Figure 1. Carolyn Ruppel (Georgia
Tech) and Gerald Dickens (Rice) plan scientific operations at the
Bush Hill gas hydrate site aboard the R/V Seward Johnson.
Carolyn Ruppel’s hands precede her, shaping the words
that just won’t come quite quickly enough. They describe, they mold:
the right hand, a cage of solid gas hydrate, intended to represent
but one molecule of an untold global store – the left, a sound wave,
descending to encounter said hydrate. They’re giving form to a mystery,
the mystery of a life, way down deep in the ocean.
Ruppel is an Associate Professor of Geophysics in Georgia
Tech’s School of Earth and Atmospheric Sciences (Figure 1).
She’s at the forefront of interdisciplinary research into gas hydrates
that is engaging a growing number of scientists with divergent interests
Gas hydrates are crystalline lattices of gases and water
that remain frozen and stable at just the right balance of high pressure
and low temperature – conditions found, as we’re now learning, beneath
the seafloor all over the globe, generally at depths in excess of 500
meters, as well as in the Arctic permafrost (Figure 2).
Light a match to a gas hydrate, and it’ll burn like a candle. In many
locations, the primary gas in gas hydrates is methane.
Figure 2. A gas hydrate consists
of a gas molecule (green) trapped in a cage of water molecules (red).
Gas hydrates remain a great mystery, but less so every
day. Which is why in 2001 the National Oceanic and Atmospheric Administration’s
Undersea Research Program (NURP) funded Ruppel and a team of scientists
and students, headed by biologist Cyndy Van Dover, to learn more
about the Blake Ridge, an area off the coast of South Carolina,
where large deposits of gas hydrates are known to occur in the deep
What’s behind all this attention?
First, we must consider the economic driver: The methane
held within gas hydrates may have an astonishing, heretofore unrealized
potential as an energy source. It is estimated that the energy potential
within is well in excess of that of the Earth’s combined conventional
Second, they’re known to be associated with seafloor stability,
a matter of increasing interest to oil companies as they drill ever deeper
into the oceans. Drilling through hydrates can cause the gas and water
within to separate, potentially destabilizing the sediment on the ocean
Third, the release of methane during meltdown of hydrates
is believed to contribute to global warming.
Figure 3. Gas hydrates are inhabited
by unique chemosynthetic ecosystems, where organisms create energy
through chemical reactions. Pictured here is a spider crab in a
bed of mussels. © NURP and Texas A&M.
And, finally, knowledge gained through gas hydrate research
is informing the study of the deep biosphere, a largely unexplored frontier
in which life forms sustained by means other than photosynthesis have
been discovered – discoveries for which we may find numerous practical
applications (e.g. bio-products).
The unfolding of the mystery of gas hydrates and of the
world in which they live – and the examination of how they might help
us humans meet our energy needs – is also an excellent example of interdisciplinary
science at work to mutual and manifest benefit.
“There’s been a real convergence of interest [in gas hydrates],”
says Ruppel. “We’re all trying to get educated in other, related fields,
because to make fundamental breakthroughs in science now, we’re going
to have to think in a more integrative way; we’re going to have to rely
on people who are not in our area of expertise.”
Andrew Shepard understands full well the importance of an
interdisciplinary approach to a venture as complexly textured as the understanding
of gas hydrates. Shepard is Associate Director of the National
Undersea Research Center at the University of North Carolina at Wilmington,
one of six NURP Centers across the U.S., which supports undersea research
off the southeastern coast of the U.S. and in the Gulf of Mexico. Interdisciplinary
effort, he says, “is really the only way you should do these kinds of
expeditions. Due to the time and resources required, the opportunities
you get are very rare.”
NURP has been actively involved in gas hydrate research
for nearly a decade. NURP realized long ago that hydrates and the deep-sea
biosphere hold tremendous potential for advancing scientific knowledge
and useful applications. Among the uses of extremophiles – organisms that
thrive in extreme environments without light – recovered from land and
sea are bio-products that have been used for cancer detection, DNA amplification
in criminal cases, and proteases and lipases for dairy products (Figure
How much gas hydrate is out there? No one knows for certain.
But Bilal Haq of the Division of Ocean Sciences at the National Science
Foundation, wrote in 1999: “Even relatively conservative estimates indicate
that on the order of 10,000 gigatons of carbon, or double the amount of
all known fossil fuel sources, may be stored in gas hydrates.”
On May 2, 2000, Bill Clinton signed the Methane
Hydrate Research and Development Act, authorizing a $47.5
million, five-year program for research of gas hydrates. Interest
continues to rise; uncertainties are many.
“The reasons hydrate can be difficult to view as an energy
resource,” says Ruppel, “are primarily related to the technological advances
we’re going to need. There is a demonstration project that’s aimed at
producing methane from gas hydrate as an alternative energy resource.
Some of the technological problems include difficulty extracting the resource
and, even more fundamentally, locating the resource.
“It’s going to require an investment of intellect and energy
and time to really move from what we know in the lab or on the basis of
computer models to understanding the so-called ‘dirty system’” – in other
words, in the real world, which is complicated and heterogeneous and very
unlike a lab, which can be arranged just so.
“My guess,” says Patricia Sobecky, an Assistant Professor
of Microbiology at Georgia Tech whose work is very much interrelated to
Ruppel’s, “is that once you know what the microbes are doing, once you
know the activity, once you know the rate, then you can answer the question
of whether they’re renewable and on what kind of time scale we’re talking
– days, months, years, decades?”
Which is precisely what Carolyn Ruppel’s hands are doing
at this moment: molding the broader perspective. It’s exciting work.
Additional information about Carolyn Ruppel's research on
gas hydrates can be found at: