Geophysics becomes female
Charlotte Krawczyk first German geophysics professorRead out
When Charlotte Krawczyk is looking for disturbances with sound waves, there is no doubt that a skeptical dowser is at work. On the contrary, the scientist at the Technical University (TU) Berlin "uses the methods of her discipline to" illuminate "the interior of the Earth's structure, look for groundwater or places where geothermal energy can best be extracted. But Krawczyk does not only cause a sensation with her excellent reputation among specialist colleagues, but also because of her job: For the first time, a woman in Germany has been awarded a chair in geophysics. This science is still a domain of men, even the proportion of female students is vanishingly small.
With sound waves, the 42-year-old has already worked at the GeoForschungsZentrum (GFZ) in Potsdam: Vibrates a large plate on the ground a little up and down, create sound waves in the underground. These waves travel at different speeds in the materials of the Earth's interior, in sandstone they reach only five kilometers per second, while the sound waves in rock at six to eight kilometers per second progress. With many receivers, researchers like Krawczyk now measure how long it takes for an echo of the original sound waves to come back. From the runtime, they can then determine what the underground looks like.
How mountains, volcanoes and earthquakes develop
With these methods, the new geophysics professor at the GFZ, for example, "illuminated" the interior of the earth beneath the Chilean Andes. This was basic research, from which seismologists learn how earth plates collide, pushing up mountains, erupting volcanoes and creating earthquakes. But Krawczyk also wanted to apply their methods in applied research and therefore in the summer of 2007 accepted a call to the Leibniz Institute for Geoscientific Community Tasks (GGA) in Hanover. And since Leibniz professors always teach at universities, the seismologist is now also the chairholder for "geophysics with a focus on seismology" at the TU Berlin. University students have been coming to Hanover time and again to apply their professor's methods in practice.
If Krawczyk at the GFZ with sound waves still structures at depths of many kilometers below the Earth's surface, the 26-headed GGA group now applies the same methods to the first few hundred meters. The researchers are also developing their own special equipment.
Disturbance in the underground in sight
When the geophysicists not only move the plate up and down while creating sound waves, but also vibrate laterally, another type of wave is created, which physicists call "shear waves". When evaluating shear waves, however, not only does a particularly fine image of the subsurface develop, but also quite another: shear waves do not spread in liquids. Thus, the researchers can from the relationship between different wave types also close to the fluid content in the underground. By the term "fluid" geophysicists summarize liquids and their mixtures with rocks and gases as well as melts. display
However, not only groundwater resources or suitable sites for the extraction of natural resources can be detected. With this method Krawczyk also plans to investigate faults in the ground. At such disturbances, layers in the interior of the earth have shifted against each other - the group thus practically observes movements in the interior of the earth.
(idw - Technical University Berlin, 04.09.2007 - DLO)