Jökull - 01.01.2016, Page 65

The marginal zone of Tungnaárjökull, Iceland
Figure 10. Reconstruction of range changes in Tungnaárjökull’s snout and ice-dammed lake since the end of the
Little Ice Age (Andrzejewski et al., 2005, modified). A: Probable reach of the glacier and the proglacial lake at
the end of the LIA. B: Reconstruction of the extent of the glacier and the ice-dammed lake in the phase of the
delta development associated with the glacier’s advance ca. 1945. C: The present-day state on the basis of aerial
photographs of 2002. – Endurgerð af stærð Tungnaárjökuls ásamt þróun jökullóna og landslags frá lokum litlu
ísaldar til ársins 2002.
(Figure 10A). Except for the fragment of eroded end
moraine at approximately 840 m a.s.l. (Figure 10C)
there are no glacial landforms in the bottom of the
lake. The end moraine corresponds with the proximal
parts of the deltas and indicates the reach of the glacier
snout during the 1945 surge.
The basic changes in water level in the ice-
dammed lake were probably associated with the
damming and release of its drainage to the south-west
(Figure 10B). These changes were less affected by the
scale of glacial ablation.
Deposition of the kame terrace sediment most
likely took place during the recession of the glacier
after having crossed Jökulgrindur during the LIA. The
crossing is attested by marginal landforms situated on
the western side of the ridge (Figure 6). But we cannot
rule out the development of the terrace during the later
advances of the glacier (Evans et al., 2009). There is
no doubt, however, that in this area there was a par-
tial obstruction of meltwater flow between the glacier
and Jökulgrindur and the formation of a local through-
flow ice