A new international research effort on the Greenland ice sheet with the University of Colorado at Boulder as the lead U.S. institution set a record for single-season deep ice-core drilling this summer, recovering more than a mile of ice core that is expected to help scientists better assess the risks of abrupt climate change in the future.
The project, known as the North Greenland Eemian Ice Drilling, or NEEM, is being undertaken by 14 nations and is led by the University of Copenhagen. The goal is to retrieve ice from the last interglacial episode known as the Eemian Period that ended about 120,000 years ago. The period was warmer than today, with less ice in Greenland and 15-foot higher sea levels than present -- conditions similar to those Earth faces as it warms in the coming century and beyond, said CU-Boulder Professor Jim White, who is leading the U.S. research contingent.
While three previous Greenland ice cores drilled in the past 20 years covered the last ice age and the period of warming to the present, the deeper ice layers representing the warm Eemian and the period of transition to the ice age were compressed and folded, making them difficult to interpret, said White. Radar measurements taken through the ice sheet from above the NEEM site indicate the Eemian ice layers below are thicker, more intact and likely contain more accurate, specific information, he said.
"Every time we drill a new ice core, we learn a lot more about how Earth's climate functions," said White, "The Eemian period is the best analog we have for future warming on Earth."
Annual ice layers formed over millennia in Greenland by compressed snow reveal information on past temperatures and precipitation levels and the contents of ancient atmospheres, said White, who directs CU-Boulder's Institute of Arctic and Alpine Research. Ice cores exhumed during previous drilling efforts revealed abrupt temperature spikes of more than 20 degrees Fahrenheit in just 50 years in the Northern Hemisphere.
The NEEM team reached a depth of 5,767 feet in early August, where ice layers date to 38,500 years ago during a cold glacial period preceding the present interglacial, or warm period. The team hopes to hit bedrock at 8,350 feet at the end of next summer, reaching ice deposited during the warm Eemian period that lasted from roughly 130,000 to 120,000 years ago before the planet began to cool and ice up once again.
The NEEM project began in 2008 with the construction of a state-of-the-art facility, including a large dome, the drilling rig for extracting 3-inch-diameter ice cores, drilling trenches, laboratories and living quarters. The official drilling started in June of this year. The United States is leading the laboratory analysis of atmospheric gases trapped in bubbles within the NEEM ice cores, including greenhouse gases like carbon dioxide and methane, said White.
The NEEM project is led by the University of Copenhagen's Centre of Ice and Climate directed by Professor Dorthe Dahl-Jensen. The United States and Denmark are the two leading partners in the project. The U.S. effort is funded by the National Science Foundation's Office of Polar Programs.
"Evidence from ancient ice cores tell us that when greenhouse gases increase in the atmosphere, the climate warms," said White. "And when the climate warms, ice sheets melt and sea levels rise. If we see comparable rises in sea level in the future like we have seen in the ice-core record, we can pretty much say good-bye to American coastal cities like Miami, Houston, Norfolk, New Orleans and Oakland."
Increased warming on Earth also has a host of other potentially deleterious effects, including changes in ecosystems, wildlife extinctions, the growing spread of disease, potentially catastrophic heat waves and increases in severe weather events, according to scientists.
While ice cores pinpoint abrupt climate change events as Earth has passed in and out of glacial periods, the warming trend during the present interglacial period is caused primarily by human activities like fossil fuel burning, White said. "What makes this warming trend fundamentally different from past warming events is that this one is driven by human activity and involves human responsibility, morals and ethics."
Other nations involved in the project include the United States, Belgium, Canada, China, France, Germany, Iceland, Japan, Korea, the Netherlands, Sweden, Switzerland and the United Kingdom.
Other CU-Boulder participants in the NEEM effort include INSTAAR postdoctoral researcher Vasilii Petrenko and Environmental Studies Program doctoral student Tyler Jones. Other U.S. institutions collaborating in the international NEEM effort include Oregon State University, Penn State, the University of California, San Diego and Dartmouth College.
For more information on the NEEM project, including images and video, visit http://www.neem.ku.dk.
Jim White | EurekAlert!
Is the Baltic Sea acidifying?
19.09.2018 | Leibniz-Institut für Ostseeforschung Warnemünde
Searching for clues on extreme climate change
18.09.2018 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.
Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
19.09.2018 | Life Sciences
19.09.2018 | Physics and Astronomy
19.09.2018 | Information Technology