Collaborative Research: Surveying and drilling the submerged reefs of the western Indian Ocean-applications to sea level history, monsoon history, and radiocarbon calibration

水下珊瑚礁化石既是过去海平面变化的诊断指标，也是热带气候变化的无与伦比的档案。在热带的许多地区，潜礁序列是在最后一次消冰期的主要自然气候实验中沉积的。然而，到目前为止，对这些珊瑚礁的成功测量和采样只在少数几个地方实现。这笔奖金将装备一艘前往塞舌尔的游轮，目的是调查和钻探西印度洋可能在过去5万年沉积的水下珊瑚礁。巡航活动的目标有三个方面：(1)了解化石珊瑚礁的结构、年龄和范围——本质上是珊瑚礁对已知的最后一个冰河期周期海平面变化的反应(2)获取珊瑚样本，这些样本捕捉了在不同强迫时期的表面状态。(3)获得可进行配对放射性碳和U/Th定年的样品，从而可用于校准放射性碳时间尺度。涉及CHIRP地震剖面和疏浚的作业将在塞舌尔银行东侧进行。该地区以水下礁梯田的水深（和其他轶事）证据为特色。游轮将成为学生培训的理想平台，并将包括两名未被充分代表的少数民族学生。本项目由海洋科学部海洋地质与地球物理计划资助。

Chris Charles and Rick FairbanksSubmerged fossil coral reefs are both a diagnostic measure of past sea level change and an unparalleled archive of tropical climate change. In many regions of the tropics, the submerged reef sequences were deposited throughout the major natural climate experiment of the last deglaciation. However, thus far, successful surveying and sampling of these reefs has only been achieved in a few locations. This award will equip a cruise to the Seychelles for the purpose of surveying and drilling submerged reefs in the western Indian Ocean that were likely deposited over the last 50,000 years. The objectives of the cruise activities are three-fold: (1) To understand the structure, age, and extent of fossil reefs--in essence, the response of the reefs to the known sea level variations of the last ice age cycle (2) To acquire coral samples that captured the state of the surface during times of greatly different forcing. (3) To acquire samples that allow paired radiocarbon and U/Th dating and that therefore might be used to calibrate the radiocarbon time scale. The operations, involving CHIRP seismic profiling and dredging, will be conducted off the eastern flank of the Seychelles Bank. This region features bathymetric (and other anecdotal) evidence for submerged reef terraces. The cruise will serve as an ideal platform for student training and will include two underrepresented minority students. This project is supported by the Marine Geology & Geophysics Program of the Ocean Sciences Division.