1. a Laboratoire de Géologie, Ecole Normale Supérieure (ENS) , 24 rue Lhomond, 75231, Paris Cedex 05, France
2. b Remote Sensing and G.I.S. Applications Laboratory, Aristotle University of Thessaloniki , 54124, Thessaloniki, Greece
3. c Faculty of Rural and Surveying Engineering, Aristotle University of Thessaloniki , 54124, Thessaloniki, Greece