An approved team for ocean research: the German research vessel MARIA S. MERIAN and the submersible JAGO. Photo: JAGO-Team, GEOMAR |
West
of Spitsbergen methane gas is effervescing out of the seabed. Is this
an indication that methane hydrates in the seabed are dissolving due to
rising temperatures? And what would the effects be? An expedition with
the German research vessel MARIA S. MERIAN and the submersible JAGO lead
by GEOMAR | Helmholtz Centre for Ocean Research Kiel hopes to help
answer these questions. The expedition begins today in Reykjavik.
The
average temperatures of the atmosphere are rising; the average
temperatures of the oceans, too. Not only living organisms react
sensititvely to these changes. The transitional zones between shallow
shelf seas and the deep sea at continental slopes store a huge amount of
methane hydrates in the sea bed. These specific, ice-like compounds
only forms at low temperatures and under high pressure. When the water
temperature directly above the sea bed rises, some of the methane
hydrates could dissolve and release the previously bound methane.
“This
scenario incorporates two fears: Firstly that enormous amounts of this
very powerful greenhouse gas will be released into the atmosphere, and
secondly that the continental slopes may become unstable” explains the
geophysicist Professor Christian Berndt from GEOMAR | Helmholtz Centre
for Ocean Research Kiel. He is leading an expedition starting today on
the German research vessel MARIA S. MERIAN which will analyse the sea
off the western shore of Spitsbergen in order to find out whether the
first methane hydrates in the sea bed are dissolving and what the
consequences might be.
The
expedition builds on research conducted by marine scientists from Kiel
who worked in this area of the sea in 2008. Back then they found over
250 places where gas was escaping the sea bed.
“These
spots lie directly on the border of the area of stable hydrates”
explains Professor Berndt. “Therefore we presume that the hydrates are
dissolving from the rim inwards.”
During
the upcoming expedition, the scientists from Kiel will be working
together with colleagues from Bremen, Switzerland, Great Britain and
Norway to discover whether the gas emanation shows signs of dissolved
hydrates and whether this is due to warmer sea beds.
With
the help of echo sounders, researchers will seek out new gas sources in
order to determine the total amount of escaping gas. With Germany’s
only submersible JAGO, they will closely investigate the gas outlets in
up to 400 m depth.
“It
is interesting for us, for example, to find out whether special
microorganisms that can break down the methane before it is released in
the atmosphere have settled around the outlets” explains Professor Tina
Treude from GEOMAR, who will be running the microbiological work during
the expedition.
Parallel
to this, geophysicists, lead by Professor Sebastian Krastel from
GEOMAR, will investigate the slopes under the gas outlet spots for signs
of instability using acoustic and seismic methods.
“The
methane hydrates act like binding cement on these slopes. If they
dissolve, chances are that parts of the slopes will slide,” explains
Professor Krastel, who focuses on marine hazards at GEOMAR.
“Overall
the program on this trip is very extensive. Now let us hope that the
weather will play along so that we can conduct all planned tests,” says
the head of the expedition Christian Berndt shortly before the departure
to Iceland.
Source: GEOMAR
