1. Key Laboratory of Earth Exploration and Information Technology, Ministry of Education, Chengdu University of Technology, Chengdu, Sichuan, China
2. Department of Earth and Ocean Dynamics, University of Barcelona, Barcelona, Spain
3. Departamento de Física de la Tierra y Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain
4. 3D Consulting-GEO GmbH, Berlin, Germany