Doctoral Dissertation Research: A Comparison of the Holocene Extents of the Greenland Ice Sheet in Western and Eastern Greenland

博士论文研究：格陵兰西部和东部格陵兰冰原全新世范围的比较

• 批准号: 1128909
• 负责人: Meredith Kelly
• 金额: $ 1.2万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1128909&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Comparison; Holocene

The Arctic is currently warming more rapidly than other locations on the planet and the response of the Greenland Ice Sheet to this warming is a focus of many current studies. Model projections of the contribution of the Greenland Ice Sheet to global sea level rise range from 4.5 to 17 cm by 2100. This project will help to understand the possible response of the Greenland Ice Sheet to future warming by developing records of the ice sheet margin during past warm times particularly during recent interglacial period (the Holocene Epoch, 11,650 years B.P. to present). The research will focus on the Kangerlussuaq region (67.0N, 50.7W) in western Greenland where a record of ice margin extents during the Holocene is marked by belts of prominent, well-preserved moraine ridges. Preliminary ages of moraines, determined by surface-exposure dating using the cosmogenic nuclide Beryllium-10, demonstrate the ability to date precisely the moraines near Kangerlussuaq. Results from one set of moraines, the ?Orkendalen moraines?, located just outboard of (and in some places adjacent to) the historical moraines, indicate that the Greenland Ice Sheet was smaller than at present between ~6,500 years ago and the historical advance culminating in A.D. 1850. The project will develop a chronology of the Greenland Ice Sheet margin fluctuations near Kangerlussuaq using a combination of detailed geomorphic mapping and surface-exposure dating of moraines. Ice sheet margin fluctuations will be compared with Holocene records of insolation, ocean circulation and surface air temperatures to examine the possible climate mechanisms that may have influenced the fluctuations of Holocene ice extent in eastern Greenland. The timing and spatial continuity of these fluctuations will provide insight into how the Greenland Ice Sheet will respond to future climate changes. This research will produce the first directly dated ice margin chronology in the Kangerlussuaq region in Greenland. Ice cores from the Greenland Ice Sheet register temperature, dustiness and other atmospheric conditions over the ice sheet, but do not provide information on how the sensitive margins of the ice sheet have changed. Combined with data from eastern Greenland, this new record from western Greenland will provide a geographically broad, spatial comparison of ice margin fluctuations that will be useful for testing hypotheses of climate mechanisms that cause ice sheet variability.As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

目前，北极的变暖比地球上的其他位置更快，格陵兰冰盖对这种变暖的反应是许多当前研究的重点。格陵兰冰块对全球海平面上升的贡献的模型预测范围从4.5厘米到2100厘米。该项目将有助于了解格陵兰冰块对未来对未来变暖的反应，这是通过在过去的温暖时期内开发冰盖边缘的记录，尤其是在最近的冰期期间（全新世纪，11,650年，B.P. 11,650年）。 这项研究将重点放在西部格陵兰西部的Kangerlussuaq地区（67.0n，50.7W），在全新世期间，冰缘量的记录都标志着突出，保存完好的冰ora山脊的带。通过使用宇宙核素铍-10来确定表面暴露日期确定的冰ora的初步年龄，证明了精确约会kangerlussuaq附近的冰rain虫的能力。 一套冰ora的结果是：位于历史莫拉纳人（在某些地方）的舷外（在某些地方），这表明，格陵兰冰盖比6500年前的格陵兰冰盖小于目前，历史前进的历史进步，最终在公元1850年在1850年达到最高限制。地图映射和表面曝光的冰for虫。 冰盖边缘的波动将与全新世的暴发，海洋循环和表面空气温度的记录进行比较，以检查可能影响东格陵兰东部全新世冰范围波动的气候机制。这些波动的时机和空间连续性将为格陵兰冰盖如何应对未来的气候变化提供深入的了解。 这项研究将在格陵兰的Kangerlussuaq地区产生第一个直接日期的冰缘年表。 格陵兰冰盖寄存器温度，尘土和其他大气条件的冰芯，但没有提供有关冰盖敏感边缘如何变化的信息。 结合来自格陵兰东部的数据，西部格陵兰西部的这一新记录将在地理上进行广泛的空间比较，对冰缘波动的波动进行比较，这将有助于测试导致冰纸变异性的气候机制的假设。作为博士学位论文研究改善奖，该奖项还将提供支持的支持学生来建立强大的独立研究职业。