
The anomaly map would then appear a tad more honest: showing fictitious anomalies below the surface of the ice is somewhat bizarre to say the least.
This case shows up the folly of overreliance on algorithms, statistics and computer models, and not paying enough attention to real world data.
This was illustrated well with the issue of GHCN temperature adjustments in Iceland. In 1965, Iceland underwent a drastic drop in temperatures. The cold spell lasted well into the 1970’s, and was so severe that agriculture and fishing suffered hugely, leading to mass unemployment and 50% currency devaluation. This time even had a name, “The Sea Ice Years”, and has been well researched by proper scientists.
Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.
There’s more on the background to the Sea Ice Years here. http://notalotofpeopleknowthat.wordpress.com/2012/10/30/ghcn-temperature-adjustments-in-icelanda-closer-look-at-stykkisholmurpart-ii/
Chris4692
March 22, 2013 6:57 am
Village Idiot says:
March 21, 2013 at 11:37 pm
Proof (if we needed it) that the “Unprecedented Greenland Ice Sheet Surface Melt” of 2012 didn’t really happen
(Others as well)
The article says no such thing. It applies to recalibrating 2013 data, not 2012. It even refers to the water from the ice melt of last summer remaining unfrozen under the surface.
Although there are reasons to think that last summers melt was not unprecedented, this article is not one of them.
ferd berple
March 22, 2013 6:59 am
ps: there is good reason to increase water depth on nautical charts if sea level rise is occurring. Increased water depth opens up new sea-lanes and can save millions in costs. It is not unusual for ships to travel in areas where the difference between a safe passage and running aground is less than the difference between high and low tide for that day.
ferd berple
March 22, 2013 7:04 am
Paul Homewood says:
March 22, 2013 at 6:53 am
Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.
===========
Very interesting. This shows the problems in adjusting temperatures to try and improve signal quality. What the computer thinks is noise may well be signal, and what the computer this is signal may well be noise.
This is in some way similar to the famous hockey stick, where in an attempt to amplify the signal in tree rings via “calibration” what actually happened was an amplification of noise. Since this noise was random it gave the appearance that temperatures had not changed for 1000 years and we all got the shaft as a result.
John F. Hultquist
March 22, 2013 7:06 am
jayhd says:
March 22, 2013 at 4:59 am
“. . . actually going to a sampling of sites and getting real data . . .”
Such real data was called ‘ground truth’ and getting such was called “ground truthing.”
I remember it well, much like a beer for 25¢. http://en.wikipedia.org/wiki/Ground_truth
knr
March 22, 2013 7:08 am
How lucky do you have to be to find all the ‘mistakes’ work in favour of the ideas your pushing ?
RE: Paul Homewood. Thanks for the link. I like your site.
Darren Potter
March 22, 2013 7:40 am
Now where is Mr. CostCo who was defending NASA’s Greenland ice loss and sea level measurements via satellite (http://wattsupwiththat.com/2012/12/03/why-ice-loss-and-sea-level-measurements-via-satellite-and-the-new-shepard-et-al-paper-are-highly-uncertain-at-the-moment/)
doubting possible issues of unknown errors and unaccounted for drift with remarks like:
“I have technical knowledge in the satellite and instrument domains …”
Mr. CostCo: “Basically you’re insinuating that the glaciological community as a whole does not know how to assess errors and neither does Nature/Science etc”
Wonder what Mr. CostCo would deem failing to properly assess errors that allowed a hosed algorithm involved in measuring Greenland’s Ice Sheets to go undetected until after Shepherd et al paper was touted? Possibly the old ‘Nothing to See Here, Move Along’?
Steve from Rockwood
March 22, 2013 7:44 am
Now why didn’t I read this in my local paper? They carried the unprecedented melting story…
J. Gary Fox
March 22, 2013 7:45 am
Great story with details on “Glacier Girl” … above comment by Rational Db8 on WWII planes buried in Greenland. http://www.damninteresting.com/exhuming-the-glacier-girl/
Do we know which glacier was it that the 8 planes landed on?
Is it one of the “fast melting” glaciers listed As Rational noted, if so, how did they get buried in 268 feet of accumulated snow in 50 years?
For johnmarshall: Nothing about the warmists scare reports is real by definition!
