Support the Arctic Sea Ice Forum and Blog

Author Topic: Permafrost general science thread  (Read 43569 times)

nanning

  • Nilas ice
  • Posts: 2401
  • 0Kg CO₂, 37 KWh/wk,125L H₂O/wk, No offspring
    • View Profile
  • Liked: 304
  • Likes Given: 20397
Re: Permafrost general science thread
« Reply #100 on: June 13, 2020, 05:24:06 PM »
Good post jens imo.

In a global all-lifeforms context:
N₂O is a powerful GHG, then there's also the high-impact threat of large marine methane bursts and in general the likely increasing permafrost emissions in all areas that will be warmed up in an accelerating, step-wise manner because of AGW (BAU).

These permafrost emissions are out of our control!
These emissions will go on. Even when we stop with our anthropogenic emissions. And they are accelerating.

Long term (?) consequences:
A hothouse Earth is coming for certain I think, taking the above in consideration together with all other tipping points. A hyperthermal is likely imo. But that is off-topic here. Sorry, just connecting dots. There are many more dots but I realised that I drifted from the thread topic. Cheers.
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
"It is preoccupation with what other people from your groups think of you, that prevents you from living freely and nobly" - Nanning
Why do you keep accumulating stuff?

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #101 on: June 17, 2020, 06:45:43 AM »
Article about the research in #96:

https://e360.yale.edu/digest/climate-models-underestimate-co2-emissions-from-permafrost-by-14-percent-study-finds

Scientists estimate there are about 1,500 billion metric tons of carbon locked away in Arctic permafrost, and that 5 to 15 percent of this carbon could be emitted as carbon dioxide by 2100 — enough to increase global temperatures 0.3 to 0.4 degrees Celsius. But these estimates do not include the CO2 that forms when permafrost carbon escapes into Arctic lakes and rivers and is oxidized by ultraviolet and visible light, a process known as photomineralization.

Researchers at the University of Michigan studied organic carbon from six different Arctic locations and found that substantial carbon dioxide emissions could be released through photomineralization — enough to raise permafrost-related CO2 emissions by 14 percent.
...
“Only recently have global climate models included greenhouse gases from thawing permafrost soils. But none of them contain this feedback pathway,”

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

vox_mundi

  • Young ice
  • Posts: 4354
    • View Profile
  • Liked: 2471
  • Likes Given: 334
Re: Permafrost general science thread
« Reply #102 on: July 01, 2020, 03:09:45 AM »
Beavers Gnawing Away at the Arctic Permafrost
https://phys.org/news/2020-06-beavers-gnawing-arctic-permafrost.html

Alaska's beavers are profiting from climate change, and spreading rapidly. In just a few years' time, they have not only expanded into many tundra regions where they'd never been seen before; they're also building more and more dams in their new homes, creating a host of new water bodies. This could accelerate the thawing of the permafrost soils, and therefore intensify climate change, as an International American-German research team reports in the journal Environmental Research Letters.


The upper two images are photos taken within the study area in 2016 showing the tundra region setting. The bottom two images are taken from similar tundra across Hotham Inlet in 2015 (lower left) and 2011 (lower right) showing beaver dams in a drained lake basin outlet and along a beaded stream course, respectively.

... Back in 2018, Ingmar Nitze and Guido Grosse from the AWI, together with colleagues from the U.S., determined that the beavers living in an 18,000-square-kilometer section of northwest Alaska had created 56 new lakes in just five years. For their new study, the team from the AWI, the University of Alaska in Fairbanks, and the University of Minnesota in Minneapolis have now taken a closer look at this trend. Using detailed satellite data and extended time series, the experts tracked the beavers' activities in two other regions in Alaska—and were surprised by what they found.

"Of course, we knew that the beavers there had spread substantially over the last few decades," says Nitze. This is partly due to climate change; thanks to rising temperatures, now more and more habitats offer the shrubs that the animals need for food and building material. Furthermore, the lakes, which used to freeze solid, now offer beaver-friendlier conditions, thanks to their thinner seasonal winter ice cover. Lastly, the rodents aren't hunted as intensively as in the past. As a result, it's a good time to be a beaver in the Arctic.

"But we never would have dreamed they would seize the opportunity so intensively," says Nitze. The high-resolution satellite images of the roughly 100-square-kilometer study area near the town of Kotzebue reveal the scale of the animals' activities there. From just two dams in 2002, the number had risen to 98 by 2019—a 5,000-percent increase, with more than 5 new dams being constructed per year. And the larger area surveyed, which covers the entire northern Baldwin Peninsula, also experienced a beaver dam boom. According to Nitze, "We're seeing exponential growth there. The number of these structures doubles roughly every four years."

This has already affected the water balance. Apparently, the rodents intentionally do their work in those parts of the landscape that they can most easily flood. To do so, sometimes they dam up small streams, and sometimes the outlets of existing lakes, which expand as a result. "But they especially prefer drained lake basins," Benjamin Jones, lead author of the study, and Nitze report. In many cases, the bottoms of these former lakes are prime locations for beaver activity. "The animals have intuitively found that damming the outlet drainage channels at the sites of former lakes is an efficient way to create habitat. So a new lake is formed which degrades ice-rich permafrost in the basin, adding to the effect of increasing the depth of the engineered waterbody," added Jones. These actions have their consequences: in the course of the 17-year timeframe studied, the overall water area in the Kotzebue region grew by 8.3 percent. And roughly two-thirds of that growth was due to the beavers.

The researchers suspect that there have been similar construction booms in other regions of the Arctic; accordingly, they now want to expand their 'beaver manhunt' across the Arctic. "The growth in Canada, for example, is most likely even more extreme," says Nitze. And each additional lake thaws the permafrost below it and on its banks. Granted, the frozen soil could theoretically bounce back after a few years, when the beaver dams break; but whether or not the conditions will be sufficiently cold for that to happen is anyone's guess.


Mapping beaver dams in high-resolution satellite imagery available for the northern Baldwin Peninsula, Alaska. The location of individual dams indicated with red arrow and the flow direction with a light blue arrow. (a) A series of four dams at the outlet of a lake, (b) a ~60 m long dam built in a drained lake basin, (c) a series of dams at the outlet of a lake near a confluence with a beaded stream, (d) a series of dams in a channel running through the middle of a drained lake basin, (e) five dams progressing down the outlet channel of a thermokarst lake, and (f) a series of dams in a beaded stream gulch. Examples shown here taken from 2019 images; note differences in scale across image frames. All dams were constructed after 2002.

Benjamin M. Jones et al, Increase in beaver dams controls surface water and thermokarst dynamics in an Arctic tundra region, Baldwin Peninsula, northwestern Alaska, Environmental Research Letters (2020).
https://iopscience.iop.org/article/10.1088/1748-9326/ab80f1
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

vox_mundi

  • Young ice
  • Posts: 4354
    • View Profile
  • Liked: 2471
  • Likes Given: 334
Re: Permafrost general science thread
« Reply #103 on: July 20, 2020, 10:20:19 PM »
40 More Gt of CO2 Baked In: Plant Roots Increase Carbon Emission from Permafrost Soils
https://phys.org/news/2020-07-roots-carbon-emission-permafrost-soils.html

Plant roots in soil stimulate microbial decomposition, a mechanism called the priming effect. An international research team co-lead by Frida Keuper from INRAE and Umeå University and Birgit Wild from Stockholm University shows that the priming effect alone can cause emission of 40 billion tons carbon from permafrost by 2100. The study was published today in Nature Geoscience.

