Preface Dedicated volume of IOP conference series journal IOP Earth and Environmental Sciences contains the papers presented in the third "World Multidisciplinary Earth Sciences Symposium", which was held in Hotel Duo in the city of romance Prague (Czech Republic) during 11-15 September 2017. The World Multidisciplinary Earth Sciences Symposium (WMESS) has become a popular international event with participants from more than 50 countries, where experienced scientists, experts, university teachers and young researchers have the opportunity to discuss topics related to geosciences. Traditionally, this year's symposium had a very interesting scientific program supplemented with rich social events and geological field trip to the old mining city Přibram
