*Craig J Rodger¹、Daniel H. Mac Manus¹、Michael Dalzell ²、Alan W. P. Thomson³、Tim Divett ¹、Mark A. Clilverd ⁵、Tanja Petersen ⁴、Moritz Wolf⁶ (1.Department of Physics, University of Otago, New Zealand、2.Transpower New Zealand Limited, New Zealand、3.British Geological Survey, United Kingdom、4.GNS Science, New Zealand、5.British Antarctic Survey, United Kingdom、6.Munich University for Applied Science, Munich, Germany)