Sensational climate research in the Arctic: longest climate archive of the terrestrial Arctic retrieved
Bremerhaven/Cologne June 2nd 2009. An international team of researchers from Russia, Germany, the USA and Austria has conducted a deep drilling program in the far northeast of Russia during the last six months to retrieve several hundred meters of lake sediments, impact breccias and permanently frozen soil. These make new insights into the climate history of the Arctic, crater formation of Lake El’gygytgyn and permafrost dynamics possible. A milestone has been reached at the beginning of May with the first results of the drilling campaign. The cores gained will help to answer crucial open questions of Arctic geology.
At the far northern fringe of north-eastern Siberia, about 900 km west of the Bering Strait and 100 km north of the Arctic Circle (67°30’ N, 172°05’ E), lies Lake El’gygytgyn which originated 3.6 Mio years ago from a meteorite impact. The lake has, in contrast to other areas of this latitude, never been glaciated - the sediments which accumulated continually at the bottom of the lake are therefore an invaluable Arctic climate archive.
International researchers from various disciplines have set the goal to retrieve this archive. Preparations took eleven years before the large scale deep drilling campaign began at the end of the last year. Infrastructure for up to 40 people had to be created in this remote area under the most difficult conditions - accommodations, sanitary installations and supply utilities.
“Humans and technical appliances need sufficient energy in temperatures of down to -45°C, for instance for storing the drilling cores above freezing point”, says Martin Melles from the University of Cologne, project manager of the El’gygytgyn Drilling Project on the side of the Germans. The drilling equipment employed for drillings in the lake weighs about 70 tons, a great challenge for its safe positioning on the lake ice.
At the end of the last year, permafrost drillings were performed by a Russian construction company from the 260 km distant Pevek. It yielded impressive results: the team reached a drilling depth of 142 metres despite heavy snowstorms and low temperatures. The cores contain information on the permafrost history and its influence on lake sedimentation. “It is possible to read lake level fluctuations from the cores”, reports Georg Schwamborn from the Research Station Potsdam of the Alfred Wegener Institute who headed the permafrost drillings. Of great importance is the installation of a temperature measurement chain in the drilling hole by the researchers from Potsdam. It documents the current changes in the permafrost soil. Its understanding is of great value for climate research since the release of the gases bound in the thawing permafrost might further reinforce the greenhouse effect.
The lake drillings which have just been completed were no less successful: lake sediments were drilled 315 meters below the lake bottom; the upper 110 meters overlapped to close the remaining gap of the first drilling in the archive. First results indicate that the climate and environment history of the last 3.6 Mio years is largely documented. Measurements of the magnetic properties in the upper part of the sediment layers show numerous warm and glacial periods with different intensities and characteristics. “We can learn from detailed examinations of the transition from a glacial to a warm period that the Arctic reacted to global warming in the past; it is therefore safe to assume that it will also react to it in the future “, explains Catalina Gebhardt from the Alfred Wegener Institute in Bremerhaven. The deepest lake sediment cores reached into the Pliocene of 2.6 Mio years ago. “These sediments are of unique importance because the climate of this time was considerably warmer than it is today”, says Martin Melles. “The insights gained from these sediments can serve as a perfect example for the Arctic in a few years time, in case the global warming takes place as prognosticated by climate models.”
An important goal of the lake drilling was the drilling of the impact breccias. This clastic rock created by a meteorite impact was found 315 meters below the lake bottom. The cores drawn by drilling 200 meters into the breccias are invaluable. “We expect new insights not only about the trajectory and composition of the meteorite, but particularly about the reactions of the volcanic rocks to the impact”, says Christian Koeberl from the University of Vienna, who coordinates the international team processing the impact rocks. The insights serve the risk assessments in areas with similar rock formations.
The 3.5 tons of cores drilled in 2009 will be brought to the Russian Arctic and Antarctic Research Institute (AARI) in St. Petersburg at the start of June. The cores of the whole drilling campaign will thereafter be brought to Germany: the permafrost cores to the Alfred Wegener Institute for Polar and Marine Research, the lake sediments to the University of Cologne and the impact breccias to the ICDP in Potsdam. The examinations will take two years. Altogether, about 30 guest researchers next to the German researchers and students will work on the cores.
You can find information of the project here: http://www.elgygytgyn.uni-koeln.de
Partner research institutes:
Russian: NEISRI Magadan and AARI St. Petersburg
German: Alfred Wegener Institute for Polar and Marine Research, German Research Centre for Geosciences Potsdam and the University of Cologne
American: University of Massachusetts
Austrian: University of Vienna
Heads of the project:
Russian: Pavel Minyuk, NEISRI Magadan
German: Martin Melles, University of Cologne (he also coordinates the German partners and their subprojects)
American: Julie Brigham-Grette, University of Massachusetts
Austrian: Christian Köberl, University of Vienna
The El’gygytgyn Drilling Project is funded by the ICDP, BMBF, NSF, RAS, the BMWF and the Helmholtz Centres Alfred Wegener Institute and the German Research Centre for Geosciences.
Notes for Editors:
Your contact persons at the Alfred Wegener Institute are Dr. Catalina Gebhardt (phone: 0471 4831-1946; email: Catalina.Gebhardt@awi.de) and Dr. Georg Schwamborn (phone: 0331 288-2174; email: Georg.Schwamborn@awi.de). Your contact person in the public relations department is Magdalena Hamm (phone: 0471 4831-2008; email: Magdalena.Hamm@awi.de).
The Alfred Wegener Institute carries out research in the Arctic and Antarctic as well as in the high and mid latitude oceans. The institute coordinates German polar research and provides international science with important infrastructure, e.g. the research icebreaker Polarstern and research stations in the Arctic and Antarctic. The Alfred Wegener Institute is one of 15 research centres within the Helmholtz Association, Germany’s largest scientific organization.
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The Alfred Wegener Institute pursues research in the polar regions and the oceans of mid and high latitudes. As one of the 19 centres of the Helmholtz Association it coordinates polar research in Germany and provides ships like the research icebreaker Polarstern and stations for the international scientific community.