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 Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>