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Messages - prokaryotes

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1
Consequences / Re: Past Extinction Events, as an Analog for Today
« on: July 16, 2019, 09:32:00 PM »
Made a video.

2
Consequences / Re: The Climatic Effects of a Blue Ocean Event
« on: July 15, 2019, 11:55:04 PM »
Do not focus so much on the ice extent as a switch to something new, Arctic sea ice decline is more like the most visible positive feedback from a warmer climate. Things already change drastically and less sea ice will make those changes more pronounced.

Think of the satellite observed sea ice loss since 1979 as a transition modulated by the amount of greenhouse gases. General understanding currently is that the jet stream (the polar vortex) becomes more meandered, resulting in more stuck weather patterns - due to slower moving Rossby waves, since the polar vortex jets expand farther south.

Interactions also to consider, rate of iceberg and freshwater discharge from Greenland and river runoff in the Arctic circle, Ocean currents, waves and coastal erosion, salinity/halocline in the Arctic Ocean, NAO (see for instance this https://twitter.com/climate_ice/status/1150478225241305088).

General trend is temperature gradient in the northern hemisphere weakens, with the exception in the Greenland regions (see for instance Cold Blob anomaly), OR where cold Arctic air dives farther south, meets much warmer air, storminess increases (Hansen: Frontal (cyclonic) storms with hurricane-like winds, which, with rising seas and storm surges, will devastate thousands of coastal cities)  The planet is on a path to a warmer state, losing polar ice.

Implications are far reaching, negative for crop cultivation, biodiversity, ecosystems, atmospheric chemistry, profound on every level, and likely will last roughly 200,000 to 1,000,000 years - based on past such events in geological times.

However, our civilization can modulate the extent of change still, and maybe we develop more sophisticated negative carbon technologies - but at this time things like carbon capture and storage are not economically viable, remain largely untested, containments may leak over time.

3
Consequences / Past Extinction Events, as an Analog for Today
« on: July 15, 2019, 09:03:38 PM »
Quote
Study the parallels between hyperthermals and current climate change is by finding a suitable analogue – that is, the hyperthermal that was most similar to the kind of global warming that we’re seeing today.

Carbon input during the PETM was likely still 10 times as slow as in the modern era. Indicators of PETM ocean acidification demonstrate strong dissolution, but modern rates are faster.

The build up period that led to the PETM, in which around 3tn tonnes of CO2 was released into to the atmosphere, may have taken thousands of years. In comparison, the onset of current climate change has taken less than two centuries.

Research suggests that the rate of carbon release as a result of human-driven climate change, and its resultant effect on the world’s oceans, could be “completely unprecedented”.[3]

Quote
The Paleocene–Eocene Thermal Maximum has become a focal point of considerable geoscience research because it probably provides the best past analog by which to understand impacts of global climate warming and of massive carbon input to the ocean and atmosphere, including ocean acidification.
https://en.wikipedia.org/wiki/Paleocene–Eocene_Thermal_Maximum

Killing models during the Permian–Triassic mass extinction
[2]

STRESSORS
Temperature
Ocean acidification (Reduced PH)
Deoxygenation (extreme condition in Ocean, leading to hydrogen sulfide production)
Mercury loading
Increased dissolved seawater CO2

Multiple stressors can have synergistic impacts For example, high temperatures increase an organism’s oxygen demand and reduce its aerobic scope, while lower pH may reduce the oxygen-carrying capacity of blood pigments and seasonal hypoxia can reduce oxygen availability.

Likewise, temperature can have variable effects on susceptibility to metal pollution, and metal pollution can in turn reduce thermal tolerance.[1]

EVENTS

Flood Basalts and Mass Extinctions - Assessing volatile release, environmental change, and biological extinction at finer temporal resolution should be a top priority to refine ancient hyperthermals as analogs for anthropogenic climate change
   
Quote
  • Flood basalts, the largest volcanic events in Earth history, triggered dramatic environmental changes on land and in the oceans.

    Rapid volcanic carbon emissions led to ocean warming, acidification, and deoxygenation that often caused widespread animal extinctions.

    Animal physiology played a key role in survival during flood basalt extinctions, with reef builders such as corals being especially vulnerable.

    The rate and duration of volcanic carbon emission controlled the type of environmental disruption and the severity of biological extinction.
[1]


[1]

THRESHOLDS / AMPLIFYING FEEDBACKS
A new model from MIT indicates that previous consensus climate models have underestimated the atmospheric CO2 levels required to push the ocean beyond a tipping point that would lead to mass extinction in the coming millenia:

Title: "Breaching a “carbon threshold” could lead to mass extinction"

http://news.mit.edu/2019/carbon-threshold-mass-extinction-0708

Quote
We find that the observed pink noise behavior is intrinsic to Earth’s climate dynamics, which suggests a range of possible implications, perhaps the most important of which are ‘resonances’ in which processes couple and amplify warming https://news.yale.edu/2018/09/04/think-pink-better-view-climate-change

QUESTIONS

1. What role played hydrogen sulfide in past extinction events?

2. What can we exactly conclude about the rate of emissions today vs past events? What does it mean for ecosystem resilience, and planetary boundaries?

