Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

200,000-year environmental history of continental shelf based on a deep-sea core from Okinawa Trough

26.09.2013
A new research paper shows that a great number of nearby terrigenous pollen and charcoal have been found from the deep-sea sediments of the last 200 kyrs in Okinawa Trough.

It is tesitfied that the continental shelf of the East China Sea was exposed and covered with the huge wetland and grassland ecosystems during the the last two glacial periods.


This shows terrigenous palynomorphs of short-distance transportation: light microscope and scanning electron microscope photos of pollen and spore, plant debris and charcoals.

Credit: © Science China Press

They discovered that the variation of terrestrial sources is concordent with global glacial volume and sea-level changes at orbital-scale since 200 kyrs before present. Their work, entitled "A ~200 ka pollen record from Okinawa Trough: Paleoenvironment reconstruction of glacial-interglacial cycles", was published in SCIENCE CHINA Earth Sciences.2013, Vol 56 (doi: 10.1007/s11430-013-4619-0)

This research work concerns mainly the Quaternary environment and global chages based on pollen analysis from a deep-sea core in Okinawa Trough. The project was directed by Department of Earth Sciences, Sun Yat-sen University, with colaboration of University Claude Bernard-Lyon 1 and Laboratory of Climate and Environment Sciences in Gif-sur-Yvette. The first author is professor ZHENG Zhuo from Sun Yat-sen University. Their research work was supported by the National Natural Science Foundation of China (grant no. 40772113, 41072128).

The discoreries show that terrestrial-source materials vary greatly during the transition of glacial and interglacial periods, proving the sensitive response on the global ice volume and sea-level changes. This deep-sea record has firstly documented high percentage of sedge, grass and many freshwater algaes in the glacial interval, which indicates that the offshore distance of Okinawa Trough has obviously shortened due to the exposed continental shelf during the glacial stages.

The vegetation on the exposed continental shelf was dominated by intrazonal communities such as halophyte grasslands and freshwater wetlands. New evidence demonstrated that the fundamental changes of sediment sources in Okinawa Trough since ~200 ka BP were affected by combine factors including the offshore coastline distance, monsoon variability and sea-level changes.

This new research provides an oldest record of Quaternry environment reconstruction so far in the Okinawa Trough. It has a great scientific significance on highlighting the evolution history of continental shelf extension, the tracing of the sediment source areas of the Okinawa Trough and global climate changes since the last 200 kyrs.

See the article: Zheng Z, Huang K Y, Deng Y, Cao L L, Yu S H, Suc J P, Berne S, Guichard F., A ~200 ka pollen record from Okinawa Trough: Paleoenvironment reconstruction of glacial-interglacial cycles. SCI CHINA Earth Sci, 2013 Vol. 56 (doi: 10.1007/s11430-013-4619-0)

http://earth.scichina.com:8080/sciDe/EN/abstract/abstract511107.shtml#

Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 50 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.

ZHENG Zhuo | EurekAlert!
Further information:
http://earth.scichina.com:8080/sciDe/EN/abstract/abstract511107.shtml#

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>