What caused the end of a warm climate phase and an expansion of the Antarctic ice sheet 14 million years ago? This is the question addressed by Kiel and Bremen palaeoclimatologists in an article for the latest issue of Nature (24/11/05). Their research uncovered a temporal link between a reduction in carbon dioxide (CO²) levels on earth, ice sheet formation and global cooling. The "global cooling" that took place 14 million years ago is attributed by Dr. Ann Holbourn, Professor Wolfgang Kuhnt, Professor Michael Schulz and Dr. Helmut Erlenkeuser to changes in the marine carbon cycle, associated with variations in Earth’s orbit and tilt.
Kuhnt: "We know that the orbital situation, i.e. the path followed by the Earth around the Sun, changes regularly. One such change occurred during the global cooling period 14 million years ago, bringing with it a period of cool Antarctic summers. The Antarctic ice sheet was no longer melting down in summer and began to grow steadily. For the first time we can reconstruct in great detail the history of this glacial expansion, which took place in about 80,000 years, a short time in geological terms.”
Researchers at the Institute for Geosciences of the Christian-Albrechts-Universität in Kiel and their colleague from DFG Research Center Ocean Margins in Bremen studied marine sediments from two cores in the eastern and western subtropical Pacific. The analysis of oxygen and carbon isotopes in the calcite shells of tiny organisms (foraminifers) living at the sea floor allowed to track changes in ice volume and carbon dioxide levels. The team investigated an interval of about two million years with a sampling resolution of 4,000 years.
Susanne Schuck | alfa
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The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
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In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
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