Wenping Yin, China University of Mining and Technology, China; Yong Xue, China University of Mining and Technology, University of Derby, China; Chong Niu, China University of Mining and Technology, Shandong GEO-Surveying and Mapping Institute, China; Peng Wang, Pei Li, Botao He, Junfeng Xu, Huping Hou, China University of Mining and Technology, China; Costas Varotsos, National and Kapodistrian University of Athens, Greece