Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


How does ice flow?

Scientists from the Alfred Wegener Institute present first results of a new measurement method in Antarctica

Currently the yearly General Assembly of the European Geological Union takes place in Vienna, Austria. Dr. Olaf Eisen from the German Alfred Wegener Institute presents results from an environmentally friendly measurement method that he and his colleagues used on an Antarctic ice-shelf for the first time in early 2010. It supplies data that are input to models for the ice mass balance and thus permit better forecasting of future changes in the sea level.

The quality of scientific models depends to a decisive degree on the available database. Therefore members of a young investigators group supported by the German Research Foundation (DFG) now applied a special geophysical measurement method, vibroseismics, for data collection in the Antarctic for the first time. “By means of vibroseismic measurements, we would like to find out more about the structure of the ice and thus about the flow characteristics of the Antarctic ice sheet,” explains Dr. Olaf Eisen from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. He is head of the LIMPICS young investigators group (Linking micro-physical properties to macro features in ice sheets with geophysical techniques).

Eisen now presents first results from geophysical measurement campaign in the Antarctic on the international conference. The objective of the expedition was to determine the internal structure of an ice sheet from its surface by means of geophysical methods. The cooperation partners are the Universities of Bergen (Norway), Swansea (Wales, UK), Innsbruck (Austria) and Heidelberg (Germany) and the Commission for Glaciology of the Bavarian Academy of Sciences and Humanities. For test purposes vibroseismics was used along with proven explosive seismic methods for the first time on an ice sheet.

One of the problems involved in the application of seismic methods on ice sheets is the very porous firn layer, which may be 50 to 100 metres thick. Explosive seismics involves drilling a hole, approximately 10 to 20 metres deep, into the firn to achieve a better coupling between the explosive charge and the surrounding firn or ice. Drilling takes a lot of time and permits only slow progress along the seismic profiles. Vibroseismics entails the generation of seismic waves directly on the surface. For this purpose the vibrator pad of a 16-ton vibroseis truck of the University of Bergen is pressed onto the precompressed firn and set into operation at a defined vibration rate. In contrast to explosive seismic methods, the excited seismic signal is known and can be repeatedly generated as frequently as desired, leading in the end to improved data quality. However, the loss of seismic energy in the porous firn is a disadvantage. Therefore, the scientists compare the explosive seismic and vibroseismic methods quantitatively and in this way want determine how much energy is propagating from the surface through the ice and reflected back to the surface. First data analyses show that vibroseismics is coequal to the classic explosive seismics concerning the amplitude of the waves sent into deeper snow and ice layers. An explicit advantage is the lower effort and thus less time and energy the scientists spend to measure seismic profiles now.

Yngve Kristoffersen, professor of geophysics at the University of Bergen, who provides the vibroseismic equipment, explains: “The successful pilot study opens up a new era for efficient and more environmentally friendly methods for obtaining seismic information on the internal structure of the ice and the bedrock underneath it. This would extend our knowledge about how the ice sheet moves across the bedrock and about the geological structure of the rock under the ice.” Furthermore, in the coming years this method will be applied during pre-site surveys of future geological drill sites under ice shelves, which will contribute to a better understanding of climate history.

The Alfred Wegener Institute conducts research in the Arctic, Antarctic and oceans of the high and mid latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctic. The Alfred Wegener Institute is one of the sixteen research centres of the Helmholtz Association, the largest scientific organisation in Germany.

Margarete Pauls | idw
Further information:

More articles from Earth Sciences:

nachricht Oasis of life in the ice-covered central Arctic
24.10.2016 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>