Transient Electromagnetic Method for Seafloor Massive Sulfide Exploration: Effects of Induced Polarization, Topography and Transmitter Current Waveform

ABSTRACT The marine transient electromagnetic method (TEM) has emerged as a powerful geophysical technique for exploring seafloor massive sulfide (SMS) deposits due to its high sensitivity to conductive mineralization. However, accurate interpretation of marine TEM data is challenged by several factors, including induced polarization (IP) effects, topographic influences and transmitter current waveform characteristics. This study uses three‐dimensional numerical simulations based on synthetic models to investigate these factors and their interactions. Our analysis demonstrates that topography and transmitter waveform characteristics, particularly the current turn‐off time, predominantly distort early‐time signals, whereas IP effects typically influence the late‐time TEM response, distorting the decay curve with a distinctive ‘upturn’ and signal polarity reversal. When these factors interact, the TEM response may be distorted throughout the entire acquisition window, creating compounded interpretation challenges. This work systematically analyses each factor, presents current mitigation strategies and identifies future research directions for improving TEM accuracy in sulfide exploration. The synthesis presented here aims to enhance the reliability of TEM data inversion and interpretation in complex exploration scenarios, ultimately supporting more effective sulfide resource identification and assessment.