This is very interesting in two ways:
1. The threat that trawling might disrupt the biolayer that oxidises
methane. The existence of this effect surely needs to be researched. It
may be that the biolayer actually recovers quickly following a trawl. It
may even be that trawling increases nutrient availability and enhances
the oxidation. Or maybe not. We need to know the answer!
2. This also offers an opportunity for a very low impact form of
geo-engineering - to enhance the ability of the biolayer to oxidise the
methane, maybe maybe by adding nutrients where they are limiting. Again,
this needs to be researched!
Oliver Tickell.
On 14/05/2011 10:24, John Nissen wrote:
>
> Hi all,
>
> Thanks Albert and thanks to Michael before you (about the trawling danger).
>
> Albert, the problem of the ESAS (East Siberian Arctic Shelf) is that
> it's shallow - about 8 metres deep I believe - so the microbes in the
> water do not have time to convert the methane rising from the seabed.
> Any overturning of the water column makes things worse, because it
> carries warmer water from the surface to the seabed, to melt the
> permafrost. But certainly an adequate supply of nutrients would help the
> microbes in the water. What about the microbes on the seabed - in the
> "biotic" layer that Michael mentions? Presumably they convert methane
> before it enters the water above the biotic layer. Is there any way to
> stimulate their activity?
>
> If venting were done deliberately, could there be a way of capturing the
> methane, with or without the CO2?
>
> Michael, I'm copying this to Professor Watson, representing DEFRA, to
> alert about the trawling danger. There obviously needs to be some
> effective international regulation to protect areas of the sea-floor
> where there may be a biotic layer of methane-converting microbes.
>
> John
>
> ---
>
> On 13/05/2011 18:50, Veli Albert Kallio wrote:
>> The methane tends to be devoured by microbes. However, methane supply
>> may exceed availability of other necessary nutrients such as oxygen
>> and trace elements that living organisms require. Thus there is a
>> saturation point where methane conversion to carbon dioxide stops,
>> after this the methane dissolves into water as such.
>>
>> As a result, it is very dangerous situation if a still deep water
>> pocket becomes heavily laden with carbon dioxide as this dissolves in
>> huge volumes (5 times the volume of water). The water column becomes
>> highly unstable if water overturns and the dissolved carbon dioxide
>> and methane starts runaway nucleation as the rising bubbles pull water
>> with them upwards. This leads to overturning of water and suffocating
>> discharges of carbon dioxide and methane as well as risk of drowing
>> where ocean turns into foam and becomes unsupportive to boats. Over
>> 2,000 people died and professor Michel Halbwachs was commissioned to
>> resolve this by a controlled venting of gases.
>>
>> The largest singel pan of highly dangerous carbon dioxide and methane
>> laden water is Lake Kivu. Besides melting permafrost thawing methane
>> clathrates, volcanoes can pump methane and carbon dioxide into water
>> making it unstable, which has been so far with the case Professor
>> Halbwachs team of engineers has been working to resolve to prevent
>> further fatalities. We will see these in off-shore and on-shore water
>> bodies that have presence of frozen methane. Microbes will eat methane
>> away in most cases, but when supply of other nutritiens falls back
>> methane accummulates after microbial digestion to carbon dioxide
>> phases out.
>>
>> I hope this clarifies what happens to the methane and carbon dioxide
>> as arctic reservoirs start leaking it.
>>
>> Yours sincerely,
>>
>> *Veli Albert Kallio
>> *
>> ------------------------------------------------------------------------
>> Date: Fri, 13 May 2011 11:39:59 +0000
>> Subject: Re: [geo] Arctic Council meeting on Thursday - the truth is out
>> From: [log in to unmask]
>> To: [log in to unmask]
>> CC: [log in to unmask]; [log in to unmask];
>> [log in to unmask]; [log in to unmask];
>> [log in to unmask]; [log in to unmask]; [log in to unmask];
>> [log in to unmask]; [log in to unmask];
>> [log in to unmask]; [log in to unmask]; [log in to unmask];
>> [log in to unmask]
>>
>> Hi Folks,
>>
>> Your question "There could also be an effect of methane bubbling
>> through water on marine life. Anybody know?"