Scientists have previously anticipated that rapidly rising temperatures will drive the emission of 50-100 billion ton permafrost carbon by 2100. On top of that, plant roots feed sugar to the microorganisms in the soil, which the microbes can use to break down more soil organic matter—the priming effect—resulting in even higher greenhouse gas emissions.

The researchers combined maps of plant activity and data on soil carbon content from the Northern Circumpolar Soil Carbon Database with an extensive literature survey on priming and plant root properties, to estimate the priming effect in permafrost ecosystems and its influence on greenhouse gas emissions.

They show that the priming effect increases soil microbial respiration by 12 percent, which causes the additional loss of 40 billion tons of carbon by 2100 compared to current predictions for permafrost. This equals almost a quarter of the remaining "carbon budget" for human activities to limit global warming to max 1.5°C.

Carbon loss from northern circumpolar permafrost soils amplified by rhizosphere priming, Nature Geoscience (2020).
https://www.nature.com/articles/s41561-020-0607-0
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

vox_mundi

  • Young ice
  • Posts: 4354
    • View Profile
  • Liked: 2471
  • Likes Given: 334
Re: Permafrost general science thread
« Reply #104 on: July 25, 2020, 02:53:37 AM »
Alaska Is Getting Wetter. That's Bad News for Permafrost and the Climate
https://phys.org/news/2020-07-alaska-wetter-bad-news-permafrost.html

Alaska is getting wetter. A new study spells out what that means for the permafrost that underlies about 85% of the state, and the consequences for Earth's global climate.

The study, published today in Nature Publishing Group journal Climate and Atmospheric Science, is the first to compare how rainfall is affecting permafrost thaw across time, space, and a variety of ecosystems. It shows that increased summer rainfall is degrading permafrost across the state.

As Siberia remains in the headlines for record-setting heat waves and wildfires, Alaska is experiencing the rainiest five years in its century-long meteorological record. Extreme weather on both ends of the spectrum—hot and dry versus cool and wet—are driven by an aspect of climate change called Arctic amplification.
"In our research area the winter has lost almost three weeks to summer," says study lead author and Fairbanks resident Thomas A. Douglas, who is a scientist with the U.S. Army Cold Regions Research and Engineering Laboratory. "This, along with more rainstorms, means far more wet precipitation is falling every summer."

Over the course of five years, the research team took 2750 measurements of how far below the land's surface permafrost had thawed by the end of summer across a wide range of environments near Fairbanks, Alaska. The five-year period included two summers with average precipitation, one that was a little drier than usual, and the top and third wettest summers on record. Differences in annual rainfall were clearly imprinted in the amount of permafrost thaw.

More rainfall led to deeper thaw across all sites. After the wettest summer in 2014, permafrost didn't freeze back to previous levels even after subsequent summers were drier. Wetlands and disturbed sites, like trail crossings and clearings, showed the most thaw. Tussock tundra, with its deep soils and covering of tufted grasses, has been found to provide the most ecosystem protection of permafrost. While permafrost was frozen closest to the surface in tussock tundra, it experienced the greatest relative increase in the depth of thaw in response to rainfall, possibly because water could pool on the flat surface. Forests, especially spruce forests with thick sphagnum moss layers, were the most resistant to permafrost thaw. Charlie Koven, an Earth system modeler with the Lawrence Berkeley National Laboratory, used the field measurements to build a heat balance model that allowed the team to better understand how rain was driving heat down into the permafrost ground.


Relationships between active layer depth and summer precipitation.

Thomas A. Douglas et al, Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems, npj Climate and Atmospheric Science (2020)
https://www.nature.com/articles/s41612-020-0130-4
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #105 on: July 25, 2020, 07:46:42 AM »
Experiments Reveal How Permafrost Carbon Becomes Carbon Dioxide

Field samples from Alaska show how sunlight and iron convert permafrost carbon to carbon dioxide. Climate models ignore this process.

...

Researchers have now experimentally studied how sunlight triggers carbon dioxide production from permafrost carbon that’s been flushed to lakes and rivers, a process long ignored in climate models.

Current estimates of global warming from permafrost carbon feedback are biased low, the team concluded.

...

Microbes and Sunlight
One way in which permafrost carbon gets converted to carbon dioxide is via microbes—some microscopic life-forms chow down on carbon and respire carbon dioxide.

Although this microbial process is generally taken into account in climate models, comparably little is known about the permafrost carbon that’s flushed to lakes and rivers, where it’s exposed to sunlight. “We’ve known for a while that sunlight converts organic carbon to carbon dioxide, but the governing control of this process has escaped us,” said Ward.

It’s been hypothesized that this photomineralization might be controlled by the presence of iron, which is abundant in Arctic fresh waters. “There have been lots of lab-based studies suggesting that iron is a key player, but this is the first to let nature tell us what controls this process,” said Ward.

In 2018, Ward and his colleagues collected five samples of permafrost from northern Alaska. Back in the laboratory, they thawed the permafrost, filtered out the microbes, and isolated the dissolved organic carbon and other constituents, including iron. They then exposed the samples to different wavelengths of ultraviolet and visible light.

Visible Light Wins
In nature, the highest rates of photomineralization occur in the presence of visible light, Ward and his colleagues calculated. Two factors contribute to this finding. First, Earth’s surface receives significantly more visible light than ultraviolet light. Second, iron kick-starts reactions at longer wavelengths, the team showed. (Visible light is characterized by longer wavelengths than ultraviolet light.)

Photomineralization’s wavelength dependence has important implications, said Ward. It means that permafrost carbon in deep lakes or rivers is still apt to be converted to carbon dioxide. “As you move deeper into the water column, there’s less ultraviolet light available and more visible light,” said Ward.

Older and More Effective
The researchers also determined that the older carbon found in permafrost—several thousand years old—was roughly twice as effective at producing carbon dioxide as modern carbon. Modern carbon has more sunlight-absorbing compounds, said team member Jenny Bowen, a biogeochemist at the University of Michigan, but permafrost carbon is better at reaping the reaction-promoting benefits of iron.

This unaccounted-for contribution from old carbon has the potential to fundamentally change the carbon cycle, said Ted Schuur, an ecosystem ecologist at Northern Arizona University in Flagstaff not involved in the research. “Stuff that wasn’t part of the atmosphere is suddenly ending up in the atmosphere.”
Since photomineralization of permafrost carbon isn’t presently included in climate models, estimates of future global warming are biased low, the researchers concluded. “Sunlight increases the amount of carbon dioxide coming from thawing permafrost by 14%,” said Bowen. “The planet will warm even more than expected.”

These results were published last month in Geophysical Research Letters.

