Expedition Objective Research: U-series Geochronology for IODP Expedition 325

探险目标研究：IODP 325 号探险的 U 系列地质年代学

• 批准号: 1129717
• 负责人: William Thompson
• 金额: $ 25万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129717&HistoricalAwards=false
• 关键词: Expedition; Objective; Research; series; Geochronology

The Great Barrier Reef (GBR) drilling project (IODP Exp. 325) was designed to complement existing deglacial records from Barbados and Tahiti, and to establish the history of sea level and climate change during deglaciation and earlier stages, and the reef?s responses to these changes. Expedition 325 recovered 225 m of fossil coral reef sequences, many representing shallow reef environments, encompassing the sea level history of the last 30,000 years, and beyond. The scientific objectives of IODP Expedition 325 are to: 1) Establish the course of postglacial sea level rise at the GBR; 2) Define SST variations for the region during the glacial/interglacial transition; 3) Analyze the impact of sea level changes on reef growth and geometry. The successful accomplishment of these goals, and the fulfillment of the Science Party?s IODP obligations, requires that an accurate and detailed chronology be established for each of the recovered cores. These samples will be dated by U-series geochronology, one of the most accurate and precise methods available. Here we request funds to support U-series dating of corals to accomplish the research objectives of IODP Expedition 325. The sea level history of the last ~30,000 years, including the lowest sea levels of the Last Glacial Maximum (LGM) and the record of the deglaciation, is a crucial piece of earth and ocean history. This record provides constraints on how fast sea level can rise, which is key for making projections of future sea level rise. Furthermore, estimates of the current rate of sea level rise from satellite and tide gauge data require corrections for the continuing isostatic adjustment of the globe from the presence of former ice sheets. These corrections depend on an accurate record of sea level and ice sheets over the last 30.000 years, from several widely spaced sites. The extensive scientific impact of the existing deglacial records from Barbados and Tahiti speak directly to the intellectual merit of the proposed work and the extremely high confidence for its successful outcome. The relative sea level record from the GBR will complement existing records of the deglaciation from Barbados and Tahiti, filling in gaps in those records during the LGM and early deglaciation. The GBR is an ideal location to refine models of glacial isostatic adjustment and identify sources of melt water. Estimating magnitudes and rates of future sea level change is an urgent scientific and societal problem and an accurate history of sea level will provide crucial information on past links between sea level and climate. The results of this project will be broadly disseminated through presentations, publications, and ongoing interactions with an established PAGES/IMAGES sea level working group (PALSEA), as well as cooperation and communication with the media, and public presentations adapted for a general audience. This project includes participation by a postdoctoral researcher and summer students to advance discovery and understanding while promoting teaching, training, and learning. The participation of underrepresented groups will be actively encouraged.

大堡礁钻探项目(IODP Exp.325)的目的是补充巴巴多斯和塔希提岛现有的冰川消融记录，并建立海平面和冰川消融和早期阶段气候变化的历史，以及珊瑚礁？S对这些变化的反应。探险325发现了225米长的珊瑚礁化石序列，其中许多代表了浅礁环境，涵盖了过去30,000年乃至更久的海平面历史。IODP考察队325的科学目标是：1)确定大洋洲冰后海平面上升的过程；2)确定该地区在冰川/间冰期过渡期间的海温变化；3)分析海平面变化对珊瑚礁生长和几何形状的影响。这些目标的成功实现和科学党S IODP义务的履行，需要为每一个回收的岩芯建立准确和详细的年表。这些样品将通过U系列地质年代学测定年龄，这是现有的最准确和最精确的方法之一。在此，我们请求资金支持珊瑚U系列测年，以实现IODP探险325的研究目标。近3万年来的海平面历史，包括末次冰盛期的最低海平面和冰川消融的记录，是地球和海洋历史中至关重要的一部分。这一记录限制了海平面上升的速度，这是预测未来海平面上升的关键。此外，根据卫星和验潮仪数据对目前海平面上升速度的估计需要根据以前冰盖的存在对地球持续的均衡调整进行修正。这些修正依赖于过去30.000年来几个相距较远的地点的海平面和冰盖的准确记录。巴巴多斯和塔希提岛现有冰川消融记录的广泛科学影响直接说明了拟议工作的学术价值以及对其成功结果的极高信心。GBR的相对海平面记录将补充巴巴多斯和塔希提岛现有的冰川消融记录，填补了末次盛冰期和早期冰川消融期间这些记录的空白。GBR是完善冰川均衡调整模型和确定融水来源的理想地点。估计未来海平面变化的幅度和速度是一个紧迫的科学和社会问题，准确的海平面历史将提供有关海平面与气候之间过去联系的重要信息。这一项目的成果将通过专题介绍、出版物、与已建立的海平面工作组(PALSEA)的持续互动以及与媒体的合作和交流，以及为广大观众改编的公开演示而广泛传播。该项目包括博士后研究人员和暑期学生的参与，以促进发现和理解，同时促进教学、培训和学习。将积极鼓励代表人数不足的群体参加。