3. How will Earth's geomorphology respond to uptake in weathering, deglaciation - mass balance changes at the poles?

4. Why were some events characterized by extensive anoxia and widespread black shale deposition whereas other events were dominated by warming and acidification?[1]

5. What were the most important environmental kill mechanisms responsible for eliminating marine and terrestrial organisms?[1]


ANSWERS

1. The hydrogen sulfide at the Permian (and other extinctions) likely reflects an extreme development of the coastal "dead zones" that we see today. In terms of the cause, the consensus appears to have shifted somewhat towards nutrient runoff (and eutrophication) as the primary driver, rather than slowing ocean circulation as might have been proposed 10-15 years ago.

2. The rate of emission, and therefore the rate of environmental disruption, likely provides a first-order constraint for extinctions/adaptation - modulated by duration.

5. Species extinction and survival were likely rooted in their physiological responses to temperature, pH, oxygen, and related stressors, and a growing understanding from extant organisms provides clues to understand biotic vulnerability during hyperthermals.

[1]

TERMINOLOGY
Oceanic Anoxic Event (OAE) and mass extinctions are considered to be hyperthermals - usually associated with flood basalt eruptions.[1]. Phases of rapid global warming, known collectively as hyperthermals.[3]

Flood basalts are a subset of large igneous provinces (LIPs), the terms flood basalt and LIP are often used interchangeably, although the former should be reserved for the extrusive component of an LIP. Flood basalts are giant volcanic eruptions or series of eruptions that cover large stretches of land or the ocean floor with basalt lava.

RELATED

Hydrogen sulfide and environmental stresses / H2S is produced in response to numerous plant stresses, including heavy metal exposure, temperature, drought and salt stress. https://www.sciencedirect.com/science/article/abs/pii/S0098847218311146

Ammonium intoxication is a previously unexplored killing mechanism for extinctions. https://www.sciencedirect.com/science/article/pii/S0012821X19302407



REFERENCES

1. Flood Basalts and Mass Extinctions, Matthew E. Clapham and Paul R. Renne 2019 https://www.annualreviews.org/doi/pdf/10.1146/annurev-earth-053018-060136

2. Hyperthermal-driven mass extinctions: killing models during the Permian–Triassic mass extinction, Michael J. Benton 2018 https://royalsocietypublishing.org/doi/full/10.1098/rsta.2017.0076

3. Hyperthermals: What can they tell us about modern global warming? https://www.carbonbrief.org/hyperthermals-what-can-they-tell-us-about-modern-global-warming

4
Title: "Breaching a “carbon threshold” could lead to mass extinction"
Made a new topic https://forum.arctic-sea-ice.net/index.php/topic,2802.0.html

5
Consequences / Re: Hurricane Season 2019
« on: July 13, 2019, 07:42:55 PM »
Quote
Barry's center is meandering along the Louisiana coast near 29.7N/92W.
https://twitter.com/pppapin/status/1150088671791476736

6
Consequences / Re: Hurricane Season 2019
« on: July 13, 2019, 05:59:38 PM »
According the the NOAA/NHC site, the path of maximum rainfall seems to be using the Mississippi river as a roadmap all the way up to Tennessee.

And Barry formed originally there, mentioned here https://youtu.be/RuNGJsFtv-U?t=216

7
Consequences / Re: Hurricane Season 2019
« on: July 13, 2019, 05:12:12 PM »
Barry was just upgraded to Hurricane status. https://twitter.com/NOAASatellites/status/1150059448829972480

Is there potential for stalling, and at what point is a storm considered to stall?

Quote
NAM 3KM has Barry staying off land for at least the next 24 hours. This model was pretty accurate in terms of track for this system
https://www.wunderground.com/cat6/Barry-Churns-Near-Louisiana-Coast-Massive-Rains-Still-Expected#comment-4538153747

8
Permafrost / Re: Arctic Methane Release
« on: July 13, 2019, 04:27:50 AM »
Made a new video. Soil layers of permafrost that scientists expected to remain frozen for at least 70 more years have already begun thawing.

The Current State of Arctic PERMAFROST THAW


9
The rest / Re: Good music
« on: July 09, 2019, 09:41:31 AM »

10
Permafrost / Re: Arctic Methane Release
« on: July 09, 2019, 02:35:52 AM »
New study, Direct observation of permafrost degradation and rapid soil carbon loss in tundra
https://www.nature.com/articles/s41561-019-0387-6

Quote
Evidence suggests that 5–15% of the vast pool of soil carbon stored in northern permafrost ecosystems could be emitted as greenhouse gases by 2100 under the current path of global warming.

However, direct measurements of changes in soil carbon remain scarce, largely because ground subsidence that occurs as the permafrost soils begin to thaw confounds the traditional quantification of carbon pools based on fixed depths or soil horizons.

This issue is overcome when carbon is quantified in relation to a fixed ash content, which uses the relatively stable mineral component of soil as a metric for pool comparisons through time. We applied this approach to directly measure soil carbon pool changes over five years in experimentally warmed and ambient tundra ecosystems at a site in Alaska where permafrost is degrading due to climate change.

We show a loss of soil carbon of 5.4% per year (95% confidence interval: 1.0, 9.5) across the site. Our results point to lateral hydrological export as a potential pathway for these surprisingly large losses. This research highlights the potential to make repeat soil carbon pool measurements at sentinel sites across the permafrost region, as this feedback to climate change may be occurring faster than previously thought.

