Assessing the effects of calcite saturation on the benthic foraminiferal Mg/Ca-temperature relationship using a homothermal depth transect in the Norwegian Sea

使用挪威海恒温深度样线评估方解石饱和度对底栖有孔虫 Mg/Ca-温度关系的影响

• 批准号: 0341412
• 负责人: Yair Rosenthal
• 金额: $ 22.17万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0341412&HistoricalAwards=false
• 关键词: Assessing; effects; calcite; saturation; benthic

Under this award the PIs will be address the question: What is the effect of calcite saturation on the Mg/Ca - temperature relationship in benthic foraminifera?They propose an 11 day cruise in the Norwegian Sea to collect about 30 multi-cores and 15 giant gravity cores that cover a range of calcite saturation levels at constant temperature and salinity. Benthic foraminiferal Mg/Ca from lightly saturated waters display a steep decrease with increasing water depth. The current global Mg/Ca-temperature relationship can only explain a fraction of the decrease, leading to the hypothesis that the degree of calcite saturation also affects benthic foraminiferal Mg/Ca at the low temperatures typical of themajority of the deep ocean. The depth transect from the homothermal and homohaline Norwegian Sea, that was previously studied by Mackensen et al., (1985) provides an ideal opportunity not only to test the hypothesis, but also to quantify the Mg/Ca - calcite saturation relationship at low temperatures. The PI propose to reoccupy the sites that were used for the Mackensen et al. 1985 faunal study (). Based on that study, they expect a high abundance of live benthic foraminifera. To further test their hypothesis they propose studying two down-core records (one spanning the HL-LGM transition at 150 yr resolution and one record spanning 0 to 35 ka at 250 yr resolution). Because Norwegian Sea's bottom water temperature (BWT) is close to freezing, they expect little Glacial-Interglacial variation. Any significant down-core change would suggest additional control on Mg/Ca ratios in benthic foraminifera.

根据该奖项，PI将解决一个问题：方解石饱和对底栖有孔虫中Mg/ca温度关系的影响是什么？他们提议在挪威海上进行11天的巡游，以收集约30个多核和15个巨人覆盖恒温和盐度下一系列方解石饱和水平的重力核心。 底栖有孔虫Mg/ca的淡淡饱和水显示出急剧下降，随着水深的增加而急剧下降。当前的全局Mg/Ca-temprature关系只能解释降低的一部分，导致假设有组织饱和度也会影响深海典型的低温下底栖有孔虫mg/ca。先前由Mackensen等人（1985年）研究的均热和同类挪威海的深度横断面不仅提供了一个理想的机会，不仅可以检验假设，而且还可以量化低温下MG/CA-方解石饱和关系。 PI建议将用于Mackensen等人使用的位点重新占领。 1985 Faunal研究（）。基于这项研究，他们期望有足够的活底栖有孔虫。 为了进一步检验他们的假设，他们提出研究两个核心记录（一个跨越150年的HL-LGM过渡，一个记录在250年分辨率下跨越0至35 ka）。由于挪威海的底部水温（BWT）接近冰冻，因此他们预计几乎没有冰川间冰的变化。任何重大的下核变化都将表明底栖有孔虫中MG/CA比的额外控制。