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

克里斯·查尔斯和里克·费尔班克斯淹没的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，在末次冰消期的主要自然气候实验中，淹没的礁序列被沉积下来。然而，迄今为止，仅在少数几个地点成功地对这些珊瑚礁进行了调查和取样。该合同将装备一艘前往塞舌尔群岛的巡航船，以勘测和钻探西印度洋的暗礁，这些暗礁可能是在过去50 000年中沉积的。考察活动的目标有三个：⑴了解化石珊瑚礁的结构、年龄和范围-实质上是珊瑚礁对上一个冰河期周期已知海平面变化的反应; ⑵采集珊瑚样本，以反映在大不相同的作用力时期的表面状况。(3)获取允许配对放射性碳和U/Th测年的样品，因此可能用于校准放射性碳时间尺度。这些行动涉及CHIRP地震剖面和疏浚，将在塞舌尔浅滩东侧进行。这一地区的特点水深（和其他轶事）的证据淹没礁阶地。该邮轮将作为学生培训的理想平台，并将包括两个代表性不足的少数民族学生。该项目得到海洋科学司海洋地质地球物理方案的支助。

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.