Recent spatial and temporal variations in debris cover on Patagonian glaciers
Recent spatial and temporal variations in debris cover on Patagonian glaciers
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DOI：
10.1016/j.geomorph.2016.07.036
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发表时间：
2016-11
期刊：
影响因子：
3.9
通讯作者：
N. Glasser;T. Holt;Zachary D. Evans;B. Davies;M. Pelto;S. Harrison
中科院分区：
文献类型：
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作者：
N. Glasser;T. Holt;Zachary D. Evans;B. Davies;M. Pelto;S. Harrison
冰上碎片覆盖是冰川物质平衡的一个重要组成部分，特别是在冰川普遍衰退的地区。绘制了1987年至2015年期间南美洲南部温带北巴塔哥尼亚冰原退缩出口冰川表面碎片覆盖的时空变化图，显示碎片覆盖总量随着时间的推移而增加，从1987年的168万平方公里增加到2015年的307万平方公里。覆盖着碎片的冰川数量从1987年的24个增加到2001年的31个，2015年研究的43个冰川中有32个。碎片覆盖面积的比例也有所增加，从1987年的4.1%增加到2015年的7.9%，最大的比例增加发生在冰川分水岭以东(那里15.2%的冰川现在是碎片覆盖)。在这段时间里，NPI的总面积从4133平方公里减少到3887平方公里。冰川和冰缘湖泊占据的面积也从112平方公里增加到198平方公里。1987至2015年间，NPI的许多出口冰川的终端环境从陆地终止转变为湖泊崩解，这些冰川现在正在退缩为终端湖泊。被碎片覆盖的冰的面积的变化受到覆盖着碎片的终点站的冰的损失以及高海拔地区碎片覆盖率增加的影响。国家冰川研究所的冰川在退去时保持着高度的活力，因此表现出与高海拔冰川非常不同的表现，例如喜马拉雅冰川的冰川，那里的碎片覆盖导致终点处的冰川停滞。
Supraglacial debris cover is an important component of glacier mass balance, especially in areas characterised by widespread glacier recession. Mapping of the spatial and temporal changes in debris cover on the surface of the receding outlet glaciers of the temperate North Patagonian Icefield (NPI) in southern South America between 1987 and 2015 shows that the total amount of debris cover has increased over time, from 168 km2in 1987 to 307 km2in 2015. The number of debris-covered glaciers increased from 24 in 1987, to 31 in 2001 and 32 out of 43 studied glaciers in 2015. The proportion of debris-covered area has also increased, from 4.1% in 1987 to 7.9% in 2015, with the largest proportional increases occurring east of the ice divide (where 15.2% of the glacier ice is now debris covered). Over this time, the total area of the NPI decreased from 4133 to 3887 km2. The area occupied by proglacial and ice-proximal lakes also increased from 112 to 198 km2. Between 1987 and 2015, the terminal environment of many of the outlet glaciers of the NPI changed from land-terminating to lake-calving, and these glaciers are now receding into terminal lakes. The change in the area of debris-covered ice is influenced by the loss of ice at debris-covered termini and by an increase in debris cover at higher elevations. The glaciers of the NPI remain highly dynamic as they recede and are therefore behaving very differently to high-elevation glaciers, such as those of the Himalaya, where debris cover leads to glacier stagnation at the termini.