I think the conversion is incorrect re Celsius to Fahrenheit ..being Canadian, I recognized this immediately :
” During this period, starting around mid-February in southeast Greenland, the brightness temperatures in the upper few meters of the snowpack were 2 to 10 degrees Celsius (4 to 18 degrees Fahrenheit) higher than those observed during any other year in the 34-year record (1979 to 2012). ”
2 Degrees C = 35 F
10 degrees C = 50 degrees F
however, if they meant the other way around.
4 degrees F = minus 15 or ( -15 C)
18 degrees F = minus 7 C or ( -7 C )
so which did they mean….
Our algo was off but we’re still believers in the church of global warming. By the way, we need a 14% increase in our funding. Bonuses and such.
For newbies obsessed that something is wrong in Greenland please take a look at the following. It looks like natural cycles to me.
On last year’s ‘unprecedented’ melt it appears to have been caused by soot according to the Guardian. Though in happened in 1889.
Rediscovered photos reveal Greenland’s glacier history
Cache of historical Arctic sea ice maps discovered
This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs? Without validation, what these people are doing is not “science”, it’s computer games!
By the way, I’ve become real familiar with the errors occurring in the GISS maps used by county planners and the various on-line mapping services. Errors such as drainage ditches labeled as roads, large farm equipment labeled as barns or sheds or silos, and so on. The GISS people don’t do a good job of validating their programs either.
i’m confused. why are satellite sensor results being put into a computer model to come up with its ‘data’? shouldn’t the sensor data, oh i dont know, be the data?
So “Greenland Is Melting! Melting!” was front page news. Will this correction appear on Page 1, or will it be buried somewhere in the classifieds?
For another slightly OT anomalous weather update, here in eastern Kansas we are expecting 9-12 inches of snow for Palm Sunday. At this rate my easter dress will be heavy wool with boots. And the forsythia have yet to show themselves.
Ian, I think they are talking differences in temperature rather than absolute readings. If something is 2C warmer, it is 18/5 F warmer (3.6F). You interpreted it to say the snow was 2 to 10 degrees C which is an impossibility as it would have melted.
Jayhd says
march 22, 2013 at 4:59 am
… but don’t these “scientists” and computer “experts” validate their satellite data …
A couple things about validation, to be a good validator you have to be skeptical of everything and not afraid of finding something wrong and potentially embarrassing to your organization. So you really can’t be the same guy who designed the satellite or comes up with the data … you are too close and would have too much to lose. When you are a validator you take off your “team player” hat for a while. So I can see how that’s a problem for the global warming community.
But there is a way around this. I’ve had a few validation projects and we couldn’t get half the guys to leave their computers and get out in the plant and find something we didn’t already know. They wanted to validate everything from their computer rather than walking a quarter mile in the plant. Really frustrating. They avoid the tough part about validating by not really validating.
Guys like Anthony should be the validators, not the scientists or computer experts.
“This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs?”
Isn’t that what the story says they did? They noticed the model was wrong by checking measurements on the ground; so they fixed the model.
Jimbo says:
March 22, 2013 at 4:29 am
Cache of historical Arctic sea ice maps discovered
===============
The old nautical charts from England’s golden age of exploration show that sea levels have not risen anything like what is currently believed. These charts are still highly accurate even today, and most of the modern nautical charts are simply copies of these older charts, with corrections for wrecks, rocks missing in the original surveys, and datum adjustments for GPS.
Very few areas worldwide have ever been re-surveyed due to the high cost. Yet, almost universally, if a rock was shown on the charts as awash at low tide 200-300 years ago, it is still awash at low tide today. If sea levels were truly rising, these rocks should no longer be visible at low tide. Nowhere on the charts is a datum adjustment for “sea level rise”.
Which is very strange. These charts are vital to preventing loss of ships and lives. You would think that if sea level rise was real, these charts would have been updated to reflect this.
The reason they have not is quite simple. If the charts were adjusted to show sea levels rising when it has not, then this would result in water depths being reported as deeper than they really are. This would result in ships running aground when they thought they were safe, resulting in the loss of ships and lives.
