1. Chair of Geothermal Science and Technology, Technische Univ. Darmstadt, 64287 Darmstadt, DE, e-mail: anbergen@geo.tu-darmstadt.de
2. Frank GeoConsult GmbH, 22085 Hamburg, DE.
3. Chair of Geotechnics and Geothermal Science, Hochschule Ostwestfalen-Lippe, 37671 Höxter, DE.
4. Chair of Geothermal Science and Technology, Technische Univ. Darmstadt, 64287 Darmstadt, DE.