Reconstructing the Glacial Thermocline at Little Bahama Bank

作为海洋环流的主要特征， 全球碳循环，温跃层的变化必须是 如果我们要了解这些过程， 第四纪气候波动。 初步结果，根据 1999年以来， 中温跃层和低温跃层在小巴哈马银行，建议 冰川温跃层约540米水深， 大约2摄氏度的冷却器和更多的13 c富集，它是 今天 该项目的目标是确定如何 营养物和物理特性的水深剖面图 在温跃层中的生物是从末次冰期 最大到目前为止。 目的是将温跃层 北大西洋亚热带环流到冰川的演变- 间冰期物理强迫因子的变化，全球 碳收支/大气pCO 2和中层/深水 流通 为了实现这一目标， 来自小巴哈马南侧沉积良好的岩芯 银行将收集超过深度范围400至1700米。 %%% 海洋环流的一个主要特征是 温跃层，温暖，混合良好的表面水位于顶部 更冷的深水。这个基本边界的深度必须 为了重建冰川时期 最后一次盛冰期的海洋历史。 这 该项目将利用海底的氧和碳同位素 在沉积岩芯中发现的有孔虫 小巴哈马银行记录的波动， 在气候波动期间的温跃层。演变 温跃层厚度温度和养分的模式 将首次在公海确定供应量 当地海岸的影响将缺席的环境。

As a primary feature of ocean circulation and key component of the global carbon cycle, changes in the thermocline must be accounted for if we are to understand the processes involved in Quaternary climatic fluctuation. Preliminary results, based on the benthic foraminiferal 018 and 13c records in cores from the mid-and lower-thermocline at Little Bahama Bank, suggest the glacial thermocline at about 540 meters wataer depth was approximately 2oC cooler and more 13c enriched that it is today. The objective for this project is to determine how bathymetric profiles of nutrients and physical properties within the thermocline have evolved from the last glacial maximum to the present. The goal is to relate thermocline evolution in the North Atlantic subtropical gyre to glacial- interglacial changes of physical forcing factors, the global carbon budget/atmospheric pCO2 and intermediate/deep water circulation. In order to accomplish this goal, a suite of cores from the well-sedimented southern flank of Little Bahama Bank will be collected Over the depth range 400 to 1700 meters. %%% A primary feature of ocean circulation is the depth of the thermocline where warm, well-mixed surface water lies on top of colder deep water. the depth to this fundamental boundary must be known for glacial periods in order to reconstruct the history of oceans during the last glacial maximum. This project will use oxygen and carbon iosotopes in benthic foraminifera found in sedimentary cores from the flanks of Little Bahama Bank to document the fluctuations of the thermocline during fluctuations of the climate. The evolution of patterns in theromcline thickness, temperature, and nutrient supply will be determined for the first time in an open ocean environment where local coastal effects will be absent.