2011-12-21 18:29:31Twelve questions for Drs Shakhova and Semiletov
John Mason

johntherock@btopenworld...
86.142.20.0

OK, having contacted this team at last, I have produced twelve draft questions, incorporating those sent to me by Dan. I'll draft some background (quick explanation of how methane occurs beneath/in permafrost and why it is submerged in this case). The team will not be back in the office until early January so we have a little time to think about this. I've worded the draft questions to try to draw from them:

a) what is going on;

b) is it unprecedented within the observational record and why;

c) is it representative of the East Siberian Arctic Shelf in general or do large areas remain unmapped;

d) is talk of huge multi-gigatonne methane burps alarmist or realistic;

e) if they see the potential for massive releases, in what timeframe could this risk materialise?

I think the consequences of a massive-scale methane release are within our realm of knowledge to deal with - the questions should IMO be entirely focussed on the field area in which the team have been working: in terms of hands-on experience these guys have a lot!

Anyway: the draft questions - please hack to pieces!

Questions for Shakhova & Semiletov

1) Methane can occur in a submerged permafrost setting both as hydrate (clathrate) deposits and in the gaseous form. In the case of the ESAS, which form do you view to be predominant and do your data allow an estimate of the relative proportions?

2) How much methane are we talking about in total?

3) The ESAS is an extensive shallow sea, less than 50m deep. In the specific case of its methane hydrate deposits, what is the minimum depth beaneath the seabed at which they can stably occur?

4) Your 2011 field season is reported to have discovered kilometre-diameter plumes of outgassing methane. Are these located in areas visited in previous seasons?

5) If the answer to 4 is yes, what magnitude of change was observed in 2011 compared to previous years?

6) How much of the ESAS remains to be mapped with respect to sites of outgassing?

7) With respect to the outgassing observed in areas mapped in 2011, does the evidence point to methane escape via talik channels and if so how have these developed; if not what is the alternative mechanism?

8) Is the outgassing methane thought to be due to simple release of physically-trapped gas or due to methane hydrate destabilisation, or both: can the sources in fact be distinguished?

9) Do those outgassing sources have the capacity to add sufficient methane to the atmosphere to bring about abrupt climate change?

10) If the answer to 9 is yes, how might this occur, given that there is talk elsewhere of sudden methane "burps" of up to 50Gt - does that seem feasible to you?

11) If the answer to 9 is yes, what sort of timeframe are we looking at - years, decades or centuries?

12) What field research objectives are planned for 2012 and the coming years on the ESAS?

 

Cheers - John

2011-12-22 14:44:31
Agnostic

mikepope_9@hotmail...
118.208.149.13

In relation to the 12 draft questions proposed above, I make the following comments:

Q1.  They have already reported estimates of CH4 in clathrate 1,000 gigatonnes, in gaseous form 700 gigatonnes and in permafrost 500 gigatonnes. 

These refer to Continental Shelf CH4 and exclude on-shore deposits which others have variously estimated as 1,000 – 2,000 gigatonnes.

What is not clear is if methane held in permafrost is deemed to be in the form of yedoma emitting CH4 on thawing or biota which could emit CH4 when bacterial action becomes possible due to retreat of permafrost and establishment of an active zone.  Biota sourced emissions are very difficult to estimate.

 

Q2.  On the basis of the figures noted above, 2,100 gigatonnes but this does not appear to include an estimate of CH4 sourced from biota – an estimate which may of course not be available (?)

 

Q3.  In their 2007 Paper, they report presence of clathrate at depths of 20 – 200 metres beneath the seabed of the ESAS and account for its stability at such shallow depth as being due to the presence of covering impermeable permafrost capping.

It might be interesting to ask for confirmation of this and the role played by gaseous CH4 in assisting to maintain shallow clathrate stability which depends on both temperature and pressure.

