基于实测影像的深海热液羽流流场与物质能量输入特性反演研究

Flow fields and outputs of the hydrothermal plume at the Wocan-1 field based on an in-situ video

深海热液羽流是岩石圈与水圈进行物质能量交换的关键媒介,对海洋元素循环和海水化学成分的演化有重要影响.本研究基于实测影像资料对西北印度洋卧蚕-1号热液区热液喷口羽流进行了定量分析,以区域互相关算法为基础计算了热液羽流的流场结构,并进一步估算了卧蚕-1号“火焰山”热液喷口释放的热量和物质通量.结果表明,热液羽流中心线上的垂向速度在初始动量和浮力通量的共同作用下随羽流上升呈增大趋势,羽流中心线最大垂向速度约15.5 cm/s,最大水平速度约10.3 cm/s.受卷吸和边界剪切作用,热液羽流体积流量随上升高度增加近似线性增加.经估算,该喷口向海洋输入的热量约1.35±0.11 MW,所释放的Fe元素约3661±323 kg/a.研究结果为慢速扩张洋脊深海热液羽流动力特性和热液区物质与能量交换提供了科学参考依据.

Deep-sea hydrothermal plumes are an essential medium for exchanging the heat and elements between the lithosphere and hydrosphere and contribute to elemental cycling and marine chemistry evolution. In this paper, based on field video footage of a black smoker recorded at the Wocan-1 hydrothermal field on the slow-spreading Carlsberg Ridge in the northwestern Indian Ocean, the flow fields of the “Huoyanshan” hydrothermal plume were calculated using a cross-correlation algorithm. In addition, the heat and chemical outputs of the hydrothermal vent are investigated using the estimated source volume flux and fluid properties obtained from in-situ measurements. The results reveal that as the plume rises, the vertical velocity along the plume centerline increases, reaching a maximum value of approximately 15.5 cm/s. This tendency is attributed to the combined effect of initial momentum flux and buoyancy flux. The maximum horizontal velocity along the plume centerline is approximately 10.3 cm/s, indicating a strong deep ocean current on the Carlsberg Ridge. Due to plume entrainment, the volume flux of the hydrothermal vent linearly increases with increasing plume rise. Furthermore, the heat and iron outputs from the “Huoyanshan” hydrothermal vent were estimated as1.35±0.11 MW and 3661±323 kg/a, respectively. These results provide valuable insights into the plume dynamics of submarine hydrothermal vents and the deep-sea thermal and elements balance.