Collaborative Research: Long Records of Paleoclimate from Florida

合作研究：佛罗里达州古气候的长期记录

• 批准号: 9405145
• 负责人: Eric Grimm
• 金额: $ 15万
• 依托单位: Illinois State Museum Society
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-15 至 1997-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9405145&HistoricalAwards=false
• 关键词: Collaborative; Research; Long; Records; Paleoclimate

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.

摘要ATM-9405145格林，埃里克·C·伊利诺伊州立博物馆标题：佛罗里达古气候的长期记录最近对北美东部连续50000年的沉积物记录进行的研究揭示了海因里希事件(从劳伦蒂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的显著相关性。这些事件在佛罗里达州的杜兰湖表现为以松树为主和以橡树为主的群落之间的突然转变，这可能与潮湿气候和极端干旱交替发生的时期相对应。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。该奖项支持一项旨在实现以下目标的研究项目：(1)为杜兰湖沉积物建立更高分辨率的AMS-放射性碳年代学。该记录将证实佛罗里达州的植被变化是否确实与海因里希事件同步；(2)重建杜兰湖湖面波动的历史；(3)通过研究从几个填充的天坑中收集的新的长岩芯的花粉地层学，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似乎远远超过杜兰湖记录所涵盖的5万年，因此极有可能产生北美东部最后一个完整的冰川/间冰期周期内植被和气候变化的第一个记录。