...

https://eos.org/articles/experiments-reveal-how-permafrost-carbon-becomes-carbon-dioxide



Arctic Amplification of Global Warming Strengthened by Sunlight Oxidation of Permafrost Carbon to CO2

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL087085

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

blumenkraft

  • Guest
Re: Permafrost general science thread
« Reply #106 on: August 11, 2020, 03:02:10 PM »
Anthrax Outbreak In Russia Thought To Be Result Of Thawing Permafrost

Quote
Russia is fighting a mysterious anthrax outbreak in a remote corner of Siberia. Dozens of people have been hospitalized; one child has died. The government airlifted some families out because more than 2,000 reindeer have been infected.

Link >> https://www.npr.org/sections/goatsandsoda/2016/08/03/488400947/anthrax-outbreak-in-russia-thought-to-be-result-of-thawing-permafrost

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #107 on: August 12, 2020, 12:26:45 PM »
Climate change: Warming world will be 'devastating' for frozen peatlands

The world's peatlands will become a large source of greenhouse gases as temperatures rise this century, say scientists.

Right now, huge amounts of carbon are stored in boggy, often frozen regions stretching across northern parts of the world.

But much of the permanently frozen land will thaw this century, say experts.

This will release warming gases at a rate that could be 30-50% greater than previous estimates.

Using data compiled from more than 7,000 field observations, the authors of this new study were able to generate the most accurate maps to date of the peatlands, their depth and the amount of warming gases they contain.

They show that the boggy terrain covers 3.7 million sq kilometres (1.42 million sq miles).

...

"But my best estimate is that this shift will occur in the second half of this century."

....

If this new peatland estimate is included with all the estimates for permafrost melting, it is projected to equal the annual emissions of the EU and UK by 2100.

"The only way to limit the permafrost carbon feedback is to reduce global warming," said Dr Hugelius.

https://www.bbc.com/news/science-environment-53726487

So this is both permafrost and non permafrost peatlands combined. That of course does not matter for the planet.

Large stocks of peatland carbon and nitrogen are
vulnerable to permafrost thaw
https://www.pnas.org/content/pnas/early/2020/08/04/1916387117.full.pdf
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

morganism

  • Frazil ice
  • Posts: 255
    • View Profile
  • Liked: 53
  • Likes Given: 1
Re: Permafrost general science thread
« Reply #108 on: August 22, 2020, 07:13:48 PM »
Electric mud’ teems with new, mysterious bacteria

"The bacteria also alter the mud’s chemistry, making layers closer to the surface more alkaline and deeper layers more acidic, Malkin has found. Such pH gradients can affect “numerous geochemical cycles,” she says, including those involving arsenic, manganese, and iron, creating opportunities for other microbes.

With vast swaths of the planet covered by mud, cable and nanowire bacteria are likely having an influence on global climate, researchers say. Nanowire bacteria, for example, can strip electrons from organic materials, such as dead diatoms, then shuttle them to other bacteria that produce methane—a potent greenhouse gas. Under different circumstances, cable bacteria can reduce methane production.

https://www.sciencemag.org/news/2020/08/electric-mud-teems-new-mysterious-bacteria


BornFromTheVoid

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 578
  • Likes Given: 199
Re: Permafrost general science thread
« Reply #109 on: August 27, 2020, 11:45:35 AM »
New paper is available now, feel free to ask any question about it.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087917

Abstract
High overall rates of permafrost cliff retreat, coupled with spatial variability, have been accompanied by increased uncertainty over future landscape dynamics. We map long‐term (>80 years) retreat of the shoreline and photogrammetrically analyze historic aerial imagery to quantify the processes at a permafrost coast site with massive ground ice. Retreat rates have been relatively constant but topographic changes show that subsidence is a potentially critical but often ignored component of coastal sensitivity, exceeding landward recession by over 3 times during the last 24 years. We calibrate novel passive seismic surveys along clear and variable exposures of massive ground ice and then spatially map key sub‐surface layers. Combining decadal patterns of volumetric change with new ground ice variation maps enables past trends to be interpreted, future volumetric geomorphic behavior to be better constrained, and improves the assessment of permafrost coast sensitivity and the release of carbon‐bearing material.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Tor Bejnar

  • Young ice
  • Posts: 3717
    • View Profile
  • Liked: 650
  • Likes Given: 435
Re: Permafrost general science thread
« Reply #110 on: August 27, 2020, 05:39:26 PM »
I wasn't familiar with the term "ground ice", so I looked it up on the inter-tubey thing:
From Glossary of Permafrost and Related Ground-Ice Terms (a PDF)
Quote
ice, ground (see also ice, buried; ice, epigenetic; ice, intrusive; ice,
syngenetic)
[glace de sol]
A general term referring to all types of ice formed in freezing and frozen
ground(see Figure 10).
COMMENT: Ground ice occurs in pores, cavities, voids or other
openings in soil or rock and includes massiveice, but generally excludes
buriedice. Ground ice may be epigenetic or syngenetic,
contemporaneous or relict, aggrading or degrading, perennial or
seasonal. It may occur as lenses, wedges, veins, sheets, seams, irregular
masses, or as individual crystals or coatings on mineral or organic
particles. Perennial ground ice can only occur within permafrost bodies.
REFERENCES: Mackay, 1972b; Pollard and French, 1980.

So (from reading the plain language offering), when climate warms, permafrost melts.  A couple things happen:
  • what was once hard (frozen hard) is now soft and erodible
  • what was once frozen H2O in the ground is now liquid and it flows away, causing the surface to 'slump' (locally or widespread)
Arctic ice is healthy for children and other living things.

longwalks1

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 51
  • Likes Given: 12
Re: Permafrost general science thread
« Reply #111 on: August 27, 2020, 06:38:08 PM »
A short quote from BFV #109 post for  https://doi.org/10.1029/2020GL087917        Massive Ice Control on Permafrost Coast Erosion and Sensitivity

Quote
2.Regional Setting and Methods The Tuktoyaktuk Coastlands, northwest Canada,arelocated within the southern Beaufort Sea area  and aredominated  by  ice-rich permafrost landscapes(Rampton,  1988).  Thisgenerally flat, deltaiclandscape is punctuated by ice cored plateaus and domes acrossthe tundra. Here, we focus on Peninsula Point(Figure 1a), 6 km southwest of Tuktoyaktukandwithin the Pingo Canadian Landmark (a national historic site managed by Parks Canada), itis a representative type-site  for  intrasedimental  massive  ice (Gilbert  et  al.,  2016;  Mackay  &  Dallimore,  1992; Murton,  2009). Compoundingthe dynamic  erosion  processesin  the  area (Murton,  2005), reduced sea-ice (Overeem et al., 2011)and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013)and a relative 2.5 mm a-1sea-level rise (Hill et al., 1993)have intensified the degradation of permafrost coasts in the region

Passive seismic surveys, nicer to the larger fauna, the caribou need all the TLC that they can get.   

Quote
3.2Mapping subsurface structure of massive iceThis work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.

Just a stellar usage of old data and new right sized technology. 

