The age of surface-exposed ice along the northern margin of the Greenland Ice Sheet
The age of surface-exposed ice along the northern margin of the Greenland Ice Sheet
复制标题
格陵兰冰盖北缘地表暴露冰的年龄
DOI：
10.1017/jog.2020.62
复制
发表时间：
2020
影响因子：
3.4
通讯作者：
J. Welker
中科院分区：
文献类型：
--
作者：
J. MacGregor;M. Fahnestock;W. Colgan;N. K. Larsen;K. Kjeldsen;J. Welker
摘要每年夏天，格陵兰冰盖边缘的表面融化暴露出一个独特的可见地层，这与过去的变化在陆上尘埃沉积在整个积累区和随后的冰流向边缘。在这里，我们使用2019年融化季节结束时镶嵌的Sentinel-2多光谱卫星图像和更高分辨率的WorldView-2/3图像，沿着北方边缘绘制了冰盖沿着的表面地层。我们跟踪三个明显的尘埃浓度和一个较暗的基底层的顶部不同的过渡。这三次尘埃转变之前已被确定为代表晚更新世气候转变，使我们能够为北方格陵兰岛制定粗略的年代地层学。晚更新世地层的大量褶皱被观察到，但并不常见。格陵兰岛北方最古老的共形地表露冰可能位于暖地附近，可能长达5.5万年。底冰通常暴露在距冰缘数百米的地方，可能表明广泛的冻结的基底热状态。我们的结论是，整个北方格陵兰岛的冰缘提供了多种机会，恢复古气候不同的冰相对于以前研究的地区在格陵兰岛西南部。
Abstract Each summer, surface melting of the margin of the Greenland Ice Sheet exposes a distinctive visible stratigraphy that is related to past variability in subaerial dust deposition across the accumulation zone and subsequent ice flow toward the margin. Here we map this surface stratigraphy along the northern margin of the ice sheet using mosaicked Sentinel-2 multispectral satellite imagery from the end of the 2019 melt season and finer-resolution WorldView-2/3 imagery for smaller regions of interest. We trace three distinct transitions in apparent dust concentration and the top of a darker basal layer. The three dust transitions have been identified previously as representing late-Pleistocene climatic transitions, allowing us to develop a coarse margin chronostratigraphy for northern Greenland. Substantial folding of late-Pleistocene stratigraphy is observed but uncommon. The oldest conformal surface-exposed ice in northern Greenland is likely located adjacent to Warming Land and may be up to ~55 thousand years old. Basal ice is commonly exposed hundreds of metres from the ice margin and may indicate a widespread frozen basal thermal state. We conclude that the ice margin across northern Greenland offers multiple opportunities to recover paleoclimatically distinct ice relative to previously studied regions in southwestern Greenland.
登录
查看更多内容
影响因子：
5.2
作者：
Kate Winter;John Woodward;S. Dunning;C. Turney;C. Fogwill;A. Hein;N. Golledge;R. Bingham;S. Marrero;D. Sugden;N. Ross
通讯作者：
Kate Winter;John Woodward;S. Dunning;C. Turney;C. Fogwill;A. Hein;N. Golledge;R. Bingham;S. Marrero;D. Sugden;N. Ross
影响因子：
64.8
作者：
Yuzhen Yan;M. Bender;E. Brook;H. Clifford;P. Kemeny;A. Kurbatov;Sean L. Mackay;P. Mayewski;J. Ng;J. Severinghaus;J. Higgins
通讯作者：
Yuzhen Yan;M. Bender;E. Brook;H. Clifford;P. Kemeny;A. Kurbatov;Sean L. Mackay;P. Mayewski;J. Ng;J. Severinghaus;J. Higgins
海冰与风暴：是什么控制着北极冰芯中的海盐？
影响因子：
5.2
作者：
Rhodes R
通讯作者：
Rhodes R
前所未有的大气条件（1948
DOI：
10.5194/tc-14-1209-2020
发表时间：
2020
期刊：
The Cryosphere
影响因子：
--
作者：
Tedesco, Marco;Fettweis, Xavier
通讯作者：
Fettweis, Xavier