Abstract: The seafloor hydrothermal system plays an important role in exchanges of both thermal energy and chemical components between the ocean and Earth crust, which has revolutionized our understanding of deep- sea biological processes. The hydrothermal system in the temperature background stratification was simulated by an axisymmetric model. Simulation results showed that because the plume continued to entrain fluid, the temperature decreased, the plume overshot to the maximum plume rise height in the stratified environment eventually. The plume’s vertical velocity decreased as the plume rose in its center area. Our results also suggested that the maximum plume rise height and plume’s radius at the bottom agreed with the MTT theory. Over time, a laterally spreading intrusion developed above 50 m. In 0-50 m, the plume’s radius remained unchanged. At 1.39 hours, the plume’s radius was less than 30 m; at 100.00 hours, it become 150 m.

Key words: hydrothermal plume, species transport, lateral range, numerical simulation