Abstract:
Submarine mud diapirs and mud volcanoes are of great significance to the study of deep sea geochemical processes and global carbon cycle, the exploration of oil and gas hydrate resources and neotectonic activities. In this paper, the characteristics of mud diapir and mud volcanoes on the western slope of the Okinawa Trough are described and summarized with the geophysical data of high-resolution multi-channel seismic, sub-bottom profiling and multi-beam bathymetry survey. A large number of mud diapirs and mud volcanoes have been observed on the western slope of Okinawa Trough, mostly in the areas with strong fault activities. With the movement of mud diapirs and the migration of methane fluid, mud volcanoes and gas chimneys are commonly formed on the seafloor, mostly on the upper part of mud diapirs, with strong amplitude anomalies on the two wings and low frequency inside, which proves that the formation of mud diapirs and mud volcanoes are closely related to methane fluid activities. The dynamic evolution of mud volcanoes and mud diapirs on the western slope of the Okinawa Trough mainly includes three types: the weak structural zone formed by regional tension, the overpressure and buoyancy zone caused by rapid deposition, and the type formed by fluid driving.