Summary
Quote
“This study was novel because we used new methods to directly track the soil carbon losses, and they were much higher than we previously thought,” Schuur said. “This suggests that not only is carbon being lost through greenhouse gases directly to the atmosphere but also dissolved in waters that flow through the soil and likely carried carbon into streams, leaves and rivers.”
https://news.nau.edu/schuur-carbon-permafrost-study



Thawing permafrost affects plant and soils in tundra ecosystems, and ultimately the storage of carbon in permafrost soils. The surface of tundra subsides as ice in permafrost melts and drains. This can mask the loss of soil carbon through time that occurs as a result of soil microbial activity converting soil organic matter into greenhouse gases carbon dioxide and methane. Accounting for ground subsidence as a result of thaw revealed that substantial quantities of soil carbon were loss both directly to the atmosphere as carbon dioxide, but also dissolve in water that drained from this site. Soil carbon loss from permafrost ecosystems that ends up in the atmosphere at greenhouse gases can ultimately accelerate climate change

11
Arctic sea ice / Re: 2019 vs 2012
« on: July 09, 2019, 01:19:50 AM »
Atmospheric CO2 levels are currently ~ 15 ppm higher than 2012.

This is most relevant toward the latter portion of melting season when heat escape becomes a bigger factor.
What about the winds up there, is it very stormy?

12
Antarctica / Re: Sea Ice Extent around Antarctica
« on: July 09, 2019, 12:27:33 AM »


Made this video on recent Parkinson et al. PNAS paper, feedback is welcome. Though the more extended version posted here https://climatestate.uscreen.io/programs/the-mystery-of-the-antarctic-sea-ice-puzzle goes into more details with the ozone hole, and includes a brief segment from this 2018 talk https://climatestate.uscreen.io/programs/the-circulation-of-the-antarctic-margins-in-a-changing-climate by NASA's Andy Thompson, who elaborates on grounding line - slope vortexes, eddies, models, and SAM.

The main take-away from Parkinson et al, for me is, that the Amundsen current feeds into the WAIS region, while sea-ice there also most extensively in decline.

13
Get an idea about upcoming production quality, just published this feature film

Watch full version 40 mins length https://climatestate.uscreen.io/programs/feature-film-on-climate-action-climate-state-tipping-point

14
YouTube forces us to remove hundreds of videos from our channel, just because they were posted before, or only slightly edited, deeming them as having no educational value. Subsequently, setup a new Netflix-style streaming platform this week, https://climatestate.uscreen.io

There are over 300 videos so far, many classics, many videos no longer available on YouTube, or only available on small channels with little views.

Summary


About 30 percent of videos are freely available, however to cover the monthly costs of $149 some videos require a subscription. If you find a video missing or want something added please contact me http://climatestate.com/publishing-climate-videos-with-climate-state As I add more content, people signing-up, and tweak settings, more videos will become public.

Everybody can watch any video when using the 7-Day trial of the Monthly Plan. Your suggestions and feedback is welcome, thank you.

15
The rest / Re: Good music
« on: June 22, 2019, 06:46:50 AM »
Very chill positive study summer vibes live stream

16
Arctic sea ice / Re: SMOS
« on: June 21, 2019, 11:03:38 PM »
Just curious, but can this pickup on flaw polynyas?

Quote
Areas of flaw polynyas in the ESAS increased dramatically (by up to five times) during the last decades, and now exceed the total area of Siberian wetlands.
Link

17
Consequences / Re: Drought 2019
« on: June 21, 2019, 12:51:01 AM »
More than 500 arrested after protests and clashes as India water crisis worsens https://edition.cnn.com/2019/06/20/india/chennai-water-crisis-intl-hnk/index.html

18
Consequences / Re: Drought 2019
« on: June 20, 2019, 10:14:45 PM »
Re NW: While this is an interesting topic can we have this in a dedicated thread. Would be more interested in learning how India is addressing the drought, what the results are and so on.

19
Consequences / Re: Drought 2019
« on: June 20, 2019, 09:50:39 PM »
India's ongoing drought affecting many states of this huge country

Quote
The drought, which officials say is worse than the 1972 famine [..] The village of Hatkarwadi, about 20 miles from Beed in Maharashtra state, is almost completely deserted.
[..] Groundwater, the source of 40% of India’s water needs, is depleting at an unsustainable rate, Niti Aayog, a governmental thinktank, said in a 2018 report. Twenty-one Indian cities – including Delhi, Bengaluru, Chennai and Hyderabad – are expected to run out of groundwater by 2020, and 40% of India’s population will have no access to drinking water by 2030, the report said.
https://www.theguardian.com/world/2019/jun/12/indian-villages-lie-empty-as-drought-forces-thousands-to-flee

From a 2017 news article..
Quote
Chennai's Drinking Water Cut By Half Amid Worst Drought In 140 Years
https://www.ndtv.com/chennai-news/chennai-turns-dry-as-worst-drought-in-140-years-hits-tamil-nadu-1717014

20
Consequences / Re: Heatwaves
« on: June 20, 2019, 09:39:11 PM »
Srini Swaminathan took the video of Lake Puzhal as he left Chennai on a flight.
"I intentionally paid for and chose a window seat to see the drought situation of my city from above," he told CNN.

