The 24th IAHR-APD Congress (24th IAHR-APD Congress)

78 / 2023-12-31 14:14:18

Numerical simulation of seafloor hydrothermal circulation in Tianxiu hydrothermal zone

Seafloor hydrothermal circulation,Tianxiu hydrothermal zone,Numerical simulation,Metallogenic elements

Seafloor hydrothermal circulation is an important process of mass transport and energy conversion. When the high temperature seafloor fluids and low temperature seawater mix, the metallogenic elements produce chemical reactions, form hydrothermal mineral precipitation and settle near the vents, that causing the change of the seabed morphology. However, the understanding of how metallogenic elements enter the hydrothermal circulation in the ocean crust and reach the hydrothermal vents is far from sufficient.

Our research takes the structurally controlled Tianxiu hydrothermal zone as a typical example to explore the concentration distribution of metallogenic elements in the process of hydrothermal circulation. The Tianxiu hydrothermal zone is the first hydrothermal system with ultramafic rock as the surrounding rock found on the Karlsberg Ridge, with an average water depth of about 3450m.

By means of numerical simulation, the finite volume method was used to discretize the governing equations. Given appropriate initial and boundary conditions, and retrieve the thermodynamic parameters of fluids, such as specific heat capacity by referring to the look-up tables, the flow rate field, temperature field, pressure field and elements concentration field of the seafloor hydrothermal circulation in the Tianxiu hydrothermal zone were calculated and solved. Based on this, the mechanism of seafloor hydrothermal circulation and the transport path of metallogenic elements in the Tianxiu hydrothermal zone are discussed and the possible influence on the seabed geomorphology is discussed.