High-Resolution Constraints on the Magnitude and Timing of Climate Change in Iceland Over the Past 15 ka.

这是科罗拉多大学和冰岛大学的首席研究人员共同提出的建议。冰岛位于热带来源的极地冷气团和相对温暖的气团之间，以及相对新鲜的东格陵兰岛流和温暖、咸的北大西洋漂流之间。大气或海洋环流的细微变化可能导致了陆地环境的强烈变化。因此，北大西洋全新世环流变化对冰岛的影响可能比大多数其他北大西洋大陆更大。冰岛自定居以来一直有环境变化的历史记录，观察到的巨大变化证实了冰岛对气候的敏感性。该项目的目标是通过目前的间冰期重建冰岛的大冰盖，并记录在冰川消融期间发生的突变，以及陆地环境变化的规模、时间和可能的周期性。首席调查人员将尝试回答两个具体问题：1)一些现存的大冰盖是否在全新世早期消失，如果是，它们何时重新生长；2)冰川消融期间陆地和近岸的环境条件是什么？将从两个深的、高沉积速率的湖盆中回收连续的岩芯。之所以选择这些湖泊，是因为这些沉积物有望提供过去一万到一万五千年来环境变化的高分辨率、定量证据。首席调查员将采用多重代理方法，重点研究沉积物的物理特征、湖泊初级生产力的变化、孢粉学和海洋微古生物学。这些数据应该使他们能够确定冰岛全新世环境变化是否存在自然周期性，类似于从邻近海洋和格陵兰冰盖报告的情况。

Miller0138010This is a collaborative proposal among Principal Investigators at the Universities of Colorado and Iceland. Iceland is situated at the boundary between cold, polar air masses and relatively warm air masses of tropical origin and between the cold, relatively fresh East Greenland Current and the warm, salty North Atlantic Drift. Subtle shifts in either atmospheric or oceanic circulation may have produced strong changes in the terrestrial environment. Therefore, the impact of North Atlantic Holocene circulation variability was likely to be stronger on Iceland than most other North Atlantic landmasses. There has been a historical record of environmental change on Iceland since its settlement and the large variations observed confirm Iceland's climate sensitivity. The goal of the project is to reconstruct Iceland's large ice caps through the present interglacial and document abrupt shifts that occurred during deglaciation, and the magnitude, timing and possible cyclicity of terrestrial environmental change. The Principal Investigators will attempt to answer two specific questions: 1) did some of the extant large ice caps disappear in the early Holocene, and if so, when did they regrow and 2) what were the terrestrial and near-shore environmental conditions during deglaciation? Continuous cores from two deep, high-sedimentation-rate lake basins will be recovered. These lakes were selected because the sediments are expected to provide high-resolution, quantitative evidence of environmental change over the past 10 to 15 thousand years. The Principal Investigators will undertake a multiproxy approach, with an emphasis on physical characteristics of the sediments, lacustrine primary productivity changes, palynology, and marine micropaleontology. These data should allow them to determine whether there is a natural cyclicity in Holocene environmental change on Iceland, similar to that reported from the adjacent oceans and the Greenland Ice Sheet.