 

Q8.  Is it possible to identify the source of CH4 emissions?  Possibly from carbon isotope signature?  Is there other evidence of destabilization of shallow clathrate?

 

Q9.  Given the estimated quantities of CH4 contained in the form of clathrate, gas and permafrost, the answer to this question must surely be: Yes.

 

Q10.  A 50 gigatonne burp?  Quelle horreur! 

How certain are they that sudden emission of 3.5 gigatonnes would precipitate sudden climate change?

Is it more likely that emissions would build-up over time, rather than be sudden and devastating?  Are either abrupt or gradually increasing emissions considered likely this century?  Have estimates of the volume of possible emissions been made?

 

Q13.  What proposals have been made for continuous monitoring of the Continental Shelf, particularly the ESAS and are these likely to be implemented and if so, when?

 

Just a few thoughts.  I imagine that responses to questions will form the basis for an interesting SkS post after the good Doctors have approved it.  Hope they will also respond to comments.

2011-12-22 17:47:32
John Mason

johntherock@btopenworld...
86.142.20.0

Some good points there - it is important not to waste this opportunity by asking them questions whose answers are already in papers they have had published!

I'll try and read/re-read all the relevant material over the Xmas break to minimise the chance of that happening. In the meantime I've done some more investigations....

WRT the 50 gigatons figure, this is problematic. It appears in the brochure of the Arctic Methane Emergency Group which apparently formed after the recent AGU meeting: see http://www.arctic-methane-emergency-group.org/ (flash site - yuk!). The brochure may be downloaded as a 10mb PDF from the link on the LHS of the homepage there - click on "Printed booklet".

Methane  is  stored  as  hydrates  in  the
Arctic  and  sub-Arctic  and  in
surrounding permafrost. 1672Gt (1Gt =
1  billion  tons)  of  methane  is  stored
under  terrestrial  permafrost  alone,
twice  the  current  atmospheric  content
of  carbon  [4].  Ongoing  observations
and analysis forecast a similar amount is
held  in  sub-sea  stores.  As  undersea
permafrost  thaws  it  releases  the  stores
of  ‘free’  gas  (or  methane  hydrates)
hidden  beneath  it.  A  sudden  50Gt
release  is  deemed  increasingly  “highly
possible” [5].

Following reference 5 takes you to: http://www.nsf.gov/news/news_summ.jsp?cntn_id=116532

No such figure is given in this reference. The only thing remotely close is:

"The release to the atmosphere of only one percent of the methane assumed to be stored in shallow hydrate deposits might alter the current atmospheric burden of methane up to 3 to 4 times," Shakhova said. "The climatic consequences of this are hard to predict."

1% would be in the 15-20Gt range.

The "brochure" increasingly appears to be a rather sloppy piece of work, a victory of presentation over content. I'm surprised the deniers are not all over it. However, it is not the work of Shakhova/Semiletov.

Regardless of that - and perhaps we should criticise it as well as giving S&S's responses a verbatim airing -  the potential seriousness of the situation up on the ESAS is worthy of detailed examination. Let's pull out the stops on this one and try our best to get to the bottom of what is actually known. I'll come back after Xmas with a bullet-point list of the established facts..... and a second list of known unknowns!

Cheers - John

 

 

2011-12-22 18:09:49
John Mason

johntherock@btopenworld...
86.142.20.0

Thanks also to Michael Pope who has just emailed be a Dec 2010 presentation by Shakhova/Semiletov to add to the growing heap of Xmas reading!!

Cheers - John

2011-12-22 20:34:47
John Mason

johntherock@btopenworld...
86.142.20.0

Well I have solved the 50 GT mystery. It was crap referencing in that brochure.

