1. Ocean University of China, College and Marine Geosciences and Key Lab of Submarine Geosciences and Prospecting Techniques (MOE), Qingdao, China.
2. Utrecht University, Mathematical Institute, Utrecht, The Netherlands.
3. Ocean University of China, College and Marine Geosciences and Key Lab of Submarine Geosciences and Prospecting Techniques (MOE), Qingdao, China and National Laboratory for Marine Science and Technology (Qingdao), Evaluation and Detection Technology Laboratory of Marine Mineral Resources, China.
4. Ocean University of China, College and Marine Geosciences and Key Lab of Submarine Geosciences and Prospecting Techniques (MOE), Qingdao, China. (corresponding author)