Some more context, though
Quote
The drought, which officials say is worse than the 1972 famine [..] The village of Hatkarwadi, about 20 miles from Beed in Maharashtra state, is almost completely deserted.
[..] Groundwater, the source of 40% of India’s water needs, is depleting at an unsustainable rate, Niti Aayog, a governmental thinktank, said in a 2018 report. Twenty-one Indian cities – including Delhi, Bengaluru, Chennai and Hyderabad – are expected to run out of groundwater by 2020, and 40% of India’s population will have no access to drinking water by 2030, the report said.
https://www.theguardian.com/world/2019/jun/12/indian-villages-lie-empty-as-drought-forces-thousands-to-flee

From a 2017 news article..
Quote
Chennai's Drinking Water Cut By Half Amid Worst Drought In 140 Years
https://www.ndtv.com/chennai-news/chennai-turns-dry-as-worst-drought-in-140-years-hits-tamil-nadu-1717014

21
An interesting article on the OMG project from the Nasa Earth Observatory.

Turns out the glacier is getting thicker...
My guess...

This anomaly, the Cold blob (North Atlantic) https://en.wikipedia.org/wiki/Cold_blob_(North_Atlantic) … It appears possibly related to global warming-induced melting of the Greenland ice sheet. Which suggest that at least it has a slight negative feedback on marine terminating glaciers. https://twitter.com/climatestate/status/1141083224074084353

22
Permafrost / Re: Arctic Methane Release
« on: June 20, 2019, 03:13:09 PM »
The existence of vast quantities of CH4 under the ESAS and other areas currently covered by permafrost is well known.  The question is how much CH4 will be released and how quickly it will be released as the permafrost thaws.  And it appears that S&S vastly overestimate both the amount and timing of the release, as they assume that methane plumes they observed in 2014 will continue releasing methane at the same rate.  Other observers have noted that the amount and rate of methane released drops quickly.

https://www.mdpi.com/2076-3263/9/2/67

I think what bothers Shakova is that there's up to 22km thick overburden of sediment beneath the ESS with a thinning capping of permafrost, the overburden may all be permeated with methane hydrate deposits. We may have tapped only those deposits which are closest to the surface so far. Yamal is equally problematic with 65mt deep 'pingo' type features appearing on a wholly permafrost peninsular which does not reach 50mt above sea level anywhere.

Perhaps, the smoking gun is increases in salinity?

New Mechanism for Methane Hydrate Dissociation Discovered http://climatestate.com/2019/06/19/new-mechanism-for-methane-hydrate-dissociation/

Includes Shakova 2017 & 2019 finds.

23
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: June 20, 2019, 03:01:55 PM »
Possibility of another injection of warm salty water north of Greenland with the upcoming weather.
Mercator(model) salinity 34m jan1-jun16
Are people aware that higher salt content affect the stability zone of subsea permafrost deposits?

Made a post yesterday New Mechanism for Methane Hydrate Dissociation Discovered http://climatestate.com/2019/06/19/new-mechanism-for-methane-hydrate-dissociation/

Evaporation in the Arctic, historically been low due to the lower temperatures there, but with amplifications up there, likely a profound uptake in rains too from permafrost thaw, there is the question how the Arctic Water Cycle (AWC) will contribute to saltiness as well.

Are there ESAS region specific salt buoys? 

Update, googled a bit more..

Seven Years of SMOS Sea Surface Salinity at High Latitudes: Variability in Arctic and Sub-Arctic Regions https://www.mdpi.com/2072-4292/10/11/1772/htm

The Potential and Challenges of Using Soil Moisture Active Passive (SMAP) Sea Surface Salinity to Monitor Arctic Ocean Freshwater Changes https://www.mdpi.com/2072-4292/10/6/869/htm

Stability of the arctic halocline: a new indicator of arctic climate change https://iopscience.iop.org/article/10.1088/1748-9326/aaec1e/meta

Quote
A reduction in upward oceanic heat flux. This reduction in heat flux is due to increased precipitation that leads to fresher ocean surface waters and, hence, to more stable stratification of the upper Arctic Ocean. This stratification results in cooling of the ocean surface and warming of deeper ocean layers.
https://www.jstor.org/stable/26542658?seq=1#page_scan_tab_contents

24
"While glaciovolcanism (defined as “the interactions of magma with ice in all its forms, including snow, firn and any meltwater”), may still be in its infancy; nevertheless, I provide the following links to relevant information (& two images about geomagnetism), and I note that there is more information in the 'Antarctic Tectonics' thread in the Antarctic folder; for those who are interested in learning more about this topic:

J.L. Smellie (2018), "Chapter 10 – Glaciovolcanism: A 21st Century Proxy for Palaeo-Ice",
Past Glacial Environments (Second Edition), Pages 335–375, https://doi.org/10.1016/B978-0-08-100524-8.00010-5

https://www.sciencedirect.com/science/article/pii/B9780081005248000105

Abstract: "Glaciovolcanism is a young science that has undergone a major transformation during the last 15 years. It is important for a variety of reasons but it is set to play a major role in deriving critical parameters of past ice sheets and thus greatly improve the accuracy of their reconstruction. Glaciovolcanic studies can deduce a wider range of parameters than any other methodology currently existing, including: establishing the presence of ice, its age, ice thickness, ice surface elevation, and basal thermal regime. These attributes can be acquired routinely for many glaciovolcanic sequences and, uniquely, several are quantifiable. Most glaciovolcanic terrains provide punctuated rather than continuous records of the coeval ice sheet, i.e., with numerous time gaps. Despite the gaps, glaciovolcanic studies of ice sheets have been completed successfully in the three major glaciovolcanic regions of the Earth: mainly Antarctica, but also Iceland and British Columbia (Canada). Future studies in these and other glaciovolcanic regions will considerably improve our knowledge of Earth’s water inventory and contribute to a better understanding of past ice dynamics and the impact of the cryosphere on global climate."