It's here: http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

Paragraph in question:

The total area of submarine permafrost within the Siberian Arctic shelf is estimated
to be more than one and half million square kilometers. Amount of methane hydrate
deposited beneath and/or within submarine relic permafrost is estimated to be at least
540 Gt. Amount of free gas, accumulated beneath the hydrate deposits, is expected to
be about 2/3 of the amount of hydrates or 360 Gt. Additionally as much as 500 Gt of
carbon could be stored within as minimum as a 25 m-thick permafrost body of this
type. The total value of ESS carbon pool is, thus, not less than 1,400 Gt of carbon.
Since the area of geological disjunctives (fault zones, tectonically and seismically
active areas) within the Siberian Arctic shelf composes not less than 1-2% of the total
area and area of open taliks (area of melt through permafrost), acting as a pathway for
methane escape within the Siberian Arctic shelf reaches up to 5-10% of the total area,
we consider release of up to 50 Gt of predicted amount of hydrate storage as highly
possible for abrupt release at any time. That may cause ∼12-times increase of modern
atmospheric methane burden with consequent catastrophic greenhouse warming.

Cheers - John

2011-12-22 23:54:39
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Some interesting perspectives and summations (from a journalist's POV):

http://www.cjr.org/the_observatory/methane_mysteries.php

2011-12-23 00:15:39
John Mason

johntherock@btopenworld...
86.142.20.0

Indeed, Dan: I came across that a couple of hours back and it's worth everyone reading.

I've asked John Abraham/Scott Mandia if they could obtain some "rapid responses" from RF experts to the warming consequences of the hypothetical scenario of a 50GT methane burp getting mixed-into the system. At this time of year the "rapid response" won't happen immediately, but it'll be interesting to see what is forthcoming. The justification for the scenario itself needs to be a key part of the questions submitted to S&S. As to effect, I would kinda imagine a more prolonged 1998-style warming-spike (bigger, maybe) with a residue of ~1.5 years' anthro-CO2 being added all at once when the residency time for the methane has passed, but that is considering it in isolation and ignoring other potential releases that could follow. This 50GT figure is clearly a worst-case scenario but it needs to be considered as it has appeared in an abstract. Cue deniers in 2025 saying "the past 7 years have shown a cooling trend"........

More as I get it....

Cheers - John

2011-12-23 09:50:39
Agnostic

mikepope_9@hotmail...
118.208.149.13

.... the warming consequences of the hypothetical scenario of a 50GT methane burp getting mixed-into the system.

That rather depends on the Global Warming Potential value used for CH4, and over what time-line, doesn't it?  For example, many Papers cite a GWP of 20-25 which is of course perfectly valid - over a 100 year time line.  But CH4 usually oxidises to CO2 in the atmosphere over an 8-12 year period and over this period the GWP of CH4 is >72.

2011-12-23 20:06:38
John Mason

johntherock@btopenworld...
86.142.20.0

Latest on this is that Scott Mandia has put me in touch with Mandy Joye who is also involved in this work.

Going off for Xmas tomorrow with a sheaf of papers to read/take notes from. Hopefully SkS can in due course offer the definitive account on this research.

Agnostic - indeed - it's powerful over short timescales. Where the uncertainty seems to exist is whether the concentration simply spikes and that's it or whether repeated pulses keep topping the methane content up.

Cheers - John

2011-12-23 20:16:05
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.255.72

Good work John M. It'll be interesting to see if there's any meat on the bones of this story.

2011-12-24 06:53:39
Andy S

skucea@telus...
173.183.12.188

There's a new NYT article out by Justin Gillis on this subject. It's odd that few of the  "senior scientists I [Gillis] spoke with"  seem prepared to go on the record. Perhaps this is just professional reticence.

In case John M and others don't have enough reading over the holidays, here are some links to some relevant articles I have found.

Geology of the East Siberian Shelf (Franke and Hinz)

Structure of the Russian Arctic Shelf (Vinogradov et al) (Follow link to get pdf)

Seismic evidence for premafrost under the Laptev Sea (Hinz et al)

East Siberian shelf perma frost (Danilov et al)

Modelling subsea permafrost in the ESS (Nicolsky and Shakhova) (Looks interesting, I haven't read this yet)

Near surface permafrost degradation (Delisle)

Subsea permafrost and gas hydrates Laptev Sea (Delisle)

 

If anybody wants a copy of the recent Dmitrenko paper, email me: agskuce@gmail.com

I'll have a think about some questions over the next few days.

