Expedition | 502

International Ocean Drilling Programme (IODP³) Expedition 502 plans to drill the outer rise area of the Japan Trench, where the sediment layer above the acoustic basement is unusually thin. There is a hypothesis that this thin sediment is caused by basalt intrusions or lava flows related to a type of volcanic activity called petit-spot magmatism. The goal of this expedition is to determine if this volcanic activity is more widespread than previously thought. If confirmed, it could significantly influence how subduction zones work, including earthquake processes, volcanic activity, and global chemical cycles. This research will help understand the role of petit-spot magmatism and its impact on the Earth’s systems.