Just west of Tuktoyatuk.  About 30 - 35 km east of the McKenzie.  Quick background of the scene at
https://en.wikipedia.org/wiki/Pingo_National_Landmark

BornFromTheVoid

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 578
  • Likes Given: 199
Re: Permafrost general science thread
« Reply #112 on: August 27, 2020, 08:40:14 PM »
I wasn't familiar with the term "ground ice", so I looked it up on the inter-tubey thing:
From Glossary of Permafrost and Related Ground-Ice Terms (a PDF)
Quote
ice, ground (see also ice, buried; ice, epigenetic; ice, intrusive; ice,
syngenetic)
[glace de sol]
A general term referring to all types of ice formed in freezing and frozen
ground(see Figure 10).
COMMENT: Ground ice occurs in pores, cavities, voids or other
openings in soil or rock and includes massiveice, but generally excludes
buriedice. Ground ice may be epigenetic or syngenetic,
contemporaneous or relict, aggrading or degrading, perennial or
seasonal. It may occur as lenses, wedges, veins, sheets, seams, irregular
masses, or as individual crystals or coatings on mineral or organic
particles. Perennial ground ice can only occur within permafrost bodies.
REFERENCES: Mackay, 1972b; Pollard and French, 1980.

So (from reading the plain language offering), when climate warms, permafrost melts.  A couple things happen:
  • what was once hard (frozen hard) is now soft and erodible
  • what was once frozen H2O in the ground is now liquid and it flows away, causing the surface to 'slump' (locally or widespread)

We were dealing with a site that was specifically know for its massive ice bodies. These are thick  layers, up to 10s of meters, covered by permafrost and usually with permafrost below them too.

Here's an example from the field site, with the SfM models we used too.


We examined the erosion process called retrogressive thaw slumps. Where cliffs form over these massive ice bodies and spread inland really quickly. They can cause so much material to flow towards the shoreline that it results in large mud lobes causing transient progradation, like the lobe in the pic above. This means you get mass loss through vertical changes in the landscape several times faster than from shoreline retreat
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

BornFromTheVoid

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 578
  • Likes Given: 199
Re: Permafrost general science thread
« Reply #113 on: August 27, 2020, 08:44:21 PM »
A short quote from BFV #109 post for  https://doi.org/10.1029/2020GL087917        Massive Ice Control on Permafrost Coast Erosion and Sensitivity

Quote
2.Regional Setting and Methods The Tuktoyaktuk Coastlands, northwest Canada,arelocated within the southern Beaufort Sea area  and aredominated  by  ice-rich permafrost landscapes(Rampton,  1988).  Thisgenerally flat, deltaiclandscape is punctuated by ice cored plateaus and domes acrossthe tundra. Here, we focus on Peninsula Point(Figure 1a), 6 km southwest of Tuktoyaktukandwithin the Pingo Canadian Landmark (a national historic site managed by Parks Canada), itis a representative type-site  for  intrasedimental  massive  ice (Gilbert  et  al.,  2016;  Mackay  &  Dallimore,  1992; Murton,  2009). Compoundingthe dynamic  erosion  processesin  the  area (Murton,  2005), reduced sea-ice (Overeem et al., 2011)and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013)and a relative 2.5 mm a-1sea-level rise (Hill et al., 1993)have intensified the degradation of permafrost coasts in the region

Passive seismic surveys, nicer to the larger fauna, the caribou need all the TLC that they can get.   

Quote
3.2Mapping subsurface structure of massive iceThis work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.

Just a stellar usage of old data and new right sized technology. 

Just west of Tuktoyatuk.  About 30 - 35 km east of the McKenzie.  Quick background of the scene at
https://en.wikipedia.org/wiki/Pingo_National_Landmark

Cheers!
The combination of the passive seismics with the cm scale surface models generated from drone imagery meant we could create 3D models of sections of the site too. That way we can figure out how much of the ground is soil vs ice. This matters for how fast it will erode, the mechanism by which it will erode, and knowing the constituents (ice vs soil) we can better constrain the volume of carbon that will be released too.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Tor Bejnar

  • Young ice
  • Posts: 3717
    • View Profile
  • Liked: 650
  • Likes Given: 435
Re: Permafrost general science thread
« Reply #114 on: August 27, 2020, 08:46:49 PM »
cleaned up quotes (without actual access to paper):
Quote
    2. Regional Setting and Methods.  The Tuktoyaktuk Coastlands, northwest Canada, are located within the southern Beaufort Sea area and are dominated by ice-rich permafrost landscapes (Rampton, 1988).  This generally flat, deltaic landscape is punctuated by ice cored plateaus and domes across the tundra.  Here, we focus on Peninsula Point (Figure 1a), 6 km southwest of Tuktoyaktuk and within the Pingo Canadian Landmark (a national historic site managed by Parks Canada), it is a representative type-site  for  intrasedimental massive ice (Gilbert et al., 2016; Mackay & Dallimore, 1992; Murton, 2009). Compounding the dynamic erosion processes in  the area (Murton, 2005), reduced sea-ice (Overeem et al., 2011) and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013) and a relative 2.5 mm a-1 sea-level rise (Hill et al., 1993) have intensified the degradation of permafrost coasts in the region.




    3.2 Mapping subsurface structure of massive ice.  This work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.
Arctic ice is healthy for children and other living things.

Tor Bejnar

  • Young ice
  • Posts: 3717
    • View Profile
  • Liked: 650
  • Likes Given: 435
Re: Permafrost general science thread
« Reply #115 on: August 27, 2020, 09:24:13 PM »
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 

I wasn't aware of how thick 'pure' ice could be within the permafrost.  At first (just now) I wondered how 'lenses' grew so thick, but then imagined a (10s-to-100s-of-centuries long) series of freeze/thaw [just above the ice] cycles could built up the ice layer to basically any thickness.  (I don't presume to understand the actual physics ... and my imagination is just my imagination.) 

Wow!  'Wouldn't want to be walking around that area on the wrong day!

A neighbor in New Hampshire, one Summer, paved his long-used mostly dirt driveway, and the next Spring (Mud Season) his pickup truck (well, one wheel) fell through the pavement up to its axle.  Solid ground really can become "quicksand". 
Arctic ice is healthy for children and other living things.

BornFromTheVoid

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 578
  • Likes Given: 199
Re: Permafrost general science thread
« Reply #116 on: August 27, 2020, 10:27:58 PM »
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 

I wasn't aware of how thick 'pure' ice could be within the permafrost.  At first (just now) I wondered how 'lenses' grew so thick, but then imagined a (10s-to-100s-of-centuries long) series of freeze/thaw [just above the ice] cycles could built up the ice layer to basically any thickness.  (I don't presume to understand the actual physics ... and my imagination is just my imagination.) 

Wow!  'Wouldn't want to be walking around that area on the wrong day!

A neighbor in New Hampshire, one Summer, paved his long-used mostly dirt driveway, and the next Spring (Mud Season) his pickup truck (well, one wheel) fell through the pavement up to its axle.  Solid ground really can become "quicksand".

The one on Peninsula Point formed as the Laurentide ice sheet was retreating, so the ground was freezing but there was loads of subsurface meltwater flowing and freezing too. it may have been up to 20 m thick at one stage.

