Anja Diez

CR Cryospheric Sciences

The 2014 Outstanding Student Poster (OSP) Award is awarded to Anja Diez for the poster/PICO entitled:

Investigation of crystal anisotropy using seismic data from Kohnen Station, Antarctica (Diez, A.; Eisen, O.; Weikusat, I.; Lambrecht, A.; Mayer, C.; Hofstede, C.; Bohlen, T.; Miller, H.)

Click here to download the poster/PICO file.

I did my PhD at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research within the Junior Research Group LIMPICS of Olaf Eisen in cooperation with the Karlsruhe Institute of Technology. We are interested in determining physical properties of the ice with help of geophysical methods, such as radar and seismics. The focus of my work has been on the investigation of the anisotropic ice fabric with seismic waves. In the EGU poster we present a framework to calculate the polycrystal elasticity tensor for different crystal anisotropies from crystal orientation fabric (COF) eigenvalue data. We find good agreement between velocities calculated by this approach and velocities determined from a vertical seismic profiling survey. By combining the seismic with the radar data we are able to identify common reflection signals caused by abrupt changes in COF. Hence, we can separate isochrone radar layers (which are induced by conductivity signals from volcanoes) from COF-induced layers. This is, for instance, important to track layers of equal-age to find suitable future ice-core drill sites.

Publication resulting from the award

Diez, A. and Eisen, O.: Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties, The Cryosphere, 9, 367–384, https://doi.org/10.5194/tc-9-367-2015, 2015.