Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Further break-up of Wilkins Ice Shelf

16.06.2008
Wilkins Ice Shelf, Antarctica, is further breaking up. After a two month rest period, a new break-up has started and is still continuing, as researchers from the University of Muenster and Bonn report. For the first time a break-up event in Antarctic winter is documented. In March 2008 a spectacularly break-up at the Wilkins Ice Shelf already hit the headlines.

Wilkins Ice Shelf is located on the western side of the Antarctic Peninsula at about 70°S, about 100km south of the southern tip of South America. Dr. Angelika Humbert of the Polar Geophysics Research Group of the University of Muenster and her colleague Dr. Matthias Braun of the Center for Remote Sensing of Land Surfaces of the University of Bonn have monitored the events, which started on 30 May 2008.

The team of researchers is tracking the development in a sensitive region, which connect the Wilkins Ice Shelf to Charcot and Latady Islands, since years by means of satellite images of the European Space Agency (ESA) and the German Aerospace Center (DLR).

The formerly about 15 km wide connection between the islands was reduced in its width to now only about 3 km. Satellite images show on the remaining ice plate an arched fracture, making it most likely that the remaining plate will disrupt completely in the next few days. The consequences for the entire ice shelf are not yet foreseeable.

The newly broken up ice mass was already a year ago littered with small fractures. 'The real damage was done already then' is Angelika Humbert pointing up, who already reported with her colleague about the reasons for the fracturing: buoyancy forces due to different ice thicknesses caused bending stresses in the ice. These led to fractures, which spread abruptly.

Subsequently, the unstable ice is breaking at a later point - as it happened the second time in a few month. Ice shelves on the Antarctic Peninsula are floating on the sea and are sandwiched between a warming ocean and increasing surface air temperatures. A possible connection to the extraordinary warming rates observed along the Antarctic Peninsula may exist by promoting melting processes on the underside of the ice.

The recent break-up shows that melt water, which was long in believed to cause as solely factor ice shelf break-up, played no role in the recent event: in the current Antarctic winter the surface of the Wilkins Ice Shelf is frozen completely.At the moment, the largest stresses in the ice are likely due to ice creep, the deformation of ice under its own weight. These stresses might have drawn the fracture faces apart and caused them to cut through. The break-up was running this time completely different from the February 2008 event: while that time the icebergs were calving directly from the ice front, this time the ice mass is breaking up from the inside out. Small sliver icebergs capsize and push the ice mass in front of it outside.

Norbert Frie | idw
Further information:
http://www.uni-muenster.de/
http://earth.uni-muenster.de/polarhomepage/info.shtml

More articles from Earth Sciences:

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

nachricht Drones survey African wildlife
11.07.2018 | Schweizerischer Nationalfonds SNF

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

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

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>