[tt] methane hydrate gasification

[Eugen Leitl]

(hmm part XXVII)

Exhibit 1:
http://www.celsias.com/article/methane-begins-erupt-arctic-permafrost/

Exhibit 2:
http://en.wikipedia.org/wiki/Permian-Triassic_extinction_event#Methane_hydrate_gasification

Methane Begins to Erupt From Arctic Permafrost

In what sounds like a scene from a Hollywood disaster film, scientists looked
over the side of the Russian research vessel Yacob Smirnisky to view the
ocean foaming as huge ancient deposits of methane, a greenhouse gas 20 times
more potent than carbon dioxide, began to thaw and bubble to the surface. The
alarming reports of what the International Siberian Shelf Study 2008   have
been witnessing over the last few days were sensationally revealed   by
Britain's Independent Newspaper two days ago (23rd September 2008). As the
newspaper reports this is the first evidence that millions of tons of methane
are beginning to be released into the atmosphere from beneath the Arctic
Ocean.

The intense concentrations of the greenhouse gas, some up to 100 times
background levels, were discovered in the East Siberian Sea and the Laptev
Sea, an area some tens of thousands of square miles in the Siberian
continental shelf. The Independent published extracts from emails sent from
one of the lead researchers aboard the Yacob Smirnisky, Orjan Gustafsson of
Stockholm University:

"We had a hectic finishing of the sampling programme yesterday and this past
night," said Dr Gustafsson. "An extensive area of intense methane release was
found. At earlier sites we had found elevated levels of dissolved methane.
Yesterday, for the first time, we documented a field where the release was so
intense that the methane did not have time to dissolve into the seawater but
was rising as methane bubbles to the sea surface. These 'methane chimneys'
were documented on echo sounder and with seismic [instruments]."

Massive stores of methane, which formed before the last ice age, are locked
away beneath the permafrost of the northern hemisphere. Produced naturally by
the decay of water-logged vegetation, over millennia the methane deposits
have accumulated beneath the land and ocean, removing huge quantities of
carbon from the atmosphere. Permafrost at the sea floor had acted like a lid
to prevent the huge methane deposits, from escaping. It's thought that this
new phenomena is related to the rapid warming that the Arctic region has
experienced in recent years.

As Gustafsson wrote:

"The conventional thought has been that the permafrost 'lid' on the sub-sea
sediments on the Siberian shelf should cap and hold the massive reservoirs of
shallow methane deposits in place... We have found elevated levels of methane
above the water surface and even more in the water just below. It is obvious
that the source is the seabed." 

Methane is a short lived greenhouse gas, remaining in the atmosphere for
about 12 years compared to the 100 years of carbon dioxide. However, the
danger comes from the fact that methane is about 20 times more potent than
carbon dioxide at trapping solar radiation. Scientists have long warned that
the release of these massive deposits of methane could create a huge
"positive feedback mechanism." The methane released from beneath the
permafrost could increase temperatures, melting the permafrost faster,
releasing even more methane, and so on. It is feared that such a scenario
would accelerate Global Warming to the point where nothing mankind could do
would reverse the problem.

Scientists believe that similar releases of methane in the past, so called
"methane burps", have caused rapid and severe increases in global
temperatures, dramatic climate change and mass extinctions. Methane levels in
the atmosphere had risen steadily since the industrial revolution only to
level out in recent times. Then in 2007 a rise in global methane levels was
recorded. At the time researchers were unsure if this was the beginning of a
trend.

methane graph

With these latest revelations, it seems that another rise in global methane
levels is set to be recorded this year. The extreme loss of Arctic sea ice
seen in recent years could aggravate the problem further as the darker seas
warm faster than the ice, which had reflected vast amounts of solar radiation
back into space. The question is this; how will the world respond to what is
undoubtedly a disaster in progress? At a time when our attention is focused
on the turbulence in the world's economic markets will we continue to ignore
the warnings of science? "Nobody knows how many more such areas exist on the
extensive East Siberian continental shelves," according to Dr Gustafsson.

The findings of the International Siberian Shelf Study 2008 will be published
in the American Geophysical Union  . The team have been recording their
course on Google Maps  .