Arctic Warming and Destabilization of Gas Hydrates

Chris R. German, Geology & Geophysics
Richard Camilli, Applied Ocean Physics & Engineering
Dana Yoerger, Applied Ocean Physics & Engineering


Arctic Research Initiative
2010 Funded Project

Methane is a potent greenhouse gas (about 26 times more effective than CO2 ) that is estimated
to contribute ~15% to current global warming. In the Arctic, the issue of release of methane
from the seabed is particularly worrying because recent studies have suggested that warming of
the ocean by as little as 1°C could lead to significant destabilization of shallow shelf-edge gas
hydrates, and associated methane release, posing a particular threat to regional or even global
ecology. While the fate of gas hydrates in the Arctic is becoming a topic of focused international
research, however, methods of investigating the fate of the methane released remain poor. Even
answering such a simple question as: Does methane exiting the seafloor escape to the surface
ocean and atmosphere or is it dispersed laterally into the ocean interior? is proving problematic.
In this study, therefore, we aim to take up an invitation from our EC colleagues to join their 2-
week research cruise in Summer 2010 to investigate gas hydrate destabilization and seafloor
methane release at a particularly relevant natural laboratory: the Haakon Mosby mud volcano
(HMMV). The particular goal of our stand-alone WHOI project, within the larger EC program,
will be to fill an important technological gap using a combination of our free-swimming
(autonomous) underwater vehicle Sentry and a new sensor which we have developed that can
measure methane and other hydrocarbons in situ in the ocean, called TETHYS.

As well as representing a new marriage of the latest WHOI technologies, what is also innovative
about this project is that we will adopt lessons learned from our earlier deep-sea hydrothermal
work, carried out far from land on Mid-Ocean Ridges, to establish new methods for investigating
gas hydrates and associated methane release – methods that can be used in more widespread
investigations, in future, not just throughout the Arctic but along all the world’s ocean margins.

Our project will comprise three components:-
a) Detailed mapping and imaging of the HMMV to identify all sites of active methane
release and better understand the geologic controls of fluid flow.
b) Complete characterization of the unique “chemosynthetic” ecosystems that are fuelled by
methane released from the HMMV seafloor and which differ, spatially, across the surface
of the mound (“chemosynthetic” refers to the unusual nature of certain, rare, deep-sea
ecosystems that thrive on energy released from the Earth’s interior rather than the more
typical “photosynthetic” – sunlight fuelled - life).
c) 3D mapping of methane dispersed to the overlying ocean including in situ determination
of both methane concentrations in plumes rising above and away from the surface of the
mound and the speed and direction with which that material is dispersed.

Finally, an important aspect of our proposal is that it will establish new and strong collaborations
between WHOI researchers and European colleagues investigating the Arctic Ocean through two
related programs – ESONET, which is dedicated to establishing a series of ocean observatories
encircling the European Margin (of which the HMMV site is just one) and HERMIONE: Hotspot
Ecosystem Research and Man’s Impact on the Ocean.