This should be very instructive.

 

2011-12-24 07:01:56
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
24.213.18.68

Thanks for the links, Andy!

2011-12-24 17:45:44
John Mason

johntherock@btopenworld...
86.142.20.0

Thanks, Andy. It looks like we are the only group actually talking to the people on the ground WRT this one!

Cheers - John

2011-12-28 07:32:07
Andy S

skucea@telus...
173.183.12.188

Shakhova and Semiletov provide a comment at Revkin's

I find the observation about the unfrozen but apparently sub-zero core puzzling. I wonder, did the core melt while it was being taken, were the temperatures measured in the borehole or in the core, was the pore water in the core sediments saline, what does acoustic/seismic imaging of the seabed show at this location? I guess we'll soon be in a position to ask such questions.

2011-12-28 21:32:46
John Mason

johntherock@btopenworld...
86.133.60.255

Thanks for that link, Andy.

I have now read a heap of papers on this topic and there appears to be a convergence of opinion in the most recent ones. The problem with a rapid 50Gt release (suggested by S&S, 2008) is a mechanism for it to occur: nobody has provided one yet in terms of a one-off event (like the Storegga Slide which was on a phenomenal scale but which released ~1Gt). It is one thing to destabilise disseminated methane hydrate and another for it to quickly make its way up though a great overburden of sediment to the sea-floor and thence to the atmosphere. However, the ESAS is provided for in terms of tectonics with an abundance of active faults, which would represent zones of greater-than-usual permeability. It is quite possible that the most active degassing areas mark such fracture-zones. These may be tapping source areas deeper than the gas hydrate stability zone, of course. Tectonic activity being a typically sporadic affair, this raises the possibility that periods of major degassing occur/have occurred interspersed with quieter spells: thus a single years' data must be interpreted with caution. It is important to remember that this is an area which is still very data-poor, although it is common sense to note that modelling is always second-best to observation. However, sudden methane burps aside, there is potentially something very serious going on up there.

Another problem is that this is an area of the planet that has been seriously under-explored, with detailed year-on-year work only being done during the last decade.Anyhow, the questions are continuing to firm-up in my mind.

How to do this post? One approach I've started to consider is to do a two-parter: a summary of the most recent papers as a Part 1, with the interview to be posted as Part 2 to coincide with the official data-release in the Spring. Doing it this way might well get a far more detailed response from S&S if we agree with them not to post it until the very same day that they send out their findings. Good idea or bad idea? It would be good to know peoples' thought WRT this.

Another thing to think about is how the deniers are responding to this issue. If anyone spots a denialist theme, suggestive of any "official" lines that are being taken, please could they note them on this thread? That way, they can be very effectively countered in the post(s). Indeed if a two-parter is done then part one could sort out denier talking-points and can be a reference in discussion of part two if required.

Cheers - John

2011-12-29 05:39:13A plethora of methane hydrate papers
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

H/T to Artful Dodger:

http://scholar.google.com/scholar?q=related:x4cxaMTOWqEJ:scholar.google.com/&hl=en&as_sdt=0,5

2011-12-29 21:47:47
John Mason

johntherock@btopenworld...
86.133.60.255

Thanks for that Daniel. In the meantime, here are the five most recent papers I could get my hands on: the "take-homes" I have jotted down will be building-blocks for an introduction to the subject.

 

Dmikentro et al 2011 - Recent changes in shelf hydrography in the Siberian Arctic: potential for subsea permafrost instability

Take-home:

These authors confirm a significant (2.1C) warming of the bottom water layer of the ESAS since the mid-1980s. During this time the upper boundary of the subsea permafrost has deepened by ~1m. They attribute the anomalous methane areas as due to an ongoing steady degradation of the undersea permafrost that began when the ESAS was submerged 8000 years ago. However, they warn that continued warming is likely to lead to significant permafrost destabilisation within ca. 1000 years.


Biastoch et al, 2011 - Rising Arctic Ocean temperatures cause gas hydrate destabilization and ocean acidification

Take-home:

The risk of destabilization of gas hydrates due to global warming is acknowledged, especially in the Arctic, where inhomogenous but considerable change is occurring over shallow shelf areas where extra warming is provided by Atlantic inflow. 25% of the shallow and mid-depth regions containing gas hydrates are expected to be affected within the next 100 years, but the impact of limited methane release from these areas is not expected to be significant within that timespan.


Fisher et al, 2011 - Arctic methane sources: isotopic evidence for atmospheric inputs

Take-home:

Examination of carbon isotope ratios of air arriving at Spitzbergen in late summer 2008/2009 gives results indicative of a predominantly biogenic CH4 source, namely boreal wetlands. Samples taken in springtime (when said wetlands are frozen) gave results indicative of a larger influence from the gas-fields in the Ob river region. Although seabed emissions of CH4 have been observed on the Spitzbergen continental slope, none have yet been detected to have entered the atmosphere. The research illustrates the importance of wetland emissions, which have the potential to respond quickly and powerfully to sustained climate warming.


Isaksen et al, 2011 - Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

Take-home:

These authors note that the magnitude of and feedbacks from future Arctic methane release remain unknown and that there is a need for much-improved understanding within this field. They applied an atmospheric chemistry transport model to see what might happen: the model results were that large CH4 emissions would have a surprisingly large impact on the atmosphere with respect to its composition and radiative forcing properties. With specific reference to that part of the radiative forcing contributed by methane, they found that a methane emission increase by a factor of 2.2 (e.g. by a sudden hydrate-based release) would increase radiative forcing by ca. 250% - a powerful positive feedback indeed.


Shakhova et al, 2010 - Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic Shelf

Take-home:

Releasing just a fraction of the abundant sub-permafrost CH4 of the ESAS would trigger abrupt climate warming. Although it is widely believed that the permafrost keeps a lid on this gas source, they found in over 5000 observations that >80% of ESAS bottom waters and >50% of ESAS surface waters are supersaturated with dissolved CH4; the amount actually venting to the atmosphere is on a par with previous estimates of CH4 being released from the entire world's oceans. There needs to be progress in understanding the nature of these sedimentary CH4 sources and how they may respond to future warming: in particular, there is a need to establish whether this extensive CH4 venting is part of an ongoing process or it is the start of  a new, massive period of CH4 release.

 

To me, the points raised in these papers suggest a very fragmentary state of knowledge WRT the Arctic as a whole, but that the ESAS is an area of particular significance, especially since the work is observation-based. The situation can be divided into "known knowns" and "known unknowns":

Known knowns: Arctic bottom water over shallower areas has warmed significantly in recent decades; methane venting has been observed in several areas and especially over the ESAS; this methane is now reaching the atmosphere.

Known unknowns: whether the ESAS venting represents the discovery of an ongoing process that began when the ESAS was submerged or whether it is something new; whether it is coming from a gas source or a gas hydrate source and what is likely to happen next; whether an abrupt release of methane on a colossal scale is possible and how that may occur.

BTW, a good general background reading piece is David Archer's (2006) Destabilisation of Methane Hydrates: A Risk Analysis (PDF)

Cheers - John

2011-12-30 02:36:59
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Andy Revkin has now posted two follow-up posts about Arctic methane on his DOT Earth blog.

Leaders of Arctic Methane Project Clarify Climate Concerns posted on Dec 27, 2011

More Views on Climate Risk and Arctic Methane posted on Dec 28, 2011

2011-12-30 03:01:58
John Mason

johntherock@btopenworld...
86.133.60.255

Thanks John. The more I read around this the more I feel a two-parter is justified. Background followed by the interview. Do people agree with this view?

