Collaborative Research: Examination of the Potential Sources for the Mid-Water Silica Anomaly in the NE Pacific

合作研究：检查东北太平洋中层水体二氧化硅异常的潜在来源

• 批准号: 0452088
• 负责人: Douglas Hammond
• 金额: $ 9.61万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0452088&HistoricalAwards=false
• 关键词: Collaborative; Research; Examination; Potential; Sources

ABSTRACTOCE-0452565 / OCE-0452088Previous studies have shown that the North Pacific contains the highest deep-water concentrations of dissolved silica in the world ocean, and Cascadia Basin appears to be the source region for this global-scale anomaly. Data compilations indicate that a .plume. of dissolved silica originates from within this small marginal Basin, which can be traced for several thousand miles, from an origin in the NE Pacific to the Hawaiian Ridge in the south and almost to Siberia in the west. Box model calculations based on compiled data in the area indicate that the North Pacific deep-water silica anomaly requires a flux from Cascadia Basin of nearly 2 Tmols/year to sustain the observed concentration levels. If correct, this dissolved silica flux is an astonishing 40% of the total riverine silica input to the oceans, but this interpretation requires substantial verification. Although there are several identified sources for dissolved silica within the Basin, including ridge-axis vent fields, ridge-flank hydrothermal circulation, compression of sediments at the accretionary wedge and the upward diffusive flux from sediment pore waters, none of these processes, either individually or in aggregate, appear to be adequate to produce the observed deep-water silica anomaly. In this study, researchers at the University of Washington and the University of Southern California will conduct a field program to provide the required spatial distribution of CTD and Niskin/nutrient measurements needed to construct a reasonable silica inventory and geostrophic bottom water flux. They plan to (a) compile all existing CTD/nutrient data from Cascadia Basin, which is substantial in number, but limited in location, (b) add new data from cruises-of-opportunity in 2004, (c) map the geographic distribution and inventory of deep-water silica with 40 new hydrocast profiles from areas not sampled by existing data, (d) use the new data to determine the basin-scale pattern of bottom water circulation and (e) determine the Ge/Si ratios of the bottom water, to distinguish biological from geological source regions. The primary goals of the program are to quantify the flux of dissolved silica into the Basin and identify the source regions that are responsible.Broader Impacts: Large ocean-going field programs at UW support graduate and undergraduate students in their academic research, allow participation of additional non- Oceanography students from UW and from other institutions on the cruises, acquire data for student theses, and provide substantial out-reach in public awareness about scientific research. Further, although Cascadia Basin was poorly sampled by WOCE, the few data collected suggest a disproportionate role for this small basin in determining properties of the entire Pacific Deep Water.

Abstractoce-0452565 / OCE-0452088 PREVIOS研究表明，北太平洋在世界海洋中含有最高水的溶解二氧化硅浓度，而卡斯卡迪亚盆地似乎是该全球尺度异常的来源区域。 数据汇编表明一个.plume。溶解的二氧化硅的源自这个小小的边缘盆地内，可以追溯到几千英里，从东北太平洋的起源到南部的夏威夷山脊，几乎到西西伯利亚。 基于该区域的数据的框模型计算表明，北太平洋深水二氧化硅异常需要Cascadia盆地近2个TMOL/年的通量，以维持观察到的浓度水平。 如果正确的话，这种溶解的二氧化硅通量是对海洋总二氧化硅输入的惊人40％，但是这种解释需要大量验证。 尽管在盆地内有几种确定的溶解二氧化硅的来源，包括脊轴排气场，山脊 - 河流水热循环，积聚楔的沉积物压缩以及与沉积物孔隙水的向上扩散的泛滥，这些过程都不是单独的，要么是单独的，要么在聚集中可以构成良好的硅酸盐。在这项研究中，华盛顿大学和南加州大学的研究人员将开展一项现场计划，以提供CTD和Niskin/Nekin/Nutrient测量的所需空间分布，以构建合理的二氧化硅库存和地质底部水流。他们计划（a）从卡斯卡迪亚盆地收集所有现有的CTD/养分数据，该数据数量很大，但位置有限，（b）在2004年添加了来自商业巡航的新数据，（（c）映射到深水硅胶的地理分布和库存，深水硅胶的地理位置和清单，用40个新的水合物概述，该区域未通过现有数据来确定（d），（d）使用新的水合物，（d）使用新的水合物（d），（d）使用（d）（d）（d），（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d），d（d）deply（D）底部水的GE/Si比率，以区分生物学和地质来源区域。该计划的主要目标是量化溶解的二氧化硅的通量进入盆地，并确定负责的源区域。Broader的影响：UW支持毕业生和本科生的大型海洋领域计划，允许参与UW的其他非海洋学学生的参与，从UW以及从Cureises的其他机构中获取数据，并为学生提供了众多的范围，并提供了众多的范围，并为实质性提供了可观的范围。此外，尽管WOCE对卡斯卡迪亚盆地进行了很少的采样，但收集到的少数数据表明，这个小盆地在确定整个太平洋深水的性质中起着不成比例的作用。