Drumlins form at the ice/bed interface through subglacial processes that are not directly observable. The internal stratigraphy of drumlins provides insight into how they developed and associated subglacial processes, but traditional stratigraphic logging techniques are limited to natural exposures and excavations. Using ground-penetrating radar, we imaged the internal stratigraphy of seven drumlins from a recently exposed drumlin field in the forefield of Múlajökull, Iceland. Data were collected with 100 and 200 MHz antennas with maximum resolvable depths of 8 and 4 m, respectively. Longitudinal echograms contained coherent down-ice dipping reflectors over the lengths of the drumlins. Near the drumlin heads (i.e., stoss sides), down-glacier dipping beds lie at high angles to the surface, whereas on the lee sides, the down-glacier dipping beds lie at low angles, or conform, to drumlin surfaces. Transverse echograms exhibited unconformities along the flanks of drumlin heads and conformable bedding across the lee side widths of the drumlins. These observations were ground-truthed with stratigraphic logs from a subset of drumlins and good agreement was found. The stratigraphic patterns support previous conclusions that drumlins at Múlajökull formed on a deformable bed through both depositional and erosional processes which may alternate between its surge and quiescent phases.

中文翻译：

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从冰岛穆拉冰川（Múlajökull）的探地雷达洞察鼓浪峰的发展，这是一个浪涌型冰川

Drumlins 通过无法直接观察到的冰下过程在冰/床界面形成。鼓林的内部地层学提供了他们如何发展和相关的冰下过程的洞察力，但传统的地层测井技术仅限于自然暴露和挖掘。使用探地雷达，我们对冰岛穆拉冰川前场最近暴露的鼓林场中的七个鼓楼的内部地层进行了成像。使用 100 和 200 MHz 天线收集数据，最大可分辨深度分别为 8 和 4 m。纵向回波图包含在鼓形长度上的相干冰下浸反射器。在鼓林头附近（即 stoss 侧），冰川下的浸渍床与地表成高角度，而在背风侧，冰川下的浸渍床以低角度或顺应鼓林表面。横向回声图显示出沿鼓轮头部侧面的不整合和跨鼓轮背风侧宽度的顺应层。这些观察结果与来自鼓林子集的地层测井数据一致，并且发现了良好的一致性。地层模式支持先前的结论，即 Múlajökull 的鼓林通过沉积和侵蚀过程在可变形的床上形成，沉积和侵蚀过程可能在其激增阶段和静止阶段之间交替。这些观察结果与来自鼓林子集的地层测井数据一致，并且发现了良好的一致性。地层模式支持先前的结论，即 Múlajökull 的鼓林通过沉积和侵蚀过程在可变形的床上形成，沉积和侵蚀过程可能在其激增阶段和静止阶段之间交替。这些观察结果与来自鼓林子集的地层测井数据一致，并且发现了良好的一致性。地层模式支持先前的结论，即 Múlajökull 的鼓林通过沉积和侵蚀过程在可变形的床上形成，沉积和侵蚀过程可能在其激增阶段和静止阶段之间交替。