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| 2006 June 1 |
Ocean-Drilling Scientists Cite History of Arctic
Climate Change
Key Findings Published in Nature |
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Swedish drilling vessel, Vidar Viking, led
the Arctic Coring Expedition in Aug. and Sept. 2004, when scientists set
out
to retrieve subseafloor sediment records to support their investigations
into climate change.
Photo: IODP/ESO |
A group of ocean-drilling research scientists that explored
the Arctic Ocean subseafloor in Fall 2004 have released new findings in a
report to be published in Nature on June 1. The report, supported by Integrated
Ocean Drilling Program (IODP) research operations, contains analyses of subseafloor
sediment samples gathered from 430 meters beneath the Arctic Ocean, near
the North Pole. To recover the sediments that yielded the prehistoric climate
records, the research team needed to manage three ice-breakers, one of which
was equipped with a drill rig. The sediment records were recovered from the
Lomonsov Ridge, in water about 1000 meters deep.
The IODP Arctic Coring Expedition (ACEX) scientists report their key findings
in Nature:
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Evidence of ice in the Arctic Ocean was found much earlier than formerly
believed, about 45 million years ago |
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At one time about 55 million years ago, Arctic temperatures rose to
subtropical levels (about 23 degrees Centigrade) |
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At one time about 49 million years ago, the Arctic was green, with
fresh surface water and large amounts of fern covering the water, at
least in summer months. |
Expedition co-chief scientist Kathryn Moran, University of Rhode Island, notes
that the overall age span of the sediments recovered was a few million years
longer than was expected to retrieve. Such successful recovery was possible,
in large part, due to strategic planning in anticipation of strenuous ice management.
Planners had predicted that the three-vessel fleet could maintain the drilling
vessel’s station for up to two full days, yet the station-keeping achievements
went far beyond this expectation. The Vidar Viking was kept on location in
multi-year ice for nine days - a landmark feat that empowered ACEX scientists
to sustain their ocean-drilling explorations for a significant period. “The
scientific community benefited from our extraordinary ice management efforts
- we are the first to study full geologic records from the Arctic Ocean,” said
Moran.
Moran’s colleague, co-chief scientist Jan Blackman, a professor at Stockholm
University, Sweden, also recalls the challenging research conditions. “At
times, the drill site was covered with ice two to three-meters thick. We encountered
an ice flow of multi-year ice, harder and denser than ice from just one Arctic
winter; it was like driving into a brick wall.” The upper sections (160
meters) of retrieved sediments indicate prevailing ice conditions during the
last 14-16 million years.
A summary of the Arctic Coring Expedition, IODP Proceedings, Volume 302, is
available online. The volume includes scientific and engineering results, drilling
location maps, visual core descriptions and core photographs.
Visit http://www.ecord.org/exp/acex/vol302/.
Additional photos, excerpts from the original expedition logbook, a full list
of science party members, and other details can be found on the expedition
web page,
http://www.ecord.org/exp/acex/302.html.
IODP Expedition 302 was conducted by the European Consortium for Ocean Research
Drilling (ECORD), through the ECORD Science Operator (ESO), one of three regional
IODP drilling operators, and the program’s specialist in mission-specific
platform operations. ECORD represents 17 nations and operates in IODP as a
contributing member.
IODP promotes scientific advancement of the Earth through monitoring and sampling
of subseafloor environments. An international program that supports scientists
from 20 countries, IODP receives its primary funding from the U.S. and Japan,
through the National Science Foundation and the Ministry of Science, Education,
Culture, Sports, Science and Technology, respectively. For more program information,
visit www.iodp.org.
*ACEX Expedition Scientists from JAPAN
Kozo Takahashi (Department of Earth and Planetary Sciences, Kyushu Univ.)
Jonaotaro Onodera (Department of Earth and Planetary Sciences, Kyushu Univ.)
Itsuki Suto (Department of Earth & Planetary Sciences, Nagoya Univ.)
Tatsuhiko Sakamoto (Institute for Research on Earth Evolution (IFREE), JAMSTEC)
Noritoshi Suzuki (Institute of Geology & Paleontology, Tohoku Univ.)
Masanobu Yamamoto (Graduate School of Environmental Earth Science, Hokkaido
Univ.)
Richard W. Jordan (Department of Earth & Environmental Sciences, Yamagata
Univ.)
Mahito Watanabe (Institute of Geoscience, Geological Survey of Japan, AIST)
Contacts:
Nancy Light, IODP Management International: +1-202-361-3325, nlight@iodp.org
Cheryl Dybas, National Science Foundation: +1-292-7734, cdybas@nsf.gov
Alan Stevenson, ECORD/ESO: +44-131-650-0376, agst@bgs.ac.uk
Albert Gerdes, ECORD/ESO: +49-421-218-65540, agerdes@marum.de
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