Cheers - John

2011-12-30 04:11:23John Mason
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Aye!

2011-12-30 04:20:31
John Mason

johntherock@btopenworld...
86.133.60.255

I'll get to work on it....... the draft will appear as a separate thread in this section.

Cheers - John

2011-12-30 05:36:43
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
24.213.18.68

"Do people agree with this view?"

Seconded.  Motion carried. :)

Thanks for taking a leadership role on this!

2011-12-30 05:53:22
John Mason

johntherock@btopenworld...
86.133.60.255

Someone has to! ;)

It'll take a fair time to get the background written up, and scrutinised/revised by people here. Have perhaps jumped the gun a little by emailing Shakhova with the suggestion that the interview is conducted in stages this next two months but released to exactly coincide with their official release they have been alluding to. This will be when the media set-to playing with it and the deniers determine and set forth their response. It makes great sense for that to be the time to have the latest on SkS - AND to figure out the likely denier response. Let's see if we can get ahead of the game on this one :)

Cheers - John

2011-12-30 07:03:53
Andy S

skucea@telus...
173.183.12.188

Here are some draft questions that I would like to ask. I realize that these overlap with or duplicate some suggestions made previously by others.

1. Have you done any sampling, chemical analysis and carbon isotope analysis of the fugitive gas to see if anything can be learned about its provenance (i.e., biogenic, thermogenic or destabilized hydrates) or the age of the organic matter the methane was originally derived from?

2. Do any of the observed methane seeps correlate with features seen on acoustic imaging of the sea bed (e.g., channels, taliks, pock marks, faults) or on deep seismic data (e.g., faults, anticlines, gas chimneys)?

3. In your JGR paper from 2010 you state that methane hydrates in Siberia can occur at depths as shallow as 20 m. Have any such shallow methane hydrates on the ESAS been observed or sampled? If so, how could hydrates have formed at such depths? Is there any evidence, for example, of Quarternary water depths significantly deeper than the present water depths on the ESAS?

4. The recent alarming reports of very large releases of gas on the ESAS prompt us to ask how  quickly these emissions could change global atmospheric methane concentrations in a detectable amount, for example, at Mauna Loa or other observatories?

[Tweaked on a later edit]

2011-12-31 11:03:26
Agnostic

mikepope_9@hotmail...
118.208.178.1

I too an puzzled by Dr Shakhova’s finding sediments in a 53 metre core to be completely thawed at sub-zero temperature – which casts doubts on the Dmikentro modeling. 

No less important is that at 53 metres, sediment is found to be thawed.  Was this finding in a fault area?  Is thawing attributable to geothermal heat rather than climate change influence – or both?

Nice summaries John Mason and I definitely agree with your 2 part approach, particularly an assurance to S&S not to publish before they do.

Good questions Andy S, much along the line of my own thinking.  Not just Mauna Loa we need to think of.  How will increasing presence of methane affect Arctic amplification - and future methane emissions?

2011-12-31 12:03:28
Andy S

skucea@telus...
173.183.12.188

Agnostic (and others): you maybe interested to read the reply by Dmitrenko to S&S's comments on their unfrozen core. Scroll down to the bottom of this Dot Earth post:

[S&S]“The model in the Dmitrenko paper [link] assumed a thaw point of zero degrees. Our observations show that the cornerstone assumption taken in their modeling was wrong. The rate at which the subsea permafrost is currently degrading largely depends on what state it was in when recent climate change appeared. It makes sense that modeling on an incorrect assumption about thaw point could create inaccurate results.”

[Dmitrenko]This assessment of the model we used is completely wrong! The model takes into account that water can remain unfrozen at temperature below 0 degrees – “…the simulated temperature of sediments down to 25 m is below 0°C (dark blue line in Figure 6). Note that the sediments can still remain unfrozen because of the salt contamination”, page 7, right column, first paragraph.

