Collaborative Research: Long Records of Paleoclimate from Florida

摘要ATM-9405145 Grimm，Eric C. 伊利诺伊州立博物馆名称：来自佛罗里达的古气候长记录 最近对北美东部连续50 000年的沉积物记录进行的研究表明，海因里希事件（从劳伦泰德冰盖流入北大西洋的冰流的大幅激增）与佛罗里达半岛植被的重大变化之间存在惊人的相关性。 这些事件表示在杜兰湖，佛罗里达，松树为主的社区和橡树为主的社区，这可能与潮湿的气候交替与极端干旱的时期的时间之间的突然转变。 这些结果表明，海因里希事件涉及海洋-大气环流的重要变化，从而迫使冰盖内部动力学以外的其他因素。 该奖项支持一个研究项目，该项目旨在实现以下目标：（1）建立杜兰湖沉积物的高分辨率AMS-放射性碳年代学。 该记录将验证佛罗里达的植被变化是否确实与海因里希事件同步;（2）重建杜兰湖的湖平面波动历史;（3）通过研究几个填充的天坑中新的长岩心（已经收集）的花粉地层学，扩展佛罗里达半岛植被和气候的区域和时间记录。 这些沉积物的时间跨度可能远远超过杜兰湖记录所涵盖的5万年，因此很有可能产生第一个跨越北美东部最后一个完整的冰期/间冰期循环的植被和气候变化记录。

Abstract ATM-9405145 Grimm, Eric C. Illinois State Museum Title: Long Records of Paleoclimate from Florida Recent research on a continuous 50,000-year sediment record from eastern North America has revealed a striking correlation between Heinrich events (large surges in flow of ice streams feeding from the Laurentide ice sheet into the North Atlantic) and major changes in vegetation in peninsular Florida. These events are expressed at Lake Tulane, Florida, as abrupt shifts between pine-dominated and oak-dominated communities, which likely correspond with times of moist climate alternating with periods of extreme drought. Those results suggest that the Heinrich events involved important changes in ocean-atmosphere circulation, and thus forcing other than internal dynamics of the ice sheet. This award supports a research project designed with the following objectives: (1) To establish a higher-resolution AMS-radiocarbon chronology for the sediments of Lake Tulane. The record will verify whether the vegetational shifts in Florida are indeed synchronous with Heinrich events; (2) To reconstruct the history of lake-level fluctuations in Lake Tulane; (3) To extend the regional and temporal records of vegetation and climate for peninsular Florida by studying the pollen stratigraphy of new long cores (already collected) from several in-filled sinkholes. These sediments appear likely to span much more than the 50,000 years covered by the Lake Tulane record, and thus have excellent potential to produce the first record of changes in vegetation and climate spanning the last complete glacial/interglacial cycle in eastern North America.