Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Pittsburgh Geologists Map Prehistoric Climate Changes in Canada’s Yukon Territory

09.05.2012
Pitt study one of many across the nation focused on understanding Arctic region’s climate changes

Researchers at the University of Pittsburgh have joined an international group of scientists to study past climate changes in the Arctic.

Comprising geologists from Pitt’s Department of Geology and Planetary Science, the team has analyzed sedimentary and geochemical records of water-level changes in Rantin Lake, located in the boreal forest of Canada’s southeastern Yukon Territory.

The results were published online in the April issue of Journal of Paleolimnology as one of 18 articles dedicated to reconstructing Arctic lake sediments climate and environmental changes during the Holocene (about 12,000 years before present day).

“During the last 10,000 years, there have been certain times in which rapid climate change events occurred,” said David Pompeani, lead author and a Pitt PhD geology student. “By analyzing Rantin Lake, we’ve contributed a piece of the puzzle toward mapping the timing and magnitude of these prehistoric events throughout the Arctic.”

Rantin Lake is part of a watershed containing a series of small lakes hydrologically connected through groundwater flow. The regional climate is subarctic and characterized by warm, wet summers and dry, cold winters. The lake is located at 60 degrees north in the Canadian Arctic, only 30 degrees away from the North Pole, where climate change is expected to be amplified.

In July 2006, the Pitt team—including Mark Abbott, associate professor of geology and planetary science, and Byron Steinman, a former PhD geology student (now a postdoctoral researcher at Penn State University)—collected two sediment cores from the lake for analysis. The sediment cores were split and analyzed for paleoclimate proxy indicators, including geochemical composition, sedimentary structure, and macrofossil content (that which is visible without a microscope). The amount of water in a lake is directly related to its depth. Therefore, a loss in water during droughts is recorded by drop in lake levels, whereas wet periods are characterized by deep waters.

Using these proxy indicators, the researchers were able to make inferences about past variations in the balance between precipitation and evaporation in the southern Yukon. A comparison of the lake-level proxies with a previously developed fossil pollen record from the same lake found that rapid vegetation changes over the Holocene also occurred during shifts in the precipitation/evaporation balance, suggesting hydrologic conditions played an integral role in the evolution of the Yukon’s ecosystem. The development of unique shallow-water sediment at the deep-water core site indicated that lake levels dropped significantly during a “megadrought” in the early Holocene.

“About 8,400 years ago, the lake almost dried out,” said Pompeani. “We documented the timing of this drought and studied its transition to conditions more typical of what we observed in the late Holocene.”

Pitt’s study, says Pompeani, contributes to the long-term perspective on natural climate variability that is needed to understand historically unprecedented changes now occurring in the Arctic. Rapid changes in the Arctic climate system that occurred in the relatively recent past can be compared with climate models to improve the understanding of the processes responsible for such nonlinear changes.

Funding for this project was provided by the National Science Foundation.

The Holocene climate project focuses on climate records from the last 8,000 years, including two focus regions: eastern Beringia and the northwest Atlantic. For more information on the Holocene climate project, visit www.arcus.org/synthesis8k/index.php

B. Rose Huber | EurekAlert!
Further information:
http://www.pitt.edu

More articles from Earth Sciences:

nachricht Do ice cores help to unravel the clouds of climate history?
21.06.2019 | Leibniz Institute for Tropospheric Research (TROPOS)

nachricht News from the diamond nursery
21.06.2019 | Goethe-Universität Frankfurt am Main

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer IDMT demonstrates its method for acoustic quality inspection at »Sensor+Test 2019« in Nürnberg

From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.

Reducing machine downtime, manufacturing defects, and excessive scrap

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

'Sneezing' plants contribute to disease proliferation

24.06.2019 | Agricultural and Forestry Science

Researchers find new mutation in the leptin gene

24.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>