Thus, nautical charts are one of the best sources of information on sea level rise over the past 2-3 hundred years, and why to this date they have not been used to calibrate sea level rise. Instead we see endless tidal gauges mounted on sand and mud, or sea shells or tea leaves used a proxies.
Am I missing something here? Why would something which is readily observable have to be “modelled”?
The cold weather in Scandinavia has something to do w/the Greenland east coast. Easterly winds from there have been crossing the N Atlantic to hit Greenland. That air isn’t Arctic by that time — not even below freezing.
It’s called weather.
Can some genius at NSIDC please generate an outline of the 1500m contour on Greenland, place it on their anomaly map (Fig 2) and set the color inside the contour to white.
The anomaly map would then appear a tad more honest: showing fictitious anomalies below the surface of the ice is somewhat bizarre to say the least.
This case shows up the folly of overreliance on algorithms, statistics and computer models, and not paying enough attention to real world data.
This was illustrated well with the issue of GHCN temperature adjustments in Iceland. In 1965, Iceland underwent a drastic drop in temperatures. The cold spell lasted well into the 1970’s, and was so severe that agriculture and fishing suffered hugely, leading to mass unemployment and 50% currency devaluation. This time even had a name, “The Sea Ice Years”, and has been well researched by proper scientists.
Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.
There’s more on the background to the Sea Ice Years here.
http://notalotofpeopleknowthat.wordpress.com/2012/10/30/ghcn-temperature-adjustments-in-icelanda-closer-look-at-stykkisholmurpart-ii/
Village Idiot says:
March 21, 2013 at 11:37 pm
(Others as well)
The article says no such thing. It applies to recalibrating 2013 data, not 2012. It even refers to the water from the ice melt of last summer remaining unfrozen under the surface.
Although there are reasons to think that last summers melt was not unprecedented, this article is not one of them.
ps: there is good reason to increase water depth on nautical charts if sea level rise is occurring. Increased water depth opens up new sea-lanes and can save millions in costs. It is not unusual for ships to travel in areas where the difference between a safe passage and running aground is less than the difference between high and low tide for that day.
Paul Homewood says:
March 22, 2013 at 6:53 am
Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.
===========
Very interesting. This shows the problems in adjusting temperatures to try and improve signal quality. What the computer thinks is noise may well be signal, and what the computer this is signal may well be noise.
This is in some way similar to the famous hockey stick, where in an attempt to amplify the signal in tree rings via “calibration” what actually happened was an amplification of noise. Since this noise was random it gave the appearance that temperatures had not changed for 1000 years and we all got the shaft as a result.
jayhd says:
March 22, 2013 at 4:59 am
“. . . actually going to a sampling of sites and getting real data . . .”
Such real data was called ‘ground truth’ and getting such was called “ground truthing.”
I remember it well, much like a beer for 25¢.
http://en.wikipedia.org/wiki/Ground_truth
How lucky do you have to be to find all the ‘mistakes’ work in favour of the ideas your pushing ?
RE: Paul Homewood. Thanks for the link. I like your site.
Now where is Mr. CostCo who was defending NASA’s Greenland ice loss and sea level measurements via satellite (http://wattsupwiththat.com/2012/12/03/why-ice-loss-and-sea-level-measurements-via-satellite-and-the-new-shepard-et-al-paper-are-highly-uncertain-at-the-moment/)
doubting possible issues of unknown errors and unaccounted for drift with remarks like:
“I have technical knowledge in the satellite and instrument domains …”
Mr. CostCo: “Basically you’re insinuating that the glaciological community as a whole does not know how to assess errors and neither does Nature/Science etc”
Wonder what Mr. CostCo would deem failing to properly assess errors that allowed a hosed algorithm involved in measuring Greenland’s Ice Sheets to go undetected until after Shepherd et al paper was touted? Possibly the old ‘Nothing to See Here, Move Along’?
Now why didn’t I read this in my local paper? They carried the unprecedented melting story…
Great story with details on “Glacier Girl” … above comment by Rational Db8 on WWII planes buried in Greenland.
http://www.damninteresting.com/exhuming-the-glacier-girl/
Do we know which glacier was it that the 8 planes landed on?
Is it one of the “fast melting” glaciers listed As Rational noted, if so, how did they get buried in 268 feet of accumulated snow in 50 years?