&

Title: "Antarctic Glaciovolcanism:

https://www2.le.ac.uk/departments/geology/people/smellie-jl/personal/ant-glaciovolc
A dedicated topic would be great, but where would it fit in?

Glaciovolcanism https://en.wikipedia.org/wiki/Glaciovolcanism

See attached image for potential glaciovolcanism hot spots, via 2018 REVIEW by Cooper etal. http://eprints.whiterose.ac.uk/124024/ . However, active faults possibly with submarine landslides could become apparent too, hence not only about volcanoes.

See my recent blog here with related studies Study: Enhanced Seismic Activity Observed in Alaska Due To Climate Change http://climatestate.com/2019/06/06/enhanced-seismic-activity-observed-due-to-climate-change/

Attempt to capture this topic in video format, for sources see http://climatestate.com/2019/06/08/video-enhanced-seismic-activity-observed-in-alaska-due-to-climate-change/


Maybe this terminology should be dubbed

Glacioseismicity.


25
Greenland and Arctic Circle / Re: The Bølling-Allerød warming
« on: June 07, 2019, 01:06:59 AM »
From above
Quote
Two plausible mechanisms could have linked the interval of isostatic adjustment with enhanced volcanism: 1) increased melt production generated through decompression in the shallow mantle (Maclennan et al., 2002), or 2) reduced storage time of crustal magmas through regional adjustment in crustal stress and enhanced dike formation (Rawson et al., 2016). The near-zero timelag between regional isostatic adjustment and an abrupt increase in volcanic eruptive frequency in Southeast Alaska suggests the latter scenario is more plausible, or at least the dominant mechanism.

Supporting this supposition is the rapid mobilization of differentiated magma through multiple vents. Decompression melting would not likely have produced differentiated magmas on the time-frames observed, while previous work by others has shown that the Mount Edgecumbe magma chamber likely contained cupolas above the main basaltic chamber that already contained the more siliceous material (e.g. Myers and Sinha, 1985; Riehle et al., 1992b).

The rapid response of the Southeast Alaska system contrasts with inferred lags of volcanism several thousand years behind sealevel rise in global compilations (Kutteroff et al., 2013; Watt et al., 2013). It is plausible to think that some volcanic systems may have longer lag times behind local unloading; for example, arc systems in thicker continental crust may have longer response times (Rawson et al., 2016) than relatively isolated volcanic systems with shallow magma chambers, such as in Southeast Alaska (Riehle et al., 1994). Nevertheless, our findings highlight the importance of well-constrained regional studies to understand the rates and sensitivity of interactions between surface processes and volcanic activity.

Somewhat related I guess

Study: Enhanced Seismic Activity Observed in Alaska Due To Climate Change

Money quote

Quote
Recently, the enhanced deglacial volcanic activity in Southeast Alaska sourced from Mount Edgecumbe Volcanic field has been correlated with the rapid isostatic adjustment, occurred following a retreat of regional glaciers.

26
..
Is there a topic discussing Marine Ice Sheet Instability?

28
2500 MW melts about 1/2 Gtonne ice per year (Check my math, always)
Amundsen sea glaciers are losing about  100Gtonne/yr.

So still down in the noise.

sidd

Quote
All the datasets illustrate the previously documented accelerating mass loss of Antarctica (Rignot et al., 2011a, b; Velicogna, 2009). In 2005–2010, the ice sheet experienced ice mass loss driven by an increase in mass loss in the Amundsen Sea sector of West Antarctica (Mouginot et al., 2014). The following years showed a reduced increase in mass loss, as colder ocean conditions prevailed in the Amundsen Sea embayment sector of West Antarctica in 2012–2013 which reduced the melting of the ice shelves

The large interannual variability in mass balance in 2005– 2015, characteristic of Antarctica, nearly masks out the trend in mass loss, which is more apparent in the longer time series than in short time series. The longer record highlights the pronounced decadal variability in ice sheet mass balance in Antarctica, demonstrating the need for multidecadal time series in Antarctica, which have been obtained only by IOM and altimetry. The interannual variability in mass balance is driven almost entirely by surface mass balance processes. The mass loss of Antarctica, about 200 Gt yr−1 in recent years, is only about 10 % of its annual turnover of mass (2200 Gt yr−1 ), in contrast with Greenland where the mass loss has been growing rapidly to nearly 100 % of the annual turnover of mass.

The annual turnover of mass of Antarctica is about 2200 Gt yr−1 (over 6 mm yr−1 of SLE), 5 times larger than in Greenland (Wessem et al., 2017). In contrast to Greenland, ice and snow melt have a negligible influence on Antarctica’s mass balance, which is therefore completely controlled by the balance between snowfall accumulation in the drainage basins and ice discharge along the periphery.