>>
>> I don't know about health effects on marine life at an expert level,
>> but....probable little...if any. However, Please pay attention to
>> this........
>>
>> http://www.afma.gov.au/resource-centre/teachers-and-students/about-fishing-methods-and-devices/trawl/demersal-trawl/
>>
>> This is the type of commercial fishing gear you can expect going into
>> new arctic areas. The Demersal trawling gear drags along the seabed
>> and basically will wipe out and kill every thing in it's path. If this
>> happens in a hydrate field, critical damage to the methane oxidizing
>> biotic layer will happen. It was a trawler that found the Cascade
>> Hydrate field. The sea-floor biotic layer can oxidize up to 90% of the
>> methane. I don't think we need to loose that type of protection.
>>
>> Also, this type of fishing boat wiped out the north Atlantic cod and
>> is now making a big dent in the north pacific stock. They work the
>> continental shelves. So, don't underestimate what they can do to a
>> hydrate field. And, expect them to cheat if they are limited to only
>> mid water gear. It is very easy to switch gear with few knowing about
>> it. I have watched a number of shady practices in that business. They
>> need to be banned from any known or suspected hydrate fields and
>> probably the arctic as a whole. Fish-n-Chips are not worth it.
>>
>> Thanks
>>
>> Michael
>>
>> On May 12, 2011 11:30pm, John Nissen <[log in to unmask]> wrote:
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > Dear Professor Watson,
>> >
>> >
>> >
>> > http://news.bbc.co.uk/1/hi/programmes/newsnight/9483790.stm
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > How absurd. Now we have it confirmed that the Arctic Council is
>> > there, not to pretect the Arctic, but to carve up the resources.
>> > And now we know that the people involved ARE rubbing their hands
>> > with glee as the sea ice retreats, seemingly oblivious of the
>> > tremendous horrors that await them (and the rest of humanity) as
>> > Arctic ice melts away and methane, trapped by permafrost, is
>> > discharged in ever increasing quantities to exacerbate global
>> > warming. There are signs that this process is already underway
>> > [1]. As I said to BBC correspondent, Richard Black, at the EGU
>> > conference in April, we only need 10% of potential methane to be
>> > discharged over 20 years, and the rate of global warming would be
>> > multiplied by about 40 times [2]. This is easily enough to cause
>> > abrupt and catastrophic climate change [3].
>> >
>> >
>> >
>> > Governments around the world, together with the whole environment
>> > movement, should unite to fight this absurd situation, and back a
>> > plan to stop the methane at all costs. This is an emergency.
>> >
>> >
>> >
>> > Kind regards,
>> >
>> >
>> >
>> > John
>> >
>> >
>> >
>> > [1] http://news.bbc.co.uk/1/hi/8437703.stm
>> >
>> >
>> >
>> > [2] Sam Carana points out that I was erring on the low side for
>> > this figure.
>> >
>> >
>> >
>> > [3] I am not the first to point out this danger from methane.
>> > Research on the East Siberian Arctic Shelf (ESAS) has exposed the
>> > dire situation.
>> >
>> >
>> >
>> > If just one percent of ESAS methane escapes its crystal prison,
>> > Semiletov suggested at a geophysical conference in 2008, it might
>> > push
>> > total methane to 6 parts per million. Some researchers consider
>> > this is
>> > a tipping point towards ‘runaway climate change.’ If that term
>> > doesn’t
>> > summon up an image, you can take NASA scientist James Hansen’s
>> > suggestion of an “ice-free state” where the Greenland and
>> > Antarctic ice
>> > sheets melt entirely, raising global sea level by over 200 feet.
>> >
>> >
>> >
>> > See http://tyeebridge.com/?p=608
>> >
>> >
>> >
>> > ---
>> [snip]
--
--
Oliver Tickell
e: [log in to unmask]
p: +44 1865 728118
a: 379 Meadow Lane, Oxford OX4 4BL, UK.
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