Researchers Dig Deep Into Wyoming Basin for Global Warming Clues
About 55 million years ago, the Earth burped up a massive release of
carbon dioxide into the atmosphere – an amount equivalent to burning
all the petroleum and other fossil fuels that exist today. “And we
don’t know where it came from,” says University of New Hampshire’s Will
Clyde, associate professor of geology. “This is a big part of the
carbon cycle that affected the climate system, and we don’t understand
it.”
This month, Clyde is leading a pioneering National Science
Foundation-funded geological study in the Bighorn Basin of Wyoming to
search for clues to this event, which occurred during a period of
extreme warming called the Paleocene-Eocene Thermal Maximum (PETM). A
team of 27 scientists from 11 institutions will drill a series of cores
into the basin’s stratified layers of rocks that they hope will yield
better understanding of this mystery and – perhaps – of current and
future global climate change.
This field work, in an area just
east of Yellowstone National Park near Cody, Wyo., will be the first
time scientists have drilled continental cores in an attempt to better
understand this release of carbon and the warming, an environmental
anomaly called a hyperthermal event, that surrounded it. Previous
research has utilized ocean cores or more weathered rock outcroppings.
The
sedimentary deposits in the semi-arid, 100-mile-wide Bighorn Basin
created ideal conditions for studying the PETM. Drilling
two-and-a-half-inch diameter cores about 150 meters into the sediment,
says Clyde, will advance research by providing pristine sediments on
which scientists can do more precise geocehmical analyses.
“It
will help us better understand the long-term carbon cycle of the
Earth,” says Clyde, who chairs the Earth sciences department in UNH’s
College of Engineering and Physical Sciences (CEPS).
It’s not
just ancient history Clyde and his colleagues are interested in.
Researchers suspect that the carbon release may have been a result of
an initial rise in temperature during the PETM and they wonder whether
current warming, due to global climate change, could launch a similar
event. Further, the PETM provides insights into the carbon cycle,
climate system, and how living organisms respond to environmental
change.
“Could our dependence on carbon-based energy sources
trigger one or more causes of prehistoric global warming and, as a
result, make our struggle with a warming earth far worse than currently
predicted? ” asks Clyde.
Between July 13 and Aug. 11, 2011, the
scientists will drill pairs of cores at three sites – Polecat Bench,
Gilmore Hill, and Basin Substation – around the Bighorn Basin. In
partnership with a professional drilling team, scientists will work
around the clock for a week at each site; each core, says Clyde, could
take three days to drill.
“The nature of these rocks makes them
particularly hard to core,” he says, adding that because this type of
scientific drilling has never been conducted on these kinds of
deposits, the team will be pioneering some of this work.
Once
collected, the cores will be shipped in refrigerated containers to the
University of Bremen in Germany. Clyde and the team will visit that
laboratory in January 2012 to continue studying the cores, measuring
the isotopic signature of carbon residue in the rocks to determine the
amount of carbon released into the atmosphere during hyperthermals.
Clyde
is optimistic about the project’s ability to shed light on previous and
potential global warming. “Hopefully, by looking at the past, we will
better understand prospects for the long-term climate cycle that may or
may not become our future.”
This
research was funded by a $1.4 million grant from the National Science
Foundation. In addition to Clyde, master’s students Abby D'Ambrosia and
Jeremy Riedel and project manager Doug Schnurrenberger from UNH, and
scientists from the following instutitions will participate:
Universities of Michigan, Colorado, Wyoming, Birmingham (U.K.), and
Bremen (Germany); Columbia, Northwestern, Pennsylvania State, Purdue,
and Utrecht (Netherlands) universities; the Smithsonian Institution;
Bureau of Land Management; Denver Museum of Nature and Science;
ExxonMobil; LacCore; NIOZ (Royal Netherlands Institute for Sea
Research); and South Dakota School of Mines & Technology.