The number and growth of thaw slumps are crazy. This study from the nearby Banks Island, showing a 60 fold increase in their numbers since the mid 80s

https://www.nature.com/articles/s41467-019-09314-7

I have some cool pics and animation of the slumps too. I'll post them up tomorrow if I get the time. You can literally watch them developing just standing there.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Sebastian Jones

  • Frazil ice
  • Posts: 426
    • View Profile
  • Liked: 107
  • Likes Given: 98
Re: Permafrost general science thread
« Reply #117 on: August 28, 2020, 12:22:59 AM »
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 
........................


The one on Peninsula Point formed as the Laurentide ice sheet was retreating, so the ground was freezing but there was loads of subsurface meltwater flowing and freezing too. it may have been up to 20 m thick at one stage.

The number and growth of thaw slumps are crazy. This study from the nearby Banks Island, showing a 60 fold increase in their numbers since the mid 80s

https://www.nature.com/articles/s41467-019-09314-7

I have some cool pics and animation of the slumps too. I'll post them up tomorrow if I get the time. You can literally watch them developing just standing there.

We have a community science thaw slump monitoring project on the Dempster Highway- the road that leads (most of the way) to BFTV's study area.
I'd love to read the entire paper, is there a way to get it out from behind the paywall? SciHub does not have it yet.

gerontocrat

  • First-year ice
  • Posts: 9587
    • View Profile
  • Liked: 3803
  • Likes Given: 29
Re: Permafrost general science thread
« Reply #118 on: October 02, 2020, 09:38:35 PM »
This one is about the cascading effects of permafrost thaw on slopes - in NW Canada, but must be applicable over all the permafrosted tundra.

Quote
Short summary
We address knowledge gaps in the understanding the climate-driven amplification of slope thermokarst, the evolution of downstream linkages, and the cascade of consequences. The non-linear intensification of thaw-driven landslides in glaciated permafrost terrain of northwestern Canada has strengthened slope to stream connectivity. Primary effects to headwater systems indicate the major potential for long-term impacts and their propagation across watershed scales to coastal environments.
https://tc.copernicus.org/preprints/tc-2020-218/tc-2020-218.pdf
Permafrost thaw couples slopes with downstream systems and effects propagate through Arctic drainage networks
Quote
Abstract.
The intensification of thaw-driven mass wasting is transforming glacially-conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Within the context of recent, rapidly evolving climate controls on the geomorphology of permafrost terrain we:
A) quantify three-dimensional slump enlargement and described the processes and thresholds coupling slopes to downstream systems;
B) investigate catchment-scale patterns of slope thermokarst (thaw slumps and slides) impacts and the geomorphic implications; and
C) project the propagation of effects through hydrological networks draining continuous permafrost of northwestern Canada.

Power-law relationships between thaw-slump area and volume (R2 = 0.90), and thickness of permafrost thawed (R2 = 0.63), combined with the multi-decadal (1985–2018) increase in areal extent of thaw-slump disturbance show a two-order of magnitude increase in catchment-scale geomorphic activity and the coupling of slope and hydrological systems.

Predominant catchment effects are to first- and second-order streams where sediment delivery commonly exceeds stream transport capacity by orders of magnitude indicating millennial-scale perturbation of downstream systems. Assessment of hydrological networks indicates thaw-driven mass wasting directly affects over 6,760 km of stream segments, 890 km of coastline, and 1,370 lakes in the 994,860 km2 study area.

Downstream propagation of slope thermokarst indicates a potential increase in the number of affected lakes by at least a factor of 4 (n > 5,600), impacted stream length by a factor of 7 (> 48,000 km) and defines several major impact zones to lakes, deltas, and coastal areas. Prince of Wales Strait is the receiving marine environment for greatly increased sediment and geochemical fluxes from numerous slump impacted hydrological networks draining the landmasses of Banks and Victoria Islands. Peel and Mackenzie Rivers are globally significant conveyors of the slope thermokarst cascade delivering effects to North America’s largest Delta and the Beaufort Sea.

Climate-driven erosion of ice-rich slopes in permafrost preserved glaciated terrain has triggered a time-transient cascade of downstream effects that signal the renewal of post-glacial landscape evolution. Glacial legacy and the patterns of continental drainage dictate that terrestrial, freshwater and marine environments of western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia.
"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)

longwalks1

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 51
  • Likes Given: 12
Re: Permafrost general science thread
« Reply #119 on: October 03, 2020, 03:01:47 AM »
I just went straight to the article. The phrases "non-linear increase",   "2 order of magnitude increase",   just jumped out at me.  Going back to the summation I see you italicized those.      I await comment from BTFV and others over the article especially  the Tuktoyaktuk  Coastland  implications.  Wow.   

icefisher

  • New ice
  • Posts: 51
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: Permafrost general science thread
« Reply #120 on: October 04, 2020, 01:20:44 AM »
"Permafrost is melting from the top-down and bottom-up."  Response of Vladimir Romanovsky Professor at International Arctic Research Center, Fairbanks Alaska; to a question from Elizabeth Kolbert in her 2006 book "Field Notes from a Catastrophe".  Professor Romanovsky installed a series of temperature gauges in boreholes across a section of Alaskan permafrost.  He's been studying Alaskan permafrost for at least 20 years. Haven't had time to catch up on his publications. He can be reached at veromanovsky@alaska.edu. 

vox_mundi

  • Young ice
  • Posts: 4354
    • View Profile
  • Liked: 2471
  • Likes Given: 334
Re: Permafrost general science thread
« Reply #121 on: October 16, 2020, 09:49:46 PM »
Arctic Ocean Sediments Reveal Permafrost Thawing During Past Climate Warming
https://phys.org/news/2020-10-arctic-ocean-sediments-reveal-permafrost.html

Sea floor sediments of the Arctic Ocean can help scientists understand how permafrost responds to climate warming. A multidisciplinary team from Stockholm University has found evidence of past permafrost thawing during climate warming events at the end of the last ice age. Their findings, published in Science Advances, caution about what could happen in the near future: That Arctic warming by only a few degrees Celsius may trigger massive permafrost thawing, coastal erosion, and the release of the greenhouse gases carbon dioxide (CO2) and methane (CH4) into the atmosphere.

... "Our new study shows for the first time the full history of how warming at the end of the last ice age triggered permafrost thawing in Siberia. This also suggests the release of large quantities of greenhouse gases," says Jannik Martens, Ph.D. student at Stockholm University and lead author of the study. "It appears likely that past permafrost thawing at times of climate warming, about 14,700 and 11,700 years ago, was in part also related to the increase in CO2 concentrations that is seen in Antarctic ice cores for these times. It seems that Arctic warming by only a few degrees Celsius is sufficient to disturb large areas covered by permafrost and potentially affect the climate system."

In the current study, the scientists used an eight meters long sediment core that was recovered from the sea floor more than 1 000 meters below the surface of the Arctic Ocean during the SWERUS-C3 expedition onboard the Swedish icebreaker Oden back in 2014. To reconstruct permafrost thawing on land, the scientists applied radiocarbon (14C) dating and molecular analysis to trace organic remains that once were released by thawing permafrost and then washed into the Arctic Ocean.

"From this core we also learned that erosion of permafrost coastlines was an important driving force for permafrost destruction at the end of the last ice age. Coastal erosion continues to the present day, though ten times slower than during these earlier rapid warming period. With the recent warming trends, however, we see again an acceleration of coastal erosion in some parts of the Arctic, which is expected to release greenhouse gases by degradation of the released organic matter," says Örjan Gustafsson, Professor at Stockholm University and leader of the research program. "Any release from thawing permafrost mean that there is even less room for anthropogenic greenhouse gas release in the earth-climate system budget before dangerous thresholds are reached.

Gustafsson, Martens and their colleagues are now again in the Arctic Ocean as part of the International Siberian Shelf Study (ISSS-2020) onboard the Russian research vessel Akademik Keldysh. The expedition left the port of Arkhangelsk on September 26 and is currently in the East Siberian Sea, seeking more answers to how changing climate may trigger release of carbon, including greenhouse gases, from Arctic permafrost systems, including coastal erosion and permafrost below the sea bottom preserved from the past ice age.



Remobilization of dormant carbon from Siberian-Arctic permafrost during three past warming events. Sci. Adv. 6, eabb6546 (2020)
https://advances.sciencemag.org/content/6/42/eabb6546



... This demonstrates that Arctic warming by only a few degrees may suffice to abruptly activate large-scale permafrost thawing, indicating a sensitive trigger for a threshold-like permafrost climate change feedback.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

gerontocrat

  • First-year ice
  • Posts: 9587
    • View Profile
  • Liked: 3803
  • Likes Given: 29
Re: Permafrost general science thread
« Reply #122 on: October 18, 2020, 01:59:09 PM »
I didn't expect Tsunamis to be a permafrost melting consequence that is becoming a probability rather than a possibility.

https://www.theguardian.com/environment/2020/oct/18/alaska-climate-change-tsunamis-melting-permafrost
Alaska's new climate threat: tsunamis linked to melting permafrost
Quote
In Alaska and other high, cold places around the world, new research shows that mountains are collapsing as the permafrost that holds them together melts, threatening tsunamis if they fall into the sea.

Scientists are warning that populated areas and major tourist attractions are at risk.

One area of concern is a slope of the Barry Arm fjord in Alaska that overlooks a popular cruise ship route.

The Barry Arm slide began creeping early last century, sped up a decade ago, and was discovered this year using satellite photos. If it lets loose, the wave could hit any ships in the area and reach hundreds of meters up nearby mountains, swamping the popular tourist destination and crashing as high as 10 meters over the town of Whittier. Earlier this year, 14 geologists warned that a major slide was “possible” within a year, and “likely” within 20 years.

In 2015, a similar landslide, on a slope that had also crept for decades, created a tsunami that sheared off forests 193 meters up the slopes of Alaska’s Taan Fiord.

“When the climate changes,” said geologist Bretwood Higman, who has worked on Taan Fiord and Barry Arm, “the landscape takes time to adjust. If a glacier retreats really quickly it can catch the surrounding slopes by surprise – they might fail catastrophically instead of gradually adjusting.”

After examining 30 years of satellite photos, for instance, geologist Erin Bessette-Kirton has found that landslides in Alaska’s St Elias mountains and Glacier Bay correspond with the warmest years.

Warming clearly leads to slides, but knowing just when those slides will release is a much harder problem. “We don’t have a good handle on the mechanism,” Bessette-Kirkton said. “We have correlations, but we don’t know the driving force. What conditions the landslide, and what triggers it?”

Adding to the problem, global heating has opened up water for landslides to fall in. A recent paper by Dan Shugar, a geomorphologist at the University of Calgary, shows that as glaciers have shrunk, glacial lakes have grown, ballooning 50% in both number and size in 18 years. In the ocean, fjords lengthen as ice retreats. Slopes that used to hang over ice now hang over water.

Over the past century, 10 of the 14 tallest tsunamis recorded happened in glaciated mountain areas. In 1958, a landslide into Alaska’s Lituya Bay created a 524-meter wave – the tallest ever recorded. In Alaska’s 1964 earthquake, most deaths were from tsunamis set off by underwater landslides.

To deal with the hazard, experts hope to predict when a slope is more likely to fail by installing sensors on the most dangerous slopes to measure the barely perceptible acceleration of creeping that may presage a slide.
"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)

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #123 on: October 26, 2020, 01:24:12 PM »
The linked reference uses new paleo-findings to indicate that the risk of an abrupt remobilization of dormant carbon in the Siberian-Arctic permafrost is higher than previously assumed by consensus climate scientists.  This is particularly true if abrupt sea level rise floods coastal Arctic permafrost regions in coming decades:

Jannik Martens et al (16 Oct 2020), "Remobilization of dormant carbon from Siberian-Arctic permafrost during three past warming events", Science Advances, Vol. 6, no. 42, eabb6546, DOI: 10.1126/sciadv.abb6546

https://advances.sciencemag.org/content/6/42/eabb6546

Abstract
Carbon cycle models suggest that past warming events in the Arctic may have caused large-scale permafrost thaw and carbon remobilization, thus affecting atmospheric CO2 levels. However, observational records are sparse, preventing spatially extensive and time-continuous reconstructions of permafrost carbon release during the late Pleistocene and early Holocene. Using carbon isotopes and biomarkers, we demonstrate that the three most recent warming events recorded in Greenland ice cores—(i) Dansgaard-Oeschger event 3 (~28 ka B.P.), (ii) Bølling-Allerød (14.7 to 12.9 ka B.P.), and (iii) early Holocene (~11.7 ka B.P.)—caused massive remobilization and carbon degradation from permafrost across northeast Siberia. This amplified permafrost carbon release by one order of magnitude, particularly during the last deglaciation when global sea-level rise caused rapid flooding of the land area thereafter constituting the vast East Siberian Arctic Shelf. Demonstration of past warming-induced release of permafrost carbon provides a benchmark for the sensitivity of these large carbon pools to changing climate.

See also:

Title: "New Climate Warnings in Old Permafrost: 'It’s a Little Scary Because it’s Happening Under Our Feet.'"

https://insideclimatenews.org/news/16102020/permafrost-study-arctic-ocean-climate-change

Extract: "The study, published today in Science Advances, shows that only a few degrees of warming in the Arctic is enough "to abruptly activate large-scale permafrost thawing," suggesting a "sensitive trigger" for greenhouse gas emissions from thawing permafrost. The results also support climate models that have shown "large injections of CO2 into the atmosphere" when glaciers, and the frozen lands beneath them, melted.

"If we consider the magnitude and the speed of anthropogenic climate warming, by 1 degree Celsius (1.8 Fahrenheit) globally and 2 degrees Celsius (3.6 Fahrenheit) in the Arctic, during the past 150 years, and compare this with the first abrupt temperature increase of about 1 degree Celsius at the Bölling-Alleröd, it appears likely that large-scale permafrost thawing and carbon release is going to happen again," he said. "Our study indeed suggests that abrupt permafrost thawing represents a tipping point in the climate system.""