200 Gt from entire continent, i would think most from the WAIS. https://www.earth-syst-sci-data.net/10/1551/2018/essd-10-1551-2018.pdf

29
While the linked research, indicating more rapid bedrock uplift in Amundsen Sea Embayment, seems like good news, if one refers to projections from ice sheet models that do not include Pollard's & DeConto's ice cliff and hydrofacturing mechanism and which assume radiative forcing scenarios of RCP 4.5 or less.  However, if one assumes radiative forcing scenarios close to BAU for the next two decades and projections from Pollard & DeConto's recent work, then Barletta et al (2018)'s finding are actually bad news regarding the potential collapse of the WAIS this century.

V.R. Barletta el al. (22 Jun 2018), "Observed rapid bedrock uplift in Amundsen Sea Embayment promotes ice-sheet stability," Science,:
Vol. 360, Issue 6395, pp. 1335-1339, DOI: 10.1126/science.aao1447.

http://science.sciencemag.org/content/360/6395/1335
Because there is a volcano beneath Pine Island Glacier, and because

Evidence of an active volcanic heat source beneath the Pine Island Glacier https://www.nature.com/articles/s41467-018-04421-3 and because there was a recent eruption

A recent volcanic eruption beneath the West Antarctic ice sheet https://www.nature.com/articles/ngeo106 Ancient Antarctic eruption noted http://news.bbc.co.uk/2/hi/science/nature/7194579.stm the uplift may mean that the heat source also advances. 


Quote
The localization of mantle helium to glacial meltwater reveals that volcanic heat induces melt beneath the grounded glacier and feeds the subglacial hydrological network crossing the grounding line. The observed transport of mantle helium out of the Ice Shelf cavity indicates that volcanic heat is supplied to the grounded glacier at a rate of ~ 2500 ± 1700 MW, which is ca. half as large as the active Grimsvötn volcano on Iceland. Our finding of a substantial volcanic heat source beneath a major WAIS glacier highlights the need to understand subglacial volcanism, its hydrologic interaction with the marine margins, and its potential role in the future stability of the WAIS.

ps. can someone suggest a good open study on Marine ice cliff instability?
Here https://www.sciencedirect.com/science/article/pii/S0012821X14007961

30
Consequences / Re: The 5 Big Climate Unknowns?
« on: July 27, 2018, 06:01:27 PM »
Two unknowns possibly worth a look is the ocean acidity increasing regarding both the the death collapse of coral reefs (circa 2050) and the impact on small deep ocean species eg planktons and their connections with the entire ocean life cycles. and therefore food sources. Included in this is the somewhat interconnected timing of oxygen death zones in the seas and oceans.
Indeed, probably have to make an update with the top 10 unknowns.

31
Consequences / The 5 Big Climate Unknowns?
« on: July 27, 2018, 04:14:11 AM »
I went and made a video on what I think are The 5 Big Climate Unknowns.

Climate unknowns include the rate of sea level rise, ozone loss, how the Gulf Stream will react and what it possibly means, the Earth's response, and the potential for extra methane release from methane clathrates, stored at continental margins. There are many more climate unknowns, for example elaborated in this article https://thinkprogress.org/what-are-the-unknown-unknowns-of-global-warming-1438d934bdee



I would be interested if you think there is an equal unknown, such as Mountain Pine Beetle infestations, destroying carbon sinks. What would you have added, or think is missing?

33
Antarctica / Re: Sea Ice Extent around Antarctica
« on: November 25, 2017, 06:29:12 PM »
So the last couple of years, sea ice progressively gets worse. What could this mean for glaciers? Are we seeing the beginning of a ramp up of ice retreat in Antarctica?

34
There is another new study on winds due to CO2 increase, causing more upwelling, and may cause through this mechanism warm water intrusion at Totten glacier -- holds more than 11 feet of sea level rise, located in East Antarctica


Press release https://news.utexas.edu/2017/11/01/winds-driving-warm-water-under-east-antarctic

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This is kind of a summary, though planning to publish a video on surface melt vs basal.

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Rapid collapse of Antarctic glaciers could flood coastal cities by the end of this century. Based on an article written by Eric Holthaus.


38
Worth another subcategory: "Holocene prehistory" or "Arctic methane".
Somehow it makes me worry a little less about a Methane bomb: The comparison scale to back then is logarithmic and it looks there could have been a pretty huge release...
Is there any data (spike in proxy record? Model anomaly?) on any impact?
The events are linked to the Meltwater Pulse 1A


Quote
Meltwater pulse 1A occurred in a period of rising sea level and rapid climate change, known as Termination I, when the retreat of continental ice sheets was going on during the end of the last ice age. Several researchers have narrowed the period of the pulse to between 13,500 and 14,700 calendar years ago with its peak at about 13,800 calendar years ago.[3] The start of this meltwater event coincides with or closely follows the abrupt onset of the Bølling-Allerød (B-A) interstadial and warming in the NorthGRIP ice core in Greenland at 14,600 calendar years ago.[4] During meltwater pulse 1A, sea level is estimated to have risen at a rate of 40–60 mm (0.13–0.20 ft)/yr.
https://en.wikipedia.org/wiki/Meltwater_pulse_1A

This means that there was warming/deglaciation going on, and then about 2.5 thousand years later the craters appeared in the Barents Sea region, once the thick ice sheets there retreated enough. The region was likely rather shallow at the time, other than that is it unclear how these deposits compare to today's coastal ice-sheet topography and methane deposits configuration, around Greenland and Antarctica.

