Abyssal circulation of the southeastern Pacific and some geological implications
Abyssal circulation of the southeastern Pacific and some geological implications
复制标题
东南太平洋的深海环流和一些地质意义
DOI：
10.1029/jc081i006p01163
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发表时间：
1976
影响因子：
--
通讯作者：
P. Lonsdale
中科院分区：
文献类型：
--
作者：
P. Lonsdale
东太平洋海隆以东的太平洋深海环流是根据水文学数据推导出来的，并得到一些直接电流测量的支持。公认的两条主要水流路径：穿过智利隆起进入智利盆地，然后向北进入秘鲁盆地和巴拿马盆地；向东穿过东太平洋隆起进入危地马拉盆地并进入鲍尔盆地。转换断层槽是水流穿越隆起的重要通道，秘鲁-智利海沟是流入秘鲁和巴拿马盆地的主要通道。流经赤道附近东太平洋海隆的深水，其温度结构与智利盆地南部相似，但含盐量较低，氧气浓度也较低。沿着两条流动路径，由于垂直混合（在基台附近加剧）、地热加热（集中在活跃的扩散中心）和有机物的原位腐烂（特别是在生产性地表水之下），底层水变得更温暖、含盐量更少、含氧量更少。深海环流的区域模式可能部分控制含金属中上层沉积物（包括细粒沉淀物和锰结核）的分布和钙质沉积物的溶解速率。当深层温盐流在盆地之间的n条通道中加速时，它深深地侵蚀了海底并以床质形式输送沉积物。在其中一个通道中测得的稳定电流超过 30 厘米/秒。
The abyssal circulation of the Pacific Ocean east of the East Pacific Rise is deduced from hydrographic data, supported by a few direct current measurements. Two main flow paths are recognized: across the Chile Rise into the Chile Basin, and thence northward into the Peru Basin and Panama Basin; and eastward across the East Pacific Rise into the Guatemala Basin and into Bauer Basin. Transform fault troughs are important passages allowing flow across the rises, and the Peru-Chile Trench is the principal channel for inflow to the Peru and Panama basins. The deep water that flows across the East Pacific Rise near the equator has a similar temperature structure to that in the southern Chile Basin, but it is less saline and has lower oxygen concentrations. Along both flow paths the bottom waters become warmer, less saline, and less oxygenated as a result of vertical mixing (intensified near sills), geothermal heating (concentrated at active spreading centers) and in situ decay of organic matter (especially beneath productive surface waters). The regional pattern of abyssal circulation may partly control the distribution of metalliferous pelagic sediments (including both fine-grained precipitates and manganese nodules) and the rates of dissolution of calcareous sediments. Where the deep thermohaline flow is accelerated in n rrow passages between basins it has deeply eroded the sea floor and transports sediment as bed load. Steady currents measured in one of these passages exceeded 30 cm/s.