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

morganism

  • Frazil ice
  • Posts: 255
    • View Profile
  • Liked: 53
  • Likes Given: 1
Re: Permafrost general science thread
« Reply #124 on: October 27, 2020, 02:29:51 AM »
this is partly OT but,


Microbial Diversity Below The Seafloor Is As Rich As On Earth's Surface



"D'Hondt analyzed 299 samples of marine sediment collected as core samples from 40 sites around the globe. Their sample depths ranged from the seafloor to 678 meters below it. To accurately determine the diversity of microbial communities, the authors extracted and sequenced DNA from each frozen sample under the same clean laboratory condition.

The 16S rRNA gene sequences (approximately 50 million sequences) obtained through comprehensive next-generation sequencing were analyzed to determine microbial community composition in each sample. From these 50 million sequences, the research team discovered nearly 40,000 different types of microorganisms in marine sediment, with diversity generally decreasing with depth. The team found that microbial community composition differs significantly between organic-rich sediment of continental margins and nutrient-poor sediment of the open ocean, and that the presence or absence of oxygen and the concentration of organic matter are major factors in determining community composition.

By comparing their results to previous studies of topsoil and seawater, the researchers discovered that each of these three global biomes--marine sediment, topsoil, and seawater--has different microbial communities but similar total diversity. "It was an unexpected discovery that microbial diversity in the dark, energy-limited world beneath the seafloor is as diverse as in Earth's surface biomes," said Hoshino.

Furthermore, by combining the estimates of bacterial and archaeal diversity for these three biomes, the researchers found that bacteria are far more diverse than archaea--microbes distinct from bacteria and known for living in extreme environments--on Earth."

http://astrobiology.com/2020/10/microbial-diversity-below-the-seafloor-is-as-rich-as-on-earths-surface.html


kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #125 on: October 27, 2020, 01:43:34 PM »
Maybe even completely since the articl/paper does not mention permafrost at all.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

gerontocrat

  • First-year ice
  • Posts: 9587
    • View Profile
  • Liked: 3803
  • Likes Given: 29
Re: Permafrost general science thread
« Reply #126 on: October 27, 2020, 04:57:15 PM »
But we have to wait for a peer-reviewd paper next year to find out how whoops! it really is.

https://www.theguardian.com/science/2020/oct/27/sleeping-giant-arctic-methane-deposits-starting-to-release-scientists-find
'Sleeping giant' Arctic methane deposits starting to release, scientists find
Exclusive: expedition discovers new source of greenhouse gas off East Siberian coast has been triggered

Quote
Scientists have found evidence that frozen methane deposits in the Arctic Ocean – known as the “sleeping giants of the carbon cycle” – have started to be released over a large area of the continental slope off the East Siberian coast, the Guardian can reveal.

High levels of the potent greenhouse gas have been detected down to a depth of 350 metres in the Laptev Sea near Russia, prompting concern among researchers that a new climate feedback loop may have been triggered that could accelerate the pace of global heating.

The slope sediments in the Arctic contain a huge quantity of frozen methane and other gases – known as hydrates. Methane has a warming effect 80 times stronger than carbon dioxide over 20 years. The United States Geological Survey has previously listed Arctic hydrate destabilisation as one of four most serious scenarios for abrupt climate change.

The international team onboard the Russian research ship R/V Akademik Keldysh said most of the bubbles currently are dissolving in the water but methane levels at the surface are four to eight times what would normally be expected and this is venting into the atmosphere.

At this moment, there is unlikely to be any major impact on global warming, but the point is that this process has now been triggered. This East Siberian slope methane hydrate system has been perturbed and the process will be ongoing,” said the Swedish scientist Örjan Gustafsson of Stockholm University in a satellite call from the vessel.

The scientists – who are part of a multi-year International Shelf Study Expedition – stressed their findings are preliminary. The scale of methane releases will not be confirmed until they return, analyse the data and have their studies published in a peer-reviewed journal.

But the discovery of potentially destabilised slope frozen methane raises concerns that a new tipping point has been reached that could increase the speed of global heating. The Arctic is considered ground zero in the debate about the vulnerability of frozen methane deposits in the ocean. With the Arctic temperature now rising more than twice as fast as the global average, the question of when – or even whether – they will be released into the atmosphere has been a matter of considerable uncertainty in climate computer models.

The 60-member team on the Akademik Keldysh believe they are the first to observationally confirm the methane release is already under way across a wide area of the slope about 600km offshore.


The latest discovery potentially marks the third source of methane emissions from the region. Semiletov, who has been studying this area for two decades, has previously reported the gas is being released from the shelf of the Arctic – the biggest of any sea.

For the second year in a row, his team have found crater-like pockmarks in the shallower parts of the Laptev Sea and East Siberian Sea that are discharging bubble jets of methane, which is reaching the sea surface at levels tens to hundreds of times higher than normal. This is similar to the craters and sinkholes reported from inland Siberian tundra earlier this autumn.
"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)

morganism

  • Frazil ice
  • Posts: 255
    • View Profile
  • Liked: 53
  • Likes Given: 1
Re: Permafrost general science thread
« Reply #127 on: October 27, 2020, 11:03:40 PM »
Scary.

Scarier how the russians and asians talk about the hydrate release, and the USA and brits say it will never happen, or will not be catastrophic if it does.

The post about the bacteria above was posted here because it is the only active soil bacteria thread going now.

It appears when the methanotrophs digest the methane, they split out the hydrogen, and release the C.

There is only one researcher working in Antartica, on ice core studies, that is looking at the C in the cores, and he says he thinks the 13/14 shows that the high CO2/CO has signatures that it has been processed by methanotrophs. He also says that in every sample that had bubbles he looked at, that there were dormant methanotrophs.  He believes it is possible that all these gas bubble samples were originally saturated with methane, and that the trophs have slowly been converting over the millennia.
He speculates that the very high geo record of CO2 peaks is actually times that the "hydrate gun" went off, by pointing out that the methanotrophs must have been lofted into the atmosphere to be found in all the ice cores he has looked at.

(citation lost on old hard drive, circa 2003-5 i think)

With the papers postulation of separate populations in the field, if you looked for fossilized bacteria populations in the ice cores, you might be able to ID if they were seabed, soil, or seawater water source. There have been recent studies on the aero populations of microbes of diff families also, they would also likely have a distinct group of families.

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #128 on: October 28, 2020, 08:35:28 PM »
The Permafrost general science thread is mainly for just that. The methane release has it´s own thread:

https://forum.arctic-sea-ice.net/index.php/topic,12.0.html
Welcome to the Arctic Sea Ice Forum - Arctic Methane Topic!

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

nanning

  • Nilas ice
  • Posts: 2401
  • 0Kg CO₂, 37 KWh/wk,125L H₂O/wk, No offspring
    • View Profile
  • Liked: 304
  • Likes Given: 20397
Re: Permafrost general science thread
« Reply #129 on: November 03, 2020, 04:57:01 AM »
The Observer / Archaeology
Secrets of the ice: unlocking a melting time capsule

https://www.theguardian.com/science/2020/nov/01/secrets-of-the-ice-unlocking-a-melting-time-capsule-archaeology-glaciers


This is Important imo.