Quote
Despite their infrequency, the impact of such blow-outs may still be greater than impact from slow and gradual seepage

That's a good point, forgot to mention this.

39
Prok
Wonder if the above would be easier to find in the Methane thread?
Terry
I really don't mind, but to me it appears significant enough, its kind of different to permafrost/soil methane sources. The search gave 3 entries for methane crater, all not really in scope of a focused discussion for ocean craters. But if the moderation feels we should move this topic, go ahead, please.

Cheers

40
A new study in Science shows that hundreds of massive, kilometre –wide, craters on the ocean floor in the Arctic were formed by substantial methane expulsions https://cage.uit.no/news/massive-craters-formed-methane-blow-outs-arctic-sea-floor


The massive craters were formed around 12,000 years ago, but are still seeping methane and other gases. Illustration: Andreia Plaza Faverola

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Video transcript http://climatestate.com/2017/06/04/like-champagne-opened-methane-explosions-resulted-in-ocean-craters

Related press conference from 2016
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There are several hundred of craters in the area. Over one hundred of them are up to one kilometer wide. Illustration: K. Andreassen/CAGE

The craters are connected to deeper gas chimneys, showing gas flow from deeper hydrocarbon reservoirs. Hundreds of gas flares are seen in the water above. Illustration: M. Winsborrow

Related Links
Massive Craters Formed By Methane Blow-outs From The Arctic Sea Floor https://cage.uit.no/news/massive-craters-formed-methane-blow-outs-arctic-sea-floor

Like ‘champagne bottles being opened’: Scientists document an ancient Arctic methane explosion https://www.washingtonpost.com/news/energy-environment/wp/2017/06/01/like-champagne-bottles-being-opened-scientists-document-an-ancient-arctic-methane-explosion

Methane GWP, How Bad of a Greenhouse Gas Is Methane? https://www.scientificamerican.com/article/how-bad-of-a-greenhouse-gas-is-methane/

Massive craters formed by methane blow-outs from the Arctic sea floor https://phys.org/news/2017-06-massive-craters-methane-blow-outs-arctic.html

Methane exploded from Arctic sea-floor as Ice Age ended https://www.nature.com/news/methane-exploded-from-arctic-sea-floor-as-ice-age-ended-1.22095

View of the methane seeps in the Arctic

Massive craters on Arctic Ocean floor caused by methane blow out

Scientists just found telltale evidence of an ancient methane explosion in the Arctic
/ A methane mound in the Canadian High Arctic, Stephen Grasby https://www.washingtonpost.com/news/energy-environment/wp/2017/04/21/scientists-just-found-telltale-evidence-of-an-ancient-methane-explosion-in-the-arctic-ocean

Blow-out craters on the Arctic seafloor

Animation: From Glaciation to Global Warming – A Story of Sea Level Change (Titanic Belfast)

Methane clathrate https://en.wikipedia.org/wiki/Methane_clathrate

Images Methane bubbles collect under the ice (Natalia Shakhova) https://news.uaf.edu/ESAS2013

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Starting in the mid-1980s, the Defense Meteorological Satellite Program (DMSP) constructed eight “F-series” satellites, in bulk, with the plan to launch satellites in succession as each one failed to maintain a continuous record of Arctic sea ice extent.

But in 2016, Congress cut the program, resulting in the dismantling of the last, still not launched, satellite. It is now likely that an impending failure of the last DMSP satellites in orbit will leave the world blind until at least 2022, even as the Arctic shows signs of severe instability and decline.

While international and U.S. monitoring is still being done for ice thickness, the Trump administration has proposed cuts to satellite missions, including NOAA’s next two polar orbiting satellites, NASA’s PACE Satellite (to monitor ocean and atmospheric pollution), and the Orbiting Carbon Observatory 3 (for carbon dioxide atmospheric measurements).

All of these cuts in satellite monitoring come at a time when the world is seeing massive changes due to climate change, development and population growth. One satellite program spared Trump’s budgetary axe so far is Landsat 9, which tracks deforestation and glacial recession. How Congress will deal with Trump’s proposed cuts is unknown.

http://news.mongabay.com/2017/05/as-arctic-sea-ice-shows-record-decline-scientists-prepare-to-go-blind

42
Arctic sea ice / Re: The 2017 melting season
« on: May 27, 2017, 11:41:25 AM »
Alaska's Sea Ice Is Melting Unusually Early, 'Another Sign Arctic Is Unraveling' https://insideclimatenews.org/news/25052017/arctic-sea-ice-disappearing-alaska-climate-change-warm-winter-chukchi-sea

43
Permafrost / Re: Arctic Methane Release
« on: May 23, 2017, 11:50:10 PM »
About doi:10.5194/bg-14-2283-2017  The origin of methane in the East Siberian Arctic Shelf unraveled
with triple isotope analysis

A search of the pdf shows that the word clathrate is never mentioned.
The paper briefly refers to hydrates, basically the same as clathrates.

44
Permafrost / Re: Arctic Methane Release
« on: May 23, 2017, 11:25:37 PM »
Made a video based on recent Shakhova study and the recent review on hydrates (both 2017)

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Feedback is welcome, thanks.

45
Permafrost / Re: Arctic Methane Release
« on: May 23, 2017, 07:42:41 PM »
Possibly OT


Are the seepages off Svalbard possibly of a-biotic origin?


