Electromagnetic depth sounding in the Earth's crust: Survey and modeling of the effects of a meteorite impact on the conductivity structure in Southern Germany

More than 14 million years ago a meteorite hit Bavaria and left a huge hole where the Swabian and the Franconian Jura meet in Southern Germany. The impact clearly changed the earth’s surface but what happened in the depth? How deep did the earth got shaken by the impact? And did it affect the crustal conductor? The anisotropy of the crustal conductor in Southern Germany manifests itself in a magnetotelluric phase split. The results of two earlier magnetotelluric surveys in the area, which show a decreased phase split within the crater compared to outside it, indicate a breach in the crustal conductor underneath the crater due to the impact. In order to base the modeling on more solid ground new magnetotelluric data from 14 sites in the region was acquired between June and September 2010 to fill the gaps in the existing data about the area. A simultaneous study on the sediments that filled the crater due to the formation of a lake which does not exist anymore shall contribute some new information on the conductivity of the upper layers. The question arises if it is maybe even possible to identify the direction of the impact with the method. Additionally to a renewed magnetotelluric analysis, geomagnetic depth sounding (GDS) will be used to gain new insights and further improve the model to explain the findings.