...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Barium stable isotopes in the global ocean: Tracer of Ba inputs and utilization
【24h】

Barium stable isotopes in the global ocean: Tracer of Ba inputs and utilization

机译：全球海洋钡稳定同位素：BA投入和利用的示踪剂

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Barium has been used as a biogeochernical tracer for alkalinity, productivity, and riverine inputs in the ocean, but its oceanic cycle remains poorly constrained. Barium stable isotope measurements may improve the use of Ba as a tracer and better constrain the cycling of Ba, but data are only available in limited regions of the oceans. In this study, we present dissolved seawater Ba isotopic compositions in a sample collection spanning the North Atlantic, South Atlantic, North Pacific and Southern Oceans. Compiled global upper-ocean [Ba] data show a relatively constant [Ba] (35-45 nM) in the near-surface waters throughout the global ocean, with the exception of areas near river inputs or strong upwelling. The relatively uniform distribution of [Ba] in the upper ocean seawater indicates that Ba removal is slow relative to supply and mixing, and implies that near-surface Ba isotope values are controlled by basin-scale balances rather than by regional or short-term processes. Seawater Ba isotopic compositions show a large variation of delta Ba-138/134 values ranging from 0.24 to 0.65%, and a tight relationship with [Ba]. This global relationship can be simply modelled assuming a primary deep Southern Ocean source for Ba to yield a maximum isotope fractionation of alpha = 1.00058 +/- 0.00010 (alpha = Ba-138/134(seawater)/Ba-138/134(particle)). This suggested isotope fractionation during Ba removal from seawater is larger than implied by laboratory measurement during barite formation, suggesting additional fractionating phases or a two-stage fractionation process. Riverine input from the Rio de la Plata to the South Atlantic has a signature of delta Ba-138/134 = -0.06-0.11%, which is too light to explain the heavy values (>0.58%) observed in the surface open ocean. Globally, the Ba isotope composition of the upper ocean waters is correlated with the fraction of Ba utilization at the basin scale (which varies from <15 to 70% at sites studied here). In the deep Atlantic Ocean, distinct delta Ba-138/134 signals in the northern sourced (approximate to 0.45%) and the southern-sourced water (approximate to 0.25%) trace mixing and allow identification of non-conservative behaviour of Ba, reflecting additional inputs or sinks of Ba during transport (most likely addition from sediment or hydrothermal). Ba isotopes may be useful to trace such inputs in the present and past ocean. (C) 2017 Elsevier B.V. All rights reserved.
机译：钡被用作碱度，生产力和海洋中的河流输入的biogeochernical示踪剂，但其海洋循环仍然受到限制甚少。钡稳定同位素测量可以提高使用钡作为示踪剂，更好地约束巴的循环，但数据仅在海洋中的有限地区。在这项研究中，我们提出一个样本采集横跨北大西洋，南大西洋，北太平洋和南大洋海水溶解巴同位素组成。编译全球上层海洋[巴]的数据显示在近地表水的相对恒定的[巴]（35-45 nm）的整个全球海洋，随着近江输入或强上升流区域中的异常。的[巴]的相对均匀的分布在上层海洋海水表示的Ba去除是相对于供给和混合慢，意味着近表面的Ba同位素值由流域尺度余额而不是由区域或短期过程控制。海水的Ba同位素组合物显示出增量的Ba-134分之138值范围从0.24到0.65％的大的变化，并与[巴]的紧密关系。这个全局的关系可以简单地建模假设初级深南冰洋源Ba的，得到的α的最大同位素分馏= 1.00058 0.00010 +/-（阿尔法=钡-138/134（海水）/ BA-138/134（颗粒） ）。从海水中的Ba移除期间这提示同位素分馏比重晶石形成期间通过实验室测量暗示，提示附加的分馏阶段或两阶段分馏工艺大。从拉普拉南大西洋河流输入具有三角形的Ba-134分之138= -0.06-0.11％，这是太轻解释在表面开放海洋中观察到的重值（> 0.58％）的签名。在全球范围内，上部海水的巴同位素组合物用Ba利用在流域分的分数（其从在这里所研究位点<15〜70％之间变化）相关。在深大西洋，不同增量的Ba-134分之138信号在北部源（近似0.45％）和南部来源的水（大约0.25％）微量混合和允许的钡的非保守行为识别，反射的附加输入或在运输过程中的Ba的汇（最有可能从除沉淀物或水热）。巴同位素可以是在当前和过去的海洋跟踪这样的输入是有用的。 （c）2017年Elsevier B.V.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号