This comment by Dr. Semiletov clearly demonstrates that he even didn’t carefully read our paper. Figure 6 shows simulated temperature profiles below the seafloor as a function of depth with unfrozen sediments at temperature below 0°C in the upper 30 m layer.

He sounds a little peeved!

 

2011-12-31 12:36:41
Agnostic

mikepope_9@hotmail...
118.208.178.1

Thanks Andy.  Dmitrenko’s commet referred to the top 30 metres.  Is it quibbling to note that S&S refer to 53 metres?  And I note the explanation of thawed sediment at temperatures below zero is the presence of salt in the sediment.  Does the oresence of salt have that effect?  I think it will be an interesting debate between Dmitrenko and S&S.

2011-12-31 13:53:48
Andy S

skucea@telus...
173.183.12.188

Agnostic: I'm not sure what "oresence" means but here's a figure I found showing the freezing points of salt water. For reference, typical sea water is 35 ppm and, according to Dmitrenko, the bottom water on ESAS varies between 20-28 ppm, with fresher water in the shallower bits near the coast. Dmitrenko seems to have assumed (judging from his freezing point of about -0.6 degrees C) that water of about 10ppm has penetrated to around 30 metres below the seafloor. I would imagine that it would be easy to get deeper and more salty water penetration to 50 metres or more if you tweaked the assumptions about near surface geology.

2011-12-31 14:38:46
Agnostic

mikepope_9@hotmail...
118.208.178.1

Hmmm.  Perhaps Dmitrenko has some tweaking to do

2011-12-31 18:22:01
John Mason

johntherock@btopenworld...
86.133.60.255

I think the problem here is that it was assumed that extensive outgassing from the ESAS would not be an issue because modelling suggested it wouldn't be... nobody had looked though: they went, looked and found extensive outgassing!

Clearly there is some strong rivalry featuring in this tale, although that is not exactly a novel situation. Neither is the notion that observation beats modelling on all occasions.

I still believe the most important line of enquiry is to establish whether the degradation and outgassing is a brand new phenomenon - or not. This has yet to be accomplished - and I wonder how it could be? How can permafrost degradation be dated, if at all?

Cheers - John

2011-12-31 21:02:58Questions revised....
John Mason

johntherock@btopenworld...
86.133.60.255

OK, here are the revised questions, based on my reading-up, Andy's contributions and the discussion on here. Only ten now but I think they are a lot better focussed. I'm taking them to task on this 50Gt figure and leading on to point out that there appears to be no sign of any such occurrence in the ice-core record, but wondering what may have occurred further back in the Cenozoic - given that our climate is moving towards a pre-Quaternnary one then the more distant past probably has greater relevance to what is occurring at the moment.

1) In your JGR paper from 2010 you state that methane hydrate in Siberia can occur at depths as shallow as 20 m. Have any such remarkably shallow methane hydrate deposits on the ESAS been directly observed/sampled and if so, how could methane hydrate have formed at such depths?

2) Your 2011 field season is reported to have located kilometre-diameter plumes of outgassing methane. Are these located in areas visited in previous seasons?

3) If the answer to 2 is yes, what magnitude of change was observed in 2011 compared to previous years?

4) Have you done any analyses/isotopic studies of the fugitive gas to see if anything can be learned about its provenance (i.e., biogenic, thermogenic, destabilized hydrate or a combination of these)?

5) Do the observed methane outgassing sites tend to correlate with features seen on acoustic imaging of the sea bed (e.g. taliks, pock marks, fractures) or on deep seismic data (e.g. fault-zones, anticlines and other structures)?

6) A critical question at this point is whether the outgassing is a recent development as a consequence of the dramatic Arctic warming of the past thirty years, or an ongoing, long-term response to the Holocene inundation of the ESAS. What are your thoughts on this and, on a similar line of enquiry, would it be possible to determine the age of the organic matter the methane was originally derived from?

