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

大堡礁（GBR）钻探项目（IODP Exp. 325）旨在补充巴巴多斯和塔希提岛现有的冰川消融记录，并建立冰川消融期间和早期阶段的海平面和气候变化历史，以及珊瑚礁？美国对这些变化的反应。第325次考察队发现了225米长的珊瑚礁化石序列，其中许多代表了浅层珊瑚礁环境，涵盖了过去3万年甚至更久的海平面历史。IODP第325次科考的科学目标是：1)确定GBR冰川后海平面上升的过程；2)确定该地区在冰期/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，以及科学党的圆满实现？根据IODP义务，要求为每个回收的岩心建立准确而详细的年表。这些样品将通过u系列地质年代学测定年代，这是目前最准确、最精确的方法之一。在此，我们请求资金支持u系列珊瑚测年，以完成IODP第325次考察的研究目标。最近~3万年的海平面史，包括末次盛冰期（last Glacial Maximum， LGM）的最低海平面和消冰期的记录，是地球和海洋历史的重要组成部分。这一记录为海平面上升的速度提供了限制，这是预测未来海平面上升的关键。此外，根据卫星和潮汐计数据对当前海平面上升速度的估计需要进行校正，以便根据以前冰盖的存在对全球进行持续的均衡调整。这些修正依赖于过去3万年来海平面和冰盖的准确记录，这些记录来自几个间隔很广的地点。巴巴多斯和塔希提岛现有的冰川消融记录的广泛科学影响直接说明了拟议工作的知识价值和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消冰记录，填补这些记录在LGM和早期消冰期间的空白。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率是一个紧迫的科学和社会问题，准确的海平面历史将提供关于过去海平面与气候之间联系的关键信息。该项目的成果将通过演讲、出版物和与已成立的PAGES/IMAGES海平面工作组（PALSEA）的持续互动，以及与媒体的合作和交流，以及为普通观众改编的公开演讲，广泛传播。该项目包括博士后研究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。将积极鼓励代表性不足的群体参与。

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.