Fláajökull (north lobe), Iceland: active temperate piedmont lobe glacial landsystem

A 1:6250 map of the foreland of Fláajökull's north lobe as it appeared in 1989, together with a 1:350 scale map of a sample area of recently exposed glacial landforms from 2014, enables an assessment of the spatial and temporal evolution of glacial landform assemblages at the margin of an active temperate piedmont lobe terminating at ice-marginal thickening till wedges. The pattern of landform development captured in these maps indicates that the glacier margin developed strong longitudinal crevassing and well-developed ice-marginal pecten (three-dimensional crenulations) during its historical recession. This is recorded by early recessional phase linear push moraines on well-drained distal slopes of the foreland and the later development of interrelated sawtooth moraines, crevasse squeeze ridges and till eskers, indicative of extending ice flow and poorly drained submarginal conditions. This landform record is a palaeoglaciological signature of a changing process–form regime inherent within the active temperate piedmont lobe landsystem model.

本数据集包含两幅冰川地貌相关地图：其一为1989年弗拉约库尔冰川（Fláajökull）北支冰舌冰前地带的1:6250比例尺地图，其二为2014年新近出露的冰川地貌样区的1:350比例尺地图，可用于评估终止于冰缘加厚冰碛楔的活动温性山麓冰舌边缘的冰川地貌组合时空演化规律。两幅地图所捕捉的地貌发育格局显示，该冰川边缘在历史退缩过程中形成了显著的纵向裂隙与发育完善的冰缘栉状构造（三维皱缩构造）。这一演化过程可通过冰前地带排水良好的远端斜坡上的早期退缩阶段线性推积冰碛垅，以及后续形成的相互关联的锯齿状冰碛垅、裂隙挤压脊与冰碛蛇形丘得到记录，上述地貌特征共同指示了冰流扩张与排水不畅的冰缘下环境。该地貌记录是活动温性山麓冰舌地貌系统模式中固有的变化过程-形态体系的古冰川学指征。