Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How Antarctica turned white

29.01.2013
Weathering of Antarctic rocks lowers atmospheric carbon dioxide concentration during the Eocene-Oligocene transition

Thirty four million years ago, Antarctica was covered with temperate forests that included beech trees and cycads. Then, over a geologically short period of 200,000 years, global temperatures cooled and Antarctica became the frozen continent it is today. These pervasive climatic changes may be linked to weathering processes on the Antarctic continent.


Typical deep ocean sediment cores. Scientists use geochemical signals hidden in these sediments to reconstruct Earth’s climate history.
Katharina Pahnke

Dr. Chandranath Basak of the Max Planck Research Group Marine Isotope Geochemistry located at the University of Oldenburg, and his co-author Dr. Ellen Martin from the University of Florida found out that weathering of different types of rocks contributed towards the observed climate change at the Eocene/Oligocene boundary.

For this study they used deep-sea sediments obtained from the Integrated Ocean Drilling Program, a large-scale programme for scientific ocean drilling. In their publication in the scientific journal Nature Geoscience they suggest that weathering processes on the Antarctic continent may have been instrumental in lowering the carbon dioxide concentrations in the atmosphere, causing the observed climate cooling and subsequent ice growth.

When rocks are subjected to weathering, they can change the chemistry of the ocean, and the remnants sooner or later end up at the bottom of the ocean. Scientists can “read” such events in Earth’s history from these sediments, deposited over millions of years. They use characteristics in the composition of the sediment by which they can reconstruct processes in the past. Dr. Basak and Dr. Martin have analysed lead (Pb) isotopes in sediment samples and used a new approach to study weathering of the continents in the past.

“This method allows us to differentiate between chemical weathering, meaning alteration by chemical processes, and physical weathering, for example breakdown by glaciers”, says Dr. Basak. They could find evidence of carbonate rock weathering on Antarctica during ice growth, which may have contributed to chemical changes in the ocean that led to enhanced carbonate deposition, which is referred to as an ocean de-acidification event in contrast to modern ocean acidification.

Chandranath Basak says: “It is not easy to reconstruct the processes associated with climate change that occurred millions of years ago during the Eocene-Oligocene transition. Yet with our work we believe we could improve our understanding of this transitional period.”

For further information please contact:
Dr. Chandranath Basak, cbasak@mpi-bremen.de Telephone: 0441 798 3359
Or the press office:
Dr. Rita Dunker rdunker@mpi-bremen.de Telephone 0421 2028 856
Dr. Manfred Schlösser mschloes@mpi-bremen.de Telephone 0421 2028 704
Involved Institutions:
Max Planck Institute for Marine Microbiology
Max Planck Research Group for Marine Isotope Geochemistry, Instutite for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany

University of Florida, Department of Geological Sciences, Gainsville, USA

Original Publication:
Basak, C. and Martin, E.E. (2013). Antarctic weathering and carbonate compensation at the Eocene-Oligocene transition. Nature Geosciences, advanced online Publication.

Doi: 10.1038/NGEO1707

Dr. Manfred Schloesser | Max-Planck-Institut
Further information:
http://www.mpi-bremen.de

More articles from Earth Sciences:

nachricht NASA examines Peru's deadly rainfall
24.03.2017 | NASA/Goddard Space Flight Center

nachricht Steep rise of the Bernese Alps
24.03.2017 | Universität Bern

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

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...

Im Focus: Tracing down linear ubiquitination

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.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>