A team of scientists from the United States, Germany, Russia and Austria returned recently from a six-month sediment drilling expedition at a frozen lake in Siberia, where they retrieved cores going back further than ever before collected in the Arctic—information they call “of absolutely unprecedented significance.”
Data will help scientists to understand the region’s geologic climate record. Cores collected from three holes under Siberia’s Lake El’gygytgyn, “Lake E” for short, are more than 30 times longer (in time) than records from the Greenland Ice Sheet, according to geoscientist Julie Brigham-Grette of the University of Massachusetts Amherst, the lead U.S. scientist. The lake was formed 3.6 million years ago when a meteor more than a half-mile in diameter hit the Earth and gouged out the 11-mile wide crater.
Lake E’s cores represent the longest time-continuous sediment record of past climate change in the terrestrial Arctic. The research team will compare this information with oceanic and land-based records from lower latitudes to better understand hemispheric global climate change and polar amplification.
In early June, the 3.5 tons of frozen sediment cores are being flown by special cargo plane from Siberia to St. Petersburg, then on to a lab at Germany’s University of Cologne for years of analysis by paleoclimatologists. Archive halves will arrive later at the University of Minnesota’s LacCore facility where they’ll be preserved in cold storage for future study.
Brigham-Grette says the team recovered a total of 1165 feet of sediment with replicate cores to roughly 2 million years ago with as high as 98 percent recovery. Studying high-latitude climate systems and how they react to changes in the global climate system is of great importance to climate research, she points out. Of prime interest is determining why and how the Arctic climate system evolved from a warm forested ecosystem into a cold permafrost ecosystem between 2 million and 3 million years ago.
“The continuous depositional record collected in this unique lake offers us a way to capture the dynamics and style of glacial/interglacial climate change when it was different in the past and why it was different,” Brigham-Grette explains. “Earth’s warm and cold cycles over the past 1 million years sometimes varied every 100,000 years but before that, climate change, especially in the high latitudes, varied over 41,000- and 23,000-year cycles, even before Northern Hemisphere glaciations got started 2.6 million years ago. The record from Lake E will show the ramp up to that type of change in the Earth’s climate.”
Below these sediments, cores drilled into bedrock at the site will offer geologists a rare opportunity to study impact melt rocks and target rocks from one of the best preserved large meteor impact craters on Earth, the only one formed in silicon-rich volcanic rock.
In addition, they collected sediment cores to the time of the meteor impact at 3.6 million years ago to 1033 feet below the lake floor. The lower material recovery there was due to “surprising sequences of coarse sand and gravel” interlaced with lake mud, Brigham-Grette notes. But these provide new revelations and suggest “unexpected glacial sources for these materials.” Overall, impact breccia cores will be sampled at a separate lab, the International Continental Drilling Program headquarters in Potsdam, Germany.
The team recovered roughly 131 feet of the earliest history of the lake in the warm middle Pliocene. This interval is fascinating, says Brigham-Grette, as a possible analog for future climate due to carbon dioxide forcing that can cause the greenhouse effect. However, initial results from the drilling are limited because sediment cores couldn’t be opened in the field at such a remote site.
The international Lake El’gygytgyn Drilling Project was funded by the International Continental Drilling Program (ICDP), the U.S. National Science Foundation’s Earth Sciences Division and Office of Polar Programs, the German Federal Ministry for Education and Research (BMBF), Alfred Wegener Institute (AWI), GeoForschungsZentrum-Potsdam (GFZ), the Russian Academy of Sciences Far East Branch (RAS/FEB), Russian Foundation for Basic Research (RFBR), and the Austrian Ministry for Science and Research.The leading Russian institutions include the Northeastern Interdisciplinary Scientific Research Institute (NEISRI), the Far East Geological Institute (FEGI), and Roshydromet’s Arctic and Antarctic Research Institute (AARI). The deep drilling system for Arctic operations was developed by DOSECC Inc. of Salt Lake City.
Findings from Lake E will become integrated into a network of sites collected by the geological community from the Arctic Ocean (ACEX) to Antarctica (especially ANDRILL).Julie Brigham-Grette
Julie Brigham-Grette | Newswise Science News
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences