Dataset for 'Influence of glaciological structures on the spatial distribution of cryoconite holes, northern Victoria Land, East Antarctica'

Three blue-ice areas in the upper reaches of Rennick Glacier, East Antarctica, are investigated using satellite remote sensing to assess the influence of meso- to large-scale glaciological structures on cryoconite hole distribution. In total, 15 299 cryoconite holes and 1 600 structures are geospatially analysed, which indicate cryoconite holes are commonly concentrated in areas with prominent meso-scale ice structures. The emergence of debris entrained in primary stratification promotes the development of cryoconite holes along the surface expression of debris-bearing layers. Differential ablation of penetrative structures and their constituent ice facies can form a ridge-and-furrow ice-surface topography that captures supraglacial hydrology and sediments. As a result, trains of cryoconite holes develop in furrows that trace the surface expression of planar layers. Large-scale topographic barriers that form at flow-unit boundaries constrain cryoconite holes within discrete flow units by inhibiting the transport of supraglacial sediments. The majority of cryoconite holes are located in low-slope areas (< 5°) where sediments are less susceptible to stripping events. Cryoconite holes on steeper slopes are preferentially located near to flow-unit boundaries where the topographic expression of meso-scale structures can offset the influence of larger-scale topography by preventing sediments being washed down-slope. Although a range of variables can influence the distribution of cryoconite holes, meso- to large-scale structures play an important role in the development of ice-surface topography and the delivery of sediments from different sources, which can strongly influence the distribution and composition of cryoconite holes.

本研究针对东南极洲伦尼克冰川上游的三处蓝冰区开展卫星遥感（satellite remote sensing）调查，以评估中至大型冰川构造对冰尘穴（cryoconite hole）分布的影响。研究共对15299个冰尘穴与1600处构造开展空间地理分析，结果表明冰尘穴通常富集于发育显著中尺度冰构造的区域。初始层理中夹带的碎屑出露后，会沿含碎屑层的地表露头处促进冰尘穴的发育。穿透性构造及其所含冰相的差异消融，可形成脊槽型冰面地形，该地形可截留冰面水文与沉积物。受此影响，沿平面层理地表露头分布的槽谷中会形成串状分布的冰尘穴。在流动单元边界形成的大型地形屏障，可通过抑制冰面沉积物的运移，将冰尘穴限制在离散的流动单元内。绝大多数冰尘穴分布于坡度小于5°的缓坡区域，此类区域内沉积物更不易发生剥离流失。陡坡区域的冰尘穴则优先分布于流动单元边界附近，此处中尺度构造的地形表达可通过阻止沉积物沿坡向下冲刷，抵消更大尺度地形的影响。尽管诸多变量均可影响冰尘穴的分布，但中至大型构造在冰面地形发育与不同来源沉积物的输送过程中发挥着关键作用，进而可显著调控冰尘穴的分布与组成。