November 7, 2005
The Integrated Ocean Drilling Program (IODP) is an international
marine research drilling program dedicated to advancing scientific
understanding of the Earth by monitoring and sampling sub-seafloor
This IODP drilling expedition was operated by the
Joint Oceanographic Institutions (JOI) Alliance, comprised of JOI,
Texas A & M University, and Lamont-Doherty Earth Observatory of
IODP's initial 10-year plan is primarily
supported by two lead agencies, the U.S. National Science Foundation
and Japan's Ministry of Education, Culture, Sports, Science, and
Additional support comes from the European Consortium
for Ocean Research Drilling and the People's Republic of China,
Ministry of Science and Technology.
Canada is a member of the
When brought to the surface in a core, gas hydrate is no longer
its stable pressure and temperature field and decomposes (see
fizzing and bubbling).
(Image courtesy of Integrated Ocean Drilling
Program Management International)
An international team of scientists
supported by the Integrated Ocean Drilling Program (IODP) has
completed a unique research expedition aimed at recovering samples
of gas hydrate, an ice-like substance hidden beneath the seafloor
off Canada's western coast.
Gas hydrate, a mixture of water and
mostly methane, is believed to occur under the world's oceans in
great abundance, but it quickly "melts" once removed from the high
pressure and cold temperatures of its natural environment, making it
very challenging to recover and analyze.
"We're interested in gas hydrate because we believe these deposits
have played an important role in ancient global climate change,"
explains Michael Riedel of Natural Resources Canada's Geological
Survey of Canada, IODP Expedition 311's co-chief scientist.
expedition is the first to explore a transect of deep drilling
research sites across the Cascadia Continental Margin and will yield
new data that will help us understand the deep origin of the methane
that composes the gas hydrate, how the methane is transported into
the sediments where gas hydrate exists, and how methane is
eventually released into the ocean, and possibly, into the
atmosphere where it could impact climate."
"What we've found will fundamentally change how we investigate the
impact of gas hydrate deposits," confirms IODP co-chief scientist
Timothy S. Collett of the U.S. Geological Survey, Denver, Colo.
"Expedition 311 has shown that the occurrence of gas hydrate is much
more complex than predicted. Instead of finding gas hydrate
concentrated in one layer," he explains, "near the base of the zone
where it is stable, higher concentrations of gas hydrate were found
within coarse-grained sand layers throughout core samples from most
of the sites drilled."
Scientists and engineers aboard IODP's U.S.-sponsored research
drilling vessel, the
JOIDES Resolution, drilled hundreds of meters
below the seafloor and successfully retrieved gas hydrate in long
More than 1,200 meters of sediment core samples were
recovered from beneath the seafloor during this 37-day expedition.
Once core samples are brought onto the ship, marine laboratory
specialists work quickly to scan them using various sensors and
computers to find the gas hydrate, which is unstable at the surface.
Most previous research on the
Cascadia Continental Margin has
focused on conducting detailed, remote sensing studies to image gas
hydrate in the oceanic sediments. In past research efforts, gas
hydrate has been recovered from the Cascadia Margin area using
shallow sediment coring systems that allowed only the upper few
meters of sediment to be sampled.
Among the discoveries of Expedition 311 was a thick section of gas
hydrate lying near the seafloor surface beneath an active vent site,
known as the 'bull's-eye vent,' where methane gas naturally seeps
from the seafloor.
This vent site is one of many similar sites
observed along the Cascadia Margin and scientists are just starting
to understand their role in the overall history of the margin. The
episodic nature of the venting and the potential link to earthquake
activity, as well as the possible impact on gas release into the
ocean and atmosphere, will be researched for many years to come,
when future drill site observatories will be linked with the NEPTUNE
cable observatory system.
Scientists first became interested in gas
hydrate in 1982, when it was discovered during a research leg of the
Deep Sea Drilling Project, one of two U.S.-sponsored scientific
drilling programs that predate IODP.
The samples were retrieved from
the Middle American Trench region, off the Pacific coast of
Since then, gas hydrate has been the focus of numerous
'Frozen' Natural Gas
...Discovered At Unexpectedly Shallow Depths
August 22, 2006
An international team of research
scientists has reported greater knowledge of how gas hydrate
deposits form in nature, subsequent to a scientific ocean-drilling
expedition off Canada’s western coast.
A natural geologic hazard, gas hydrate
is largely natural gas, and thus, may significantly impact global
climate change. The research team, supported by the Integrated Ocean
Drilling Program (IODP),
published their peer-reviewed findings, "Gas
Hydrate Transect Across Northern Cascadia Margin," in the
Aug. 15, 2006, edition of EOS, published by the American Geophysical
Contrary to established expectations of how gas hydrate deposits
form, IODP expedition co-chief Michael Riedel, of McGill
University, Montreal, confirms,
“We found anomalous occurrences of
high concentrations of gas hydrate at relatively shallow depths,
50-120 meters below the seafloor.”
The science party used the drilling
facility and laboratories of the U.S. research vessel, JOIDES
Resolution, on a 43-day expedition in Fall 2005 during which they
retrieved core samples from a geological area known as the
(northern) Cascadia Margin.
Gas hydrate deposits are typically found
below the seafloor in offshore locations where water depths exceed
500 meters, and in Arctic permafrost regions. Gas hydrate remains
stable only under low temperature and relatively high pressure.
IODP co-chief scientist Timothy S. Collett of the U.S.
Geological Survey states,
“After repeatedly recovering high
concentrations of gas hydrate in sand-rich layers of sediment,
we’re reporting strong support for sediment grain size as a
controlling factor in gas hydrate formation.”
Prior to drilling, the scientists
anticipated that gas hydrate would be more concentrated at deeper
levels below the seafloor and more evenly distributed among the
various grain sizes comprising the sediments.
The Integrated Ocean Drilling Program (IODP) is an
international marine research program dedicated to advancing
scientific understanding of the Earth, the deep biosphere, climate
change, and Earth processes by sampling and monitoring sub-seafloor
IODP is supported by two lead agencies:
the U.S. National Science
Japan’s Ministry of Education,
Culture, Sports, Science, and Technology
Additional support comes from a European
consortium of 17 countries, the People’s Republic of China, and
U.S.-sponsored IODP drilling operations
are conducted by the JOI Alliance, comprised of,
the Joint Oceanographic
Texas A & M University Research
Lamont-Doherty Earth Observatory
of Columbia University