Cryosphere and East Asian monsoon variability during the latest Miocene (7-5 Ma)

在新第三纪，地球慢慢地从温室转变为冰室，最终在北方高纬度地区形成了广泛的更新世冰盖。相对温暖的晚中新世时期可能为了解未来气候发展提供了一个密切的类比。我们建议开发一个晚中新世（7-5马）天文校准的底栖同位素地层学在沉积拼接构造富碳酸盐序列钻探在ODP网站1146在中国南海。将在相同的样品中测量高分辨率的南极稳定同位素，以对比亚热带西太平洋表层和底层水团的时间演变，并评估墨西拿“盐度危机”（5.96 - 5.33 Ma）对东南亚季风的潜在影响。我们的同位素记录还将提供有关地球历史上温暖时期气候变化的速度和幅度以及主要强迫机制的重要信息。我们的工作将与ODP Site 1146公布的同位素数据相结合，以生成过去1600万年的方法学一致的年代参考。在一个单一的核心中分析这种连续和连贯的气候档案将提供对北方和南半球冰盖的发展、副热带季风气候和大洋间环流的重大重组的限制，从而将有助于我们对气候-海洋动力学的理解。

During the Neogene, Earth slowly transitioned from Greenhouse to Icehouse conditions, culminating with development of extensive Pleistocene ice sheets over the northern high latitudes. The relatively warm late Miocene period potentially offers a close analogue to understand future climate developement. We propose to develop a late Miocene (7-5 Ma) astronomically-calibrated benthic isotope stratigraphy in a sedimentary splice constructed from carbonate-rich successions drilled at ODP Site 1146 in the South China Sea. High-resolution planktic stable isotopes will be measured in the same samples to contrast the temporal evolution of surface and bottom water masses in the subtropical West Pacific and to evaluate potential repercussions of the Messinian „salinity crisis“ (5.96 – 5.33 Ma) on the Southeast Asian monsoon. Our isotopic records will also provide important information about the pace and magnitude of climate change and main forcing mechanisms during a warmer interval of Earth’s history. Our work will be integrated with published isotope data from ODP Site 1146 to generate a methodology-consistent chronological reference for the last 16 million years. Analysis of this continuous and coherent climate archive in a single core will provide constraints on the development of Northern and Southern Hemisphere ice sheets, subtropical monsoonal climate and major re-organizations in inter-ocean circulation, and will thus contribute to our understanding of climate-ocean dynamics.