Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

From greenhouse to icehouse -- reconstructing the environment of the Voring Plateau

16.12.2009
The environment of the Voring Plateau

The analysis of microfossils found in ocean sediment cores is illuminating the environmental conditions that prevailed at high latitudes during a critical period of Earth history.

Around 55 million years ago at the beginning of the Eocene epoch, the Earth's poles are believed to have been free of ice. But by the early Oligocene around 25 million years later, ice sheets covered Antarctica and continental ice had developed on Greenland.

"This change from greenhouse to icehouse conditions resulted from decreasing greenhouse gas concentrations and changes in Earth's orbit," said Dr Ian Harding of the University of Southampton's School of Ocean and Earth Science (SOES) at the National Oceanography Centre, Southampton (NOCS): "However, the opening or closing of various marine gateways and shifts in ocean currents may also have influenced regional climate in polar high-latitudes."

The separation of Eurasia and Greenland due to shifting tectonic plates led to the partial or complete submergence of former land barriers such as the Vøring Plateau of the Norwegian continental margin. For the first time, waters could exchange between the Norwegian–Greenland Sea, the Arctic Ocean and the North Atlantic.

Dr Harding and his former PhD student Dr James Eldrett have reconstructed the environmental conditions over the Vøring Plateau over this time period by carefully analysing the fossilised remains of organic debris and cysts of tiny aquatic organisms called dinoflagellates from sediment cores.

"Because different dinoflagellate species are adapted to different surface water conditions, their fossilised remains help us reconstruct past environments," said Dr Harding.

The evidence from the sediments cores suggests the development of shallow marine environments across parts of the Vøring Plateau during the early Eocene. However, the presence of fossilised species that lived in fresh or brackish water indicates that northerly parts of the plateau as well as the crest of the Vøring Escarpment were still above water.

In the late Eocene sediments (around 44 million years old) only marine plankton species were found, indicating that the entire Vøring Plateau had by then subsided and become submerged. This demonstrates that marine connections were established between the various Nordic sea basins much earlier than had previously been thought. These surface water connections may have promoted the increased surface water productivity evidenced by the abundance of planktonic fossils preserved in the sediment cores of this age.

"Increased productivity would have drawn carbon dioxide down from the atmosphere," said Dr Harding: "Because carbon dioxide is a greenhouse gas, this may have contributed to declining global temperatures and led to the early development of continental ice on Greenland in the latest Eocene."

Contact information:

For more information contact the NOCS Press Officer Dr Rory Howlett on +44 (0)23 8059 8490 Email: r.howlett@noc.soton.ac.uk

Scientist contact

Dr Ian Harding: email ich@noc.soton.ac.uk; telephone +44 (0) 23 8059 2071

Publication: Eldrett, J. S. & Harding, I. C. Palynological analyses of Eocene to Oligocene sediments from DSDP Site 338, Outer Vøring Plateau. Marine Micropaleontology 73, 226-240 (2009).

Notes:

The research used samples provided by the Ocean Drilling Program and was funded by the American Association of Stratigraphic Palynologists, The Geological Society of London, The Micropalaeontological Society and the Natural Environment Research Council. Co-author Dr James Eldrett was awarded his doctorate by the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre. He is now at Shell Exploration and Production Ltd.

The National Oceanography Centre, Southampton is the UK's focus for ocean science. It is one of the world's leading institutions devoted to research, teaching and technology development in ocean and Earth science. Over 500 research scientists, lecturing, support and seagoing staff are based at the centre's purpose-built waterside campus in Southampton along with over 700 undergraduate and postgraduate students.

The National Oceanography Centre, Southampton is a collaboration between the University of Southampton and the Natural Environment Research Council. The NERC royal research ships RRS James Cook and RRS Discovery are based at NOCS as is the National Marine Equipment Pool which includes Autosub and Isis, two of the world's deepest diving research vehicles.

Dr Rory Howlett | EurekAlert!
Further information:
http://www.soton.ac.uk

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 >>>