Diatoms and Cosmogenic Isotopes as Tracers of West Antarctic Ice Sheet History and Processes

硅藻和宇宙成因同位素作为西南极冰盖历史和过程的示踪剂

• 批准号: 9980364
• 负责人: Reed Scherer
• 金额: $ 17.7万
• 依托单位: Northern Illinois University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-15 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9980364&HistoricalAwards=false
• 关键词: Diatoms; Cosmogenic; Isotopes; Tracers; West

9980364SchererThis award provides support for three years for analysis of sediments from beneath current and past grounded ice of the West Antarctic ice sheet. Diatoms and 10Be will be used not only for evidence of past deglacial conditions, but also as sedimentary tracers of microstratigraphic variability in piston cores recovered by Caltech glaciologists from beneath ice streams B, C and D, and inter-stream ridges. Similar analyses will be performed on sediment cores recovered from beneath the southern Ross Ice Shelf, and the southern Ross Sea near the ice front. Diatoms make excellent sedimentary tracers because, unlike most sedimentary particles, they have known initial conditions (original size, shape, approximate age, and environment of origin). The current study includes quantitative analysis of comminution of Ross Sea diatoms, from laboratory studies, using the ring-shear device developed by Iverson et al. (1998). Preliminary analyses suggest distinctive patterns of diatom breakage that could lead to guidelines for estimating load and shearing of marine diamictons, which may have important implications for interpreting past ice sheet configurations.

9980364谢勒该奖项为分析西南极冰盖当前和过去的地面冰下的沉积物提供了三年的支持。硅藻和10Be不仅将被用来证明过去的去冰川条件，而且还将被用来作为沉积示踪剂，在加州理工学院冰川学者从冰流B、C和D以及溪间海脊下找到的活塞芯的微地层变异性。类似的分析将对从南部罗斯冰架和靠近冰锋的南部罗斯海下面回收的沉积物岩芯进行。硅藻是很好的沉积示踪剂，因为与大多数沉积颗粒不同，它们具有已知的初始条件(原始大小、形状、大约年龄和起源环境)。目前的研究包括对罗斯海硅藻粉碎的定量分析，来自实验室研究，使用Iverson等人开发的环剪切装置。(1998年)。初步分析表明，硅藻破裂的独特模式可能导致估计海洋直径的负荷和剪切的指导方针，这可能对解释过去的冰盖配置具有重要意义。