Seeking Hidden Glaciations of the Greenhouse World

寻找温室世界隐藏的冰川

• 批准号: 1155630
• 负责人: Howard Scher
• 金额: $ 28.5万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1155630&HistoricalAwards=false
• 关键词: Seeking; Hidden; Glaciations; Greenhouse; World; Seeking; Hidden; Glaciations; Greenhouse; World

The Eocene Epoch (56 to 34 million years ago) is generally thought of as a period of "greenhouse" climate conditions, but some evidence suggests that brief episodes of Antarctic glaciation may have occurred during this time. However, evidence for such glacial periods is indirect and up to now has not been firmly substantiated or characterized. This leaves significant gaps in our understanding of Eocene climate behavior, and of the processes associated with a period of profound change in Earth's history. The proposed work, led by a scientist from the University of South Carolina, will address this knowledge gap by using neodymium (Nd) and strontium (Sr) isotopic records to determine the timing, extent, and frequency of Eocene glacial events. Glacial weathering of Antarctic rocks produces detrital sediment with a unique isotopic signature, meaning that sediment produced on the Antarctic continent and deposited on the seafloor during glaciation is distinguishable within sediment cores. The project is motivated by preliminary Nd data that indicate a significant episode of Eocene glaciation ca. 37 million years ago, 3 million years earlier than previous estimates of the earliest Antarctic glaciation. To further identify and constrain glacial events in the middle to late Eocene, the proposed work will generate Nd and Sr records from Southern Ocean sediment cores collected by the Integrated Ocean Drilling Program (IODP).The datasets produced by this project will be relevant not only to understanding past Antarctic glaciation, but also to constraining low-latitude nutrient dynamics and productivity (for which glacial weathering is an important parameter). In this way, the proposed work aligns closely with the objectives of the Pacific Equatorial Age Transect (PEAT), a science program implemented by IODP. The project will involve an undergraduate and a graduate student. The project leader will also work with educators to develop Earth Science literacy programs for elementary school children.

始新世时期（56至3400万年前）通常被认为是“温室”气候条件的时期，但一些证据表明，在这段时间内可能发生了短暂的南极冰川发作。但是，这种冰川时期的证据是间接的，到目前为止尚未得到牢固证实或表征。这在我们对始新世气候行为的理解以及与地球历史发生深刻变化时期相关的过程中留下了很大的差距。 由南卡罗来纳大学的科学家领导的拟议工作将通过使用Neodymium（ND）和锶（SR）同位素记录来解决这一知识差距，以确定始新世冰川事件的时间，程度和频率。南极岩石的冰川风化可产生具有独特的同位素特征的有害沉积物，这意味着在南极大陆上产生的沉积物在冰川期间沉积在海底上的沉积物在沉积物核心内可区分。该项目是由初步的ND数据激励的，该数据表明始新世冰川的重要发作。 3700万年前，比先前对南极最早冰川的估计早300万年。为了进一步识别和限制始新世中间至晚期的冰川事件，提出的工作将产生ND和SR的记录，从综合海洋钻井计划（IODP）收集的南方海洋沉积物核心（IODP）中。该项目生产的数据集将不仅与理解过去的反熟食有关，还可以限制低层营养和生产力（也有生产力），而不是构成glac的生产力。这样，拟议的工作与IODP实施的科学计划太平洋赤道年龄率（PEAT）的目标紧密相吻合。该项目将涉及本科生和研究生。该项目负责人还将与教育工作者合作，为小学生开发地球科学素养计划。