3-D magnetic inversion modeling analysis in TA19-1 seamount of the Lau basin by the iterative reweighted least square method

Abstract

We performed the marine magnetic and the bathymetry survey in the Lau basin for finding the submarine hydrothermal deposits in October 2009. We acquired magnetic and bathymetry datasets by using Overhouser Proton Magnetometer SeaSPY(Marine Magnetics Co.) and Multi-Beam Echo Sounder EM120(Kongsberg Co.). We conducted the data processing to obtain detailed seabed topography, magnetic anomaly and reduction to the pole(RTP). By 3-D magnetic inversion from Jung’s prevous study(2013), we calculated the magnetic susceptibility distribution of the TA19-1 seamount area using the RTP data. From the modeling, we derived the appropriate scale factor for the use of depth weight and setting magnetic susceptibility. Compared between the final modeled result and RTP values in this study, they are generally similar to the each other. But the input values and the modeled values are have slightly little difference. This difference is expected to have been caused by various and complex stratovolcanos, misunderstanding of regional geology distribution, modeling design(various scalar factor, depth weight and magnetic susceptibility), limited vertical resolution from non-uniqueness in potential field and etc. We can expect to have the better results of advanced modeling design with more geological survey data.Magnetics Co.) and Multi-Beam Echo Sounder EM120(Kongsberg Co.). We conducted the data processing to obtain detailed seabed topography, magnetic anomaly and reduction to the pole(RTP). By 3-D magnetic inversion from Jung’s prevous study(2013), we calculated the magnetic susceptibility distribution of the TA19-1 seamount area using the RTP data. From the modeling, we derived the appropriate scale factor for the use of depth weight and setting magnetic susceptibility. Compared between the final modeled result and RTP values in this study, they are generally similar to the each other. But the input values and the modeled values are have slightly little difference. This difference is expected to have been caused by various and complex stratovolcanos, misunderstanding of regional geology distribution, modeling design(various scalar factor, depth weight and magnetic susceptibility), limited vertical resolution from non-uniqueness in potential field and etc. We can expect to have the better results of advanced modeling design with more geological survey data.