I believe it was near Svalbard where a Swedish team located hydrates in a region where biotic methane was deemed an impossibility. I look at seepage near the Mid-Atlantic Rift as possibly very different from ESAS, continental shelf, or delta seeps.


Terry
Related study NEW SOURCE OF METHANE DISCOVERED IN THE ARCTIC OCEAN
Quote
“It is estimated that up to 15 000 gigatonnes of carbon may be stored in the form of hydrates in the ocean floor, but this estimate is not accounting for abiotic methane. So there is probably much more


https://cage.uit.no/news/new-source-methane-discovered-arctic-ocean

The origin, source, and cycling of methane in deep crystalline rock biosphere
My summary, input is welcome...
Quote
There are two main routes for geological methane generation, organic (thermogenic), and inorganic (abiotic, meaning non-living). Thermally generated methane, is referred to as thermogenic, originating from deeper sedimentary strata. Thermogenic methane (CH4) formation occurs due to the break-up of organic matter, forced by elevated temperatures and pressures. This type of methane is considered to be the primary methane type in sedimentary basins, and from an economical perspective the most important source of natural gas. Thermogenic methane components are generally considered to be relic (from an earlier time). Generally, formation of thermogenic methane (at depth), can occur through organic matter break-up, or organic synthesis, both ways can involve microorganisms (methanogenesis) but may also occur inorganically. The involved anaerobic and aerobic processes can also consume methane, with and without microorganisms.The more important source of methane at depth (crystalline bedrock) is abiotic. Abiotic means that the methane formation took place involving inorganic compounds, without biological activity, magmatic or created at low temperatures and pressures through water-rock reaction


The abstract
Quote
The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments.

This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock.

Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4505394/

It is unclear to me what the authors mean with "the more important source of methane" (abiotic). Abiotic seems to originate from deeper in the crust?

46
Permafrost / Re: Arctic Methane Release
« on: May 23, 2017, 06:28:47 PM »
All that was said was the contribution to the releases of methane subjected to microbial oxidation was higher than had been previously suspected...

Can you please quote the part of the study which makes this point? Thanks.

Or is it this:
Quote
Shakhova et al. (2010b) have shown that CH4 concentrations in the ESAS water were anomalously high (up to 500 nM) compared to CH4 values generally observed in ocean waters (∼ 5 nM, Damm et al., 2008). Vigorous bubbling events (1.5 to 5.7 bubbles per second) were observed at some sites (Shakhova et al., 2013) as well as seepages of thermogenic CH4 (Cramer and Franke, 2005) indicating that part of the water column supersaturation likely results from a seabed source.

Bussmann (2013) has investigated the distribution of CH4 in the estuary of the Lena, one of the largest Russian rivers draining into the ESAS. They reported high CH4 concentrations (up to 1500 nM) in the river and in the creeks draining from permafrost soil and a strong decrease in the Buor-Khaya Bay (down to 26–33 nM). They concluded that the CH4 contained in the rich waters of the river was, for the most part, not reaching the marine waters, but that it was released by diffusion into the atmosphere before reaching the bay. A large water source is therefore unlikely to explain the CH4 saturation we observe in the ESAS coastal waters

Related
Predicting the fate of methane emanating from the seafloor using a marine two-phase gas model in one dimension (M2PG1) - Example from a known Arctic methane seep site offshore Svalbard
Quote
This work presents the model's first application in an Arctic Ocean environment at the landward limit of the methane-hydrate stability zone west of Svalbard, where we observe substantial methane bubble release over longer time periods.
http://adsabs.harvard.edu/abs/2017EGUGA..19.7004J

Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden
Quote
Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5322355/

Gas Hydrate Breakdown Unlikely to Cause Massive Greenhouse Gas Release https://www.usgs.gov/news/gas-hydrate-breakdown-unlikely-cause-massive-greenhouse-gas-release

Open access paper, recommended reading http://onlinelibrary.wiley.com/doi/10.1002/2016RG000534/full

This last study does not mean that methane buildup specifically in the unique geological ESAS region under sea-ice and penetrated permafrost, couldn't release larger amounts. Thus, it remains
Quote
Our results show that thawing subsea permafrost of the ESAS emits CH4 with an isotopic signature that cannot be easily distinguished from Arctic wetland emissions when looking only at stable isotope data. This similarity might complicate recent efforts to quantify Arctic CH4 source strengths on the basis of isotopic- and back-trajectory analysis of atmospheric CH4. Further in situ work is necessaryspecifically on the isotopic composition of CH4 in gas bubbles that reach the atmosphere – to better quantify the contribution of the ESAS to the global methane budget.

47
Permafrost / Re: Arctic Methane Release
« on: May 23, 2017, 03:29:16 PM »

Also interesting
Quote
..anthropogenic nuclear contribution, e.g. from nuclear waste buried in the coastal permafrost, is the most likely explanation for these elevated radiocarbon levels.

48
Arctic background / Re: Dark Snow
« on: May 22, 2017, 03:55:58 PM »
Funding The Dark Snow Greenland Operation in 2017
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http://darksnow.org/support

49
Greenland and Arctic Circle / Re: Greenland 2017 melt season
« on: May 22, 2017, 03:53:41 PM »
In retrospect (and to give some background information), this was just released last week

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50
Consequences / Re: Seed Bank Vault Flooding
« on: May 20, 2017, 07:06:33 PM »
Made a video

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