1. Institut für Geowissenschaften Universität Potsdam Potsdam Germany
2. Department of Geosciences University of Arizona AZ Tucson USA
3. Now at the Institute of Earth Surface Dynamics University of Lausanne Lausanne Switzerland
4. School of Geology and Geophysics University of Oklahoma OK Norman USA
5. Instituto Geofísico Escuela Politécnica Nacional Quito Ecuador