Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

RV Polarstern on its way to measurements in the East Siberian Sea

21.08.2008
Research vessel transits the Northwest Passage for the first time ever

German research vessel Polarstern, operated by the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association, transits the Northwest Passage for the first time.

Polarstern left the port of Reykjavik on August 12th, sailed around Greenland on a southern course and is located right now at the beginning of the Northwest Passage. Its destination is the East Siberian Sea where geoscientific measurements at the junction between the Mendeleev Ridge and the East Siberian Shelf are at the focus of the participants of this expedition. The measurements striven for in the framework of the International Polar Year shall help to understand how the undersea ridges and basins were built. This expedition takes the researchers in 68 days around the North Pole because the return voyage is to lead via the Northeast Passage.

The researchers want to clarify the tectonic interrelations on the bottom of the Arctic Ocean in the track of Alfred Wegener, who founded the theory on continental drift in 1915. They employ seismic measurement methods which shall allow a glance at the geological units and sediments. "At the bottom of the sea we find mountains which are about the same height as the Alps," illustrates Chief Scientist Wilfried Jokat. "These are partially overlaid by sediments, so that we have to look beneath the surface to find clues hinting at the geological history of the Mendeleev Ridge," he explains further.

Where the Mendeleev Ridge meets the East Siberian Shelf, very old layers can be found at the surface of the sea bottom. If the researchers find such places by means of the equipment on board Polarstern, they will try to retrieve cores with a gravity corer. 50 million years old rocks crop out at these places; usually, only layers of the upper 10 to 15 metres can be cored with a gravity corer, which only shows layers about 1 million years old. Both sediment cores and sediment profiles shall be used to further a proposal for future Arctic depth drilling. Within the framework of the International Ocean Drilling Program (IODP), a long drilling core shall be gained which is anticipated by researchers worldwide. It will give new insights into Arctic geological history of the last 100 million years.

Furthermore, there are areas with a high rate of sedimentation in the East Siberian Sea. If the researchers manage to retrieve cores from these sediments, it will help to conclude climate history of the younger geological past. For example, the rate of organic carbon in sediment cores hints at biological activity, and researchers can reconstruct temperature and ice cover up to one million years ago.

Presently, organic carbon reaches the Arctic Ocean via rivers as well. For this reason oceanographers are interested in the East Siberian Sea. Similar to former cruise stages, they sample water and monitor temperature, salinity and depth. Additionally, they specify the concentration of terrestrial carbon in the water, by which they are able to calculate from which river the examined water originates and how long it has been on its way. These data shall help to understand climate relevant systems of currents in the Arctic Ocean.

Changes to marine currents also affect the biotic environment. This is why biologists investigate the species assemblage in samples of various regions and depths and compare them with measurements taken in the 1990ies. This way they can deduce, for instance, whether a changing ice cover affects the system's biological productivity. The copepod Oithona similes which lives both in the Arctic and Antarctic Ocean and also in the North Sea will be investigated in more detail. The researchers want to conduct experiments on board to see how they successfully reproduce in these different climatic zones.

All of this research is dependent on external factors like weather and, particularly, ice cover. Two months ago it was still uncertain whether Polarstern could transit the Northwest Passage; an alternative measurement program for Greenland Sea had been parked in the drawer. Current satellite pictures show that the Northwest Passage is almost ice free and that it can probably be sailed without big problems. During the expedition, cruise leader Jokat wants to get in contact with Canadian and US-American colleagues who undertake measurements in the Beaufort Sea. They can pass on information which no satellite can provide.

After its journey home through the Northeast Passage, Polarstern will reach Bremerhaven again on October 19th.

The Alfred Wegener Institute carries out research in the Arctic and Antarctic as well as in the high and mid latitude oceans. The institute coordinates German polar research and makes available to international science important infrastructure, e.g. the research icebreaker "Polarstern" and research stations in the Arctic and Antarctic. AWI is one of 15 research centres within the Helmholtz Association, Germany's largest scientific organization.

Margarete Pauls | idw
Further information:
http://www.awi.de/

More articles from Earth Sciences:

nachricht NASA looks to solar eclipse to help understand Earth's energy system
21.07.2017 | NASA/Goddard Space Flight Center

nachricht Scientists shed light on carbon's descent into the deep Earth
19.07.2017 | European Synchrotron Radiation Facility

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>