Collaborative research: Unraveling the post-Pliocene Arctic Ocean transition to the icehouse climate

合作研究：揭示上新世后北冰洋向冰室气候的过渡

• 批准号: 1003732
• 负责人: Joseph Ortiz
• 金额: $ 8.91万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1003732&HistoricalAwards=false
• 关键词: Collaborative; research; Unraveling; post; Pliocene

Funds are provided to allow the PIs to develop a continuous record of changes in the Arctic Ocean in response to climatic cooling and growth of ice sheets in the Early to Middle Pleistocene based on sediment cores from the western Arctic Ocean. They will utilize a suite of proxies (microfaunal assemblages, stable and radiogenic isotopes, biomarkers, sediment mineralogy and elemental composition and grain size) to reconstruct variations in glacial inputs, sea ice, and water circulation. The use of paleobiological and geochemical proxies will be greatly enhanced by a unique sediment core that has a rich calcareous microfossil record extending through most of the Quaternary and potentially into the Pliocene, unlike other cores from the Arctic Ocean. This is a unique find that they can capitalize on as Arctic cores typically preserve calcareous microfossils only in Late Quaternary sediments. Age control will be achieved by paleomagnetic, 10Be, Sr-isotope, and cyclostratigraphic methods. This research will allow them to test whether there was an overall progressive growth in ice sheets and sea-ice cover and if sea ice and continental glaciers changed synchronously. They will also test whether the Mid Pleistocene Transition led to the growth of a super-thick Laurentide Ice Sheet by analyzing changes in glacial inputs from the northern Laurentide margin, with a multi-century scale record for the threshold glaciation ca. 650 ka, which initiated the icehouse world.

已提供资金，使研究所能够根据北冰洋西部的沉积物岩心，连续记录北冰洋在早更新世至中更新世期间因气候变冷和冰盖生长而发生的变化。他们将利用一套代用指标（微型动物组合、稳定同位素和放射性同位素、生物标志物、沉积物矿物学和元素组成及粒度）来重建冰川输入、海冰和水循环的变化。一个独特的沉积物岩心具有丰富的钙质微体化石记录，贯穿第四纪的大部分时间，并可能进入上新世，这将大大增强古生物学和地球化学代用指标的使用，这与北冰洋的其他岩心不同。这是一个独特的发现，他们可以利用北极核心通常只在晚第四纪沉积物中保存钙质微体化石。年龄控制将通过古地磁，10 Be，Sr同位素和旋回地层学方法来实现。这项研究将使他们能够测试冰盖和海冰覆盖是否有整体的渐进增长，以及海冰和大陆冰川是否同步变化。他们还将通过分析来自北方劳伦泰德边缘的冰川输入变化来测试中更新世过渡是否导致了超厚劳伦泰德冰盖的增长，其中有一个多世纪的阈值冰川记录。650 ka，开启了冰库世界。