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.
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.”
University of Florida, Department of Geological Sciences, Gainsville, USAOriginal Publication:
Dr. Manfred Schloesser | Max-Planck-Institut
Geophysicists and atmospheric scientists partner to track typhoons' seismic footprints
16.02.2018 | Princeton University
NASA finds strongest storms in weakening Tropical Cyclone Sanba
15.02.2018 | NASA/Goddard Space Flight Center
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
19.02.2018 | Materials Sciences
19.02.2018 | Materials Sciences
19.02.2018 | Life Sciences