Recent progress of the Electro-Magnetic survey to investigate Earth's interior

抄録

During the past five years, the electro magnetic (EM) team of the Japan Agency for Marine Science-Technology (JAMSTEC) has conducted many observations to investigate the crustal and mantle structure in pursuit of various scientific aims in collaboration with other universities and institutes. Around the Nankai subduction zone, we constructed a crustal and regional resistivity model, and detected the low resistivity zone with subduction. Moreover, we developed new geophysical survey tools—the small ocean bottom electro magnetometer (OBEM) and the deep-towed DC resistivity survey system—to investigate the shallow crustal structure. We also conducted an ocean bottom EM array study in the Philippine Sea and other areas to investigate the mantle structure using long-term OBEMs, thereby obtaining high-quality EM data.