Subglacial bedform geomorphology of the Irish Ice Sheet reveals major configuration changes during growth and decay
Subglacial bedform geomorphology of the Irish Ice Sheet reveals major configuration changes during growth and decay
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爱尔兰冰盖的冰下床形地貌揭示了生长和衰退过程中的主要构造变化
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
R. Meehan
中科院分区：
文献类型：
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作者：
C. Clark;R. Meehan
罗根冰碛是爱尔兰地貌不可分割的一部分，这一迟来的认识，以及之前鼓林测绘的零碎方法，可能是爱尔兰冰盖古水流模式的高度对比视图的原因。使用高分辨率 (25 m) 数字高程模型，我们展示了爱尔兰中北部所谓的“Drumlin Belt”大部分区域（100 × 100 km）的形态图。这些地貌主要由比其他地方大得多的肋状冰碛组成（长达 16 公里），并且在某些地方相互叠加。与大多数先前的评估相反，我们发现河床形态记录包含许多重叠的河床形成事件（肋状冰碛、鼓状和岩尾），它们提供了变化的流动几何形状的重写记录。这些表明冰盖的质心和流动几何形状在生长和衰变过程中发生了变化。
The belated realisation that ribbed (Rogen) moraines form such an integral part of Irish geomorphology, and the piecemeal approach to previous drumlin mapping, is probably responsible for the highly contrasting views of palaeoflow patterns of the Irish Ice Sheet. Using a high resolution (25 m) digital elevation model we present morphological maps of a large part (100 × 100 km) of the so‐called ‘Drumlin Belt’ of north central Ireland. The landforms comprise mostly ribbed moraine much larger than found elsewhere (up to 16 km in length), which in places are superimposed on each other. Contrary to most prior assessments we find the bedform record to contain numerous and overlapping episodes of bed formation (ribbed moraine, drumlins and crag‐and‐tails) that provide a palimpsest record of changing flow geometries. These demonstrate an ice sheet with a centre of mass and flow geometry that changed during growth and decay.