东北太平洋Explorer Ridge热液羽状流位温浊度异常和物质能量通量估算

Temperature and turbidity anomalies and flux estimation of hydrothermal plume in Explorer Ridge in the Northeast Pacific Ocean

深海热液流体与周围海水之间存在明显的物理和化学差异,通过检测海水的位温浊度异常是探测深海热液活动的重要手段之一。本文采用"海底火山带项目(Submarine Ring of Fire 2002)"拖曳式温盐深测量仪数据资料,研究了东北太平洋Explorer Ridge热液场的水文特征及物质能量通量的释放。结果表明Explorer Ridge热液场热液羽状流中性浮力层所在深度范围约为1 600~1 900m,距离海底的高度约为200m,最大位温、盐度和浊度异常分别为0.04℃、0.004和0.18NTU;中性浮力层热液羽状流帽呈椭圆结构,其长轴与洋中脊线重合,羽状流帽总面积约为27km^2;热液羽状流在中性层范围内存在明显的分层现象,通过经验公式计算得到Explorer Ridge热液场观测范围内热液喷口的总的浮力通量为6.19×10^(-2)m^4/s^3,平均值为2.063×10^(-2)m^4/s^3;总的体积通量为9.884×10^(-2)m^3/s,平均值为3.295×10^(-2)m^3/s;总的热通量为194.9MW,平均值为64.967MW。

There are significant physical and chemical differences between deep-sea hydrothermal fluids and ambient seawater. Detecting the temperature and turbidity anomaly is one of the main methods to explore the hydrothermal fields. Based on the towed CTD dataset of the project of Submarine Ring of Fire 2002, the hydrological characteris- tics and flux discharge of hydrothermal vents in Explorer Ridge were analyzed. The neutral buoyancy layer in Ex- plorer Ridge hydrothermal filed is 1 600 to 1 900 m, about 200 m above the seafloor. The maximums of tempera- ture, salinity and turbidity anomaly are 0.04℃, 0.004 and 0.18 NTU, respectively. The shape of the neutral buoy- ancy layer is approximately elliptical, the major axis overlaps with the ocean ridge, and the total area is about 27 km2. It is found that the neutral buoyancy layer is distinctly layered. It is estimated with empirical formulas that the total buoyancy flux, volume flux and heat flux of the measured hydrothermal vents are 6.19×10^-2m^4/s^3, 9. 884×10^-2 m^3/s and 194.9 MW, respectively, and their average values are 2.063×10^-2 m^4/sa, 3.295×10^-2 m^3/s and 64.967 MW, respectively.