Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Geoscientists from the Alfred Wegener Institute are back from an expedition to the Labrador Sea

22.07.2009
Indications for volcanic eruptions in the younger geological history found

Scientists from the Alfred Wegener Institute have researched the geology of the seabed in the Labrador Sea on board of the research vessel Maria S. Merian.

They have studied the so-called Eirik Drift at the southern tip of Greenland, a structure of several hundred kilometres length formed like a ridge. They discovered a submarine mountain (seamount) at the south-western fringe of their area of investigation that indicates volcanic eruptions during the past few million years.

The Eirik Drift rises 2,500 m above the surrounding seabed at the southern tip of Greenland. Sediments have been depositing there for the last ten million years, forming a ridge-like structure. These sediments are ablated by ocean currents in the Greenland Sea and deposited in the Labrador Sea. This is also known to be the case with sand displacements caused by ocean currents, for example on Sylt. Caused by changing climate - the transition from warmer times to our current climate - the current drifted and changed its strength. Additionally, icebergs transport rock material from Greenland onto the seabed. Glaciers planed it off the island, and on breaking apart into icebergs, deposited it all over the ocean. Caused by the constantly expanding and melting ice surface during the geological cycles of glacials and interglacials, this material finds its way into the Eirik Drift, too.

Therefore, the Eirik Drift is an archive for the activity of Greenland's western boundary current and the dynamics of Greenland ice cover. Climate changes and current shifts of the last ten million years can be examined here. First results show that the drift shifted strongly to the North and the West. This event took place about 5.6 million years ago. A sediment drift can be observed for the period prior to that, but velocity and path of the current changed strongly. Researchers will be able to further analyse these data by means of computer models in order to describe these changes in more detail.

The researchers discovered something unexpected during the seismic investigation using a recording cable of 3.000 m length: "Surprisingly, an unknown elevation appeared on the images of the subsurface in the western area of the Eirik Drift, which almost breaks through the sediments to the top of the seabed at two places," reports chief scientist Dr Gabriele Uenzelmann-Neben from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. "The sedimentary layers are disturbed," the geophysicist continues. This elevation at the seabed, called Mount Maria S. Merian by the researchers, is about 1.500 m high - approximately as high as the Feldberg in the Black Forest. The seamount was formed by volcanism which pushed sediments upwards. Even the youngest sediment packages are affected by this movement.

It can therefore be concluded that this is a young event have occurred during the last few million years. This result changes the picture of the geological development of the outer part of the Labrador Sea. So far it was assumed that the formation of the seafloor in the Labrador Sea (tectonic activity) ended about 45 million years ago. The discovery of the seamount indicates that the seabed at the exit of the Labrador Sea changed in more recent times. A distinct changing seabed has an enormous impact on the circulation paths of deepwater, which maintains ocean currents like the Gulf Stream.

The expedition of RV Maria S. Merian, operated by the Leitstelle Merian/Meteor of the University of Hamburg, began June 17th 2009 in Reykjavik where it also ended July 13th.

Further information on this research project: http://www.awi.de/en/research/research_divisions/geosciences/geophysics/

projects/marine_geophysics_arctic/eirik_drift/?0=

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 provides international science with important infrastructure, e.g. the research icebreaker Polarstern and research stations in the Arctic and Antarctic. The Alfred Wegener Institute is one of 16 research centres within the Helmholtz Association, Germany's largest scientific organization.

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

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>