1. Swiss Seismological Service (SED) , ETH Zürich, Sonneggstrasse 5, 8092 Zürich , Switzerland
2. Geological Institute and Oeschger Centre for Climate Change Research, University of Bern , Baltzerstrasse 1+3, 3012 Bern , Switzerland
3. Department of Civil and Architectural Engineering, Faculty of Engineering and Technology, University of Buea , Buea , Cameroon
4. DMT GmbH Co. KG , Am TUV 1, 45307 Essen , Germany