Quote
In a year when the unthinkable has become the everyday, when profound changes to lifestyle, economy, travel, ambition and health have been forced upon billions of us by a tiny virus, at a time when science has trumped even the most bombastic rhetoric, it is surely important to stop and reflect on the environmental consequences of our prior economic model. We may soon look back on the Covid-19 pandemic as the good old days before climate change raced away from us.

Will we soon be swapping our smartphones for atlatl, those ingenious ancient spear-throwing devices? It’s too soon to say, but archaeologists have the luxury of a very long view.

“Technological advancement is not permanent. It can fluctuate back and forth,” says Jarman. “We’ve seen that happen throughout human history, and it would be hubris to think that it couldn’t happen again,” he says. “I hope that if it does, that is because we have intentionally managed a soft landing, choosing sustainable technology because we want to, and we know it’s the right thing to do, rather than being forced into it.”

"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
"It is preoccupation with what other people from your groups think of you, that prevents you from living freely and nobly" - Nanning
Why do you keep accumulating stuff?

Ken Feldman

  • Nilas ice
  • Posts: 1443
    • View Profile
  • Liked: 238
  • Likes Given: 144
Re: Permafrost general science thread
« Reply #130 on: November 10, 2020, 12:51:13 AM »
A just-published study on methane emissions from Siberian lakes shows that the water column of deeper lakes acts as a microbial filter that prevents methane emissions into the atmosphere.

https://bg.copernicus.org/preprints/bg-2020-317/

Quote
Savvichev, A., Rusanov, I., Dvornikov, Y., Kadnikov, V., Kallistova, A., Veslopolova, E., Chetverova, A., Leibman, M., Sigalevich, P., Pimenov, N., Ravin, N., and Khomutov, A.: The water column of the Yamal tundra lakes as a microbial filter preventing methane emission, Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-317, in review, 2020.

Abstract. Microbiological, molecular ecological, biogeochemical, and isotope geochemical research was carried out in four lakes of the central part of the Yamal Peninsula in the area of continuous permafrost. Two of them were large (73.6 and 118.6 ha) and deep (up to 10.6 and 12.3 m) mature lakes embedded into all geomorphological levels of the peninsula, and two others were smaller (3.2 and 4.2 ha) shallow (up to 2.3 and 1.8 m) lakes which appeared as a result of thermokarst on constitutional (segregated) ground ice. We collected samples in August 2019. The Yamal tundra lakes exhibited high phytoplankton production (340–1200 mg C m−2 day−1) during the short summer season. Allochthonous and autochthonous, both particulate and dissolved organic matter was deposited to the bottom sediments, where methane production occurred due to anaerobic degradation (90–1000 µmol СН4 dm−3). The rates of hydrogenotrophic methanogenesis appeared to be higher in the sediments of deep lakes than in those of the shallow ones. In the sediments of all lakes, Methanoregula and Methanosaeta were predominant components of the archaeal methanogenic community. Methane oxidation (1.4–9.9 µmol dm−3 day−1) occurred in the upper sediment layers simultaneously with methanogenesis. Methylobacter tundripaludum (family Methylococcaceae) predominated in the methanotrophic community of the sediments and the water column. The activity of methanotrophic bacteria in deep mature lakes resulted in a decrease of the dissolved methane concentration in lake water from 0.8–4.1 µmol CH4 L−1 to 0.4 µmol CH4 L−1, while in shallow thermokarst lakes the geochemical effect of methanotrophs was much less pronounced. Thus, only small shallow Yamal lakes may contribute significantly to the overall diffusive methane emissions from the water surface during the warm summer season. The water column of large deep lakes on Yamal acts, however, as a microbial filter preventing methane emission into the atmosphere.

 

oren

  • Moderator
  • First-year ice
  • Posts: 6412
    • View Profile
  • Liked: 2385
  • Likes Given: 2029
Re: Permafrost general science thread
« Reply #131 on: November 20, 2020, 10:08:27 AM »
I wonder what the proportion of lakes in Yamal is between "shallow thermokarst lakes" and "deep mature lakes".

gerontocrat

  • First-year ice
  • Posts: 9587
    • View Profile
  • Liked: 3803
  • Likes Given: 29
Re: Permafrost general science thread
« Reply #132 on: November 20, 2020, 12:10:05 PM »
I wonder what the proportion of lakes in Yamal is between "shallow thermokarst lakes" and "deep mature lakes".
Can one find a nice little table to tell us the answer? NO.

But as far as Western Siberia is concedrned, the topography suggests shallow (see image) and that new small lakes are appearing while large mature lakes are draining.

http://www.izdatgeo.ru/pdf/earth_cryo/2015-2/100_eng.pdf
Quote

Comparative analysis of the above data on the number of the disappeared and newly formed lakes and their total areas in the entire permafrost zone of Western Siberia indicates another important pattern: with the total areas of the disappeared (14,826 hectares) and newly formed lakes (13,649 hectares) lakes, the number of the newly formed lakes is approximately 18 times greater than the number of the disappeared lakes.

Hence, new thermokarst lakes are much smaller in size than the preceding ones. One can suppose then that the observed acceleration of the thermokarst processes caused by climate warming will be accompanied by significant growth in the number of small thermokarst lakes in the permafrost zone of Western Siberia

Acceleration of the thermokarst processes caused by climate warming and noted by many researchers results in more intense formation of new lakes, which is, according to the results obtained, the most characteristic process for the continuous permafrost subzone of Western Siberia. As follows from the above, the newly formed thermokarst lakes are usually small in
size. According to the experimental data by [Audry et al., 2011; Pokrovsky et al., 2011], small thermokarst lakes (in) Western Siberia are plentiful natural sources of methane. Therefore, one can assume increase in the methane emission into the air, as the number of small thermokarst lakes increases in the permafrost zone, which will contribute to intensification of the greenhouse effect.

https://tc.copernicus.org/articles/8/1177/2014/tc-8-1177-2014.pdf
Quote
The acceleration of the permafrost thaw in the northern portion of western Siberia (Kirpotin et al., 2009a, b; Bryksina et al., 2009; Dneprovskaya et al., 2009; Bryksina and Kirpotin, 2012) should increase the amount of small soil subsidence and permafrost depressions while decreasing the amount of large (mature) lakes. For example, a net increase in
the amount of lakes was observed for the Nadym watershed (north of western Siberia and close to continental sites of this #study), which is explained by the formation of small lakes, while the larger lakes fragment after partial drainage (Karlsson et al., 2014).
« Last Edit: November 20, 2020, 12:17:43 PM by gerontocrat »
"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)

kassy

  • Young ice
  • Posts: 2582
    • View Profile
  • Liked: 1204
  • Likes Given: 1060
Re: Permafrost general science thread
« Reply #133 on: November 20, 2020, 05:05:16 PM »
The large lakes are an established ecosystem so it makes sense that the bacteria over time evolve to take advantage of the extra methane higher in the watercolumn (the research does not strike me as new but it could be for these specific lakes).

All new lakes are shallow thermokarst lakes so it does not mean that much.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.