Objective The western slope of the Okinawa trough has been considered to experience important methane seep activities.Abundant terrigenous sediments supply and widely developed normal faults make this area an ideal place for methane production,methane fluids migration and associated anaerobic oxidation of methane.However,few studies have been performed to reveal the methane seep activities via pore water geochemical studies in this area.In this study,we present comprehensive geochemical Objective The western slope of the Okinawa trough has been considered to experience important methane seep activities. Abundant terrigenous sediments supply and widely developed normal faults make this area an ideal place for methane production, methane fluids migration and associated anaerobic oxidation of methane. studies have been performed to reveal the methane seep activities via pore water geochemical studies in this area. this study, we present comprehensive geochemical