Halvfarryggen
Halvfarryggen is a local ice dome in Antarctica. It lies south-east of the Neumayer III, the German Antarctic station, and defines the boundary of the Ekströmisen catchement, the ice shelf on which Neumayer is located. Three ridges come together near the ice dome of Halvfarryggen. As it is located quite close to Neumayer it seemed a suitable site to test the new equipment. From airborne radar data it is known that upwarping internal layers exist, a so-called Raymond bump or isochrone arch. The special characteristics of the isochrones' geometry are an indication that anisotropies of the crystal orientation fabric (Martin et al., 2009) of ice might exist at Halvfarryggen. So it is a place where interesting glaciological features can be observed.
Seismic survey
Within the Antarctic field trip in January/February 2010 ground-penetrating radar as well was seismic measurements were carried out on Halvfarryggen. The seismic line was shot on top of the dome with a length of 1455 m. As a source we employed explosives in about 10 m deep boreholes.
Seismics - internal layers
At Halvfarryggen internal layers were observed within the ice by using reflection seismics. These internal reflection horizons are due to a change in seismic velocity, which is most likely caused by a change in the crystal orientation fabric (A. Diez, 2010). One strong internal reflector (0.46 s) can be seen just above the glacier bed. The internal reflectors above are a bit weaker.