7) The recent reports of substantial releases of methane on the ESAS prompt us to ask how these observed emissions could detectably change global atmospheric methane concentrations and in what timeframe?

8) With respect to future events, in your EGU 2008 abstract it is stated that "we consider release of up to 50Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time". This represents a colossal quantity of gas. How quickly could such a release occur and what would be the most likely mechanism?

9) A previous methane release of such a magnitude, occurring abruptly, would logically manifest as a spike in the global methane concentration record, yet the ice-core methane record has no such spikes during previous interglacials. Is there any evidence for massive methane release events having occurred further back - e.g. at any point during the Cenozoic?

10) How much of the ESAS remains to be mapped with respect to sites of outgassing and what field research objectives are planned for 2012 and the coming years?

 

Natalia is back in the office on January 4th so I'd like to get these questions finalised over the next few days if possible - thanks in advance!

Cheers - John

2012-01-02 13:54:06
Andy S

skucea@telus...
173.183.12.188

Looks good to me.

Perhaps include a link to the EGU 2008 abstract for the benefit of our readers. You could combine questions 2 and 3 into 2a) and 2b)

 


 

WUWT has found some easy targets opposing a recent statement by Semiletov and Shakhova

We would first note that we have never stated that the reason for the currently observed methane emissions were due to recent climate change.

With the following words taken from the title and beginning of their press release in March 2010.

Methane Releases From Arctic Shelf May Be Much Larger and Faster Than Anticipated

Thawing by climate change of subsea layer of permafrost may release stores of underlying, seabed methane

Illustration showing leakage of methane from the East Siberian Arctic Shelf.

Methane is leaking from the East Siberian Arctic Shelf into the atmosphere at an alarming rate.

If you read the two sets of comments closely they are not necessarily contradictory but it is all a bit misleading. Many commentators in the press and on blogs have understood S&S to have been saying that the observed methane releases were a result of recent warming.

I wonder if we should include a question aimed at sorting out this confusion. It might appear a little argumentative, however.

Added: here's another quote from a Q&A:

The subsea permafrost layer has long served as a barrier to the methane, sealing it in the seabed.  But warming waters have begun to melt this subsea permafrost. The result: destabilization and perforations in the permafrost that create pathways for releases of underlying methane.

2012-01-02 18:02:34
John Mason

johntherock@btopenworld...
86.133.60.255

Yes I will reference and link to the 2008 abstract among other key publications in the background I am preparing as Part 1. This will be a from-scratch introduction to permafrost/methane hydrates just so that anyone reading the interview can go to it and get everything they need from one page.

Question 6 could be tweaked to that effect. There is certainly some controversy here but I'm not especially surprised - for a start there seems to be some degree of professional rivalry between S&S and e.g. Dmitrenko. I still think pressing them wrt the 50Gt "abrupt release" is critically important (Q8/9), on the basis of "extraordinary claims require extraordinary evidence". Also it shows that SkS is equally skeptical when it comes to academic claims that have a dramatic ring to them - contrary to denier allegations.

I do wonder if S&S's comments would be clearer if English was their first language??

Cheers - John

2012-01-04 21:42:18
John Mason

johntherock@btopenworld...
86.133.60.255

Revised Question 6:

6) A critical question at this point is whether the outgassing is a recent development as a consequence of the dramatic Arctic warming of the past thirty years, or an ongoing, long-term response to the Holocene inundation of the ESAS. What are your thoughts on this and, on a similar line of enquiry, would it be possible to determine the age of the organic matter the methane was originally derived from?

The questions are now in Natalia's email inbox. I have asked her if  they know when any official announcement will be made this Spring, saying we would like to post the answers to coincide with that.

Now the only thing to do is get on with other stuff until a response is forthcoming!

Cheers - John