• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nature >Delta progradation in Greenland driven by increasing glacial mass loss
【24h】

Delta progradation in Greenland driven by increasing glacial mass loss

机译：冰川质量损失增加导致格陵兰三角洲升级

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska(2), Siberia(3) and western Canada(4), and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.
机译：北极地区气候变化明显，并增加了北极沿海地区的脆弱性（1）。例如，格陵兰冰原的融化增加以及海冰和永冻土分布的减少可能会改变沿海的地貌动力学。格陵兰岛的三角洲在很大程度上不受人类活动的影响，但是增加的淡水径流和泥沙通量可能会增加三角洲的大小，而无冰期波浪活动的增加可能会减小三角洲的大小，目前尚不清楚其净影响。在这里，我们表明，格陵兰西南部的三角洲在1940年代至1980年代基本上是稳定的，但在1980年代至2010年代的北极变暖中却逐渐发展（即沉积物将三角洲延伸到海中）。我们的结果基于自1940年代以来121个三角洲的面积变化，并使用新发现的航空照片和遥感影像进行了评估。我们发现，三角洲的增长是由格陵兰冰原的高淡水径流与开阔水位相伴而生的。退化的控制取决于当地的初始环境条件（即，1980年代每年累积的空气温度高于0摄氏度，淡水径流和海冰），而不是各个三角洲的1980年代至2010年代这些条件的局部变化。这与阿拉斯加（2），西伯利亚（3）和加拿大西部（4）沿海平原沿北极沉积海岸的主要侵蚀趋势形成鲜明对比，并且与大三角洲沿岸侵蚀和增生的空间变化格局形成鲜明对比。北极的主要河流5-7。我们的结果增进了人们对气候变化中北极沿海演变的理解，并揭示了冰量损失增加以及相关的淡水径流和开放水期延长对沿海地区的影响。

著录项

  • 来源
    《Nature》 |2017年第7674期|101-104|共4页
  • 作者

    Bendixen Mette; Iversen Lars Lonsmann; Bjork Anders Anker; Elberling Bo; Westergaard-Nielsen Andreas; Overeem Irina; Barnhart Katy R.; Khan Shfaqat Abbas; Box Jason E.; Abermann Jakob; Langley Kirsty; Kroon Aart;

  • 作者单位

    Univ Copenhagen, Ctr Permafrost CENPERM, DK-1350 Copenhagen, Denmark;

    Univ Copenhagen, Dept Biol, Freshwater Biol, DK-2100 Copenhagen, Denmark;

    Univ Copenhagen, Ctr GeoGenet, Nat Hist Museum Denmark, DK-1350 Copenhagen, Denmark|Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA|NASA, Jet Prop Lab, Pasadena, CA 91109 USA;

    Univ Copenhagen, Ctr Permafrost CENPERM, DK-1350 Copenhagen, Denmark;

    Univ Copenhagen, Ctr Permafrost CENPERM, DK-1350 Copenhagen, Denmark;

    Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA;

    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA|Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA;

    Tech Univ Denmark, DTU Space, Natl Space Inst, DK-2800 Lyngby, Denmark;

    Geol Survey Denmark & Greenland GEUS, DK-1350 Copenhagen, Denmark;

    Asiaq Greenland Survey, Postbox 1003, Nuuk 3900, Greenland;

    Asiaq Greenland Survey, Postbox 1003, Nuuk 3900, Greenland;

    Univ Copenhagen, Ctr Permafrost CENPERM, DK-1350 Copenhagen, Denmark;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号