International Greenland ice coring effort sets new drilling record in 2009August 27, 2009A 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." University of Colorado at Boulder |
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| Related Ice Cores Current Events and Ice Cores News Articles Research challenges for understanding landscape changes identified Nine research challenges and four research initiatives that are poised to advance the study of how Earth's landscapes change were unveiled today in a new report by the National Research Council. Arctic lake sediments show warming, unique ecological changes in recent decades An analysis of sediment cores indicates that biological and chemical changes occurring at a remote Arctic lake are unprecedented over the past 200,000 years and likely are the result of human-caused climate change, according to a new study led by the University of Colorado at Boulder. As Greenland melts Not that long ago - the blink of a geologic eye - global temperatures were so warm that ice on Greenland could have been hard to come by. Today, the largest island in the world is covered with ice 1.6 miles thick. Even so, Greenland has become a hot spot for climate scientists. Cosmic Rays Hit Space Age High Planning a trip to Mars? Take plenty of shielding. According to sensors on NASA's ACE (Advanced Composition Explorer) spacecraft, galactic cosmic rays have just hit a Space Age high. The least sea ice in 800 years New research, which reconstructs the extent of ice in the sea between Greenland and Svalbard from the 13th century to the present indicates that there has never been so little sea ice as there is now. The research results from the Niels Bohr Institute, among others, are published in the scientific journal, Climate Dynamics. Close relationship between past warming and sea-level rise In a paper in Nature Geoscience, a team from the National Oceanography Centre, Southampton (NOCS), along with colleagues from Tübingen (Germany) and Bristol presents a novel continuous reconstruction of sea level fluctuations over the last 520 thousand years. Ancient drought and rapid cooling drastically altered climate Two abrupt and drastic climate events, 700 years apart and more than 45 centuries ago, are teasing scientists who are now trying to use ancient records to predict future world climate. Global monsoon drives long-term carbon cycles in the ocean Monsoon is a global system, and many arrays of evidence indicate that it drives long-term cyclicity of the carbon reservoir in the global ocean. Dust may settle unanswered questions on Antarctica Dust trapped deep in Antarctic ice sheets is helping scientists unravel details of past climate change. Satellites confirm half-century of West Antarctic warming The Antarctic Peninsula juts into the Southern Ocean, reaching farther north than any other part of the continent. The southernmost reach of global warming was believed to be limited to this narrow strip of land, while the rest of the continent was presumed to be cooling or stable. More Ice Cores Current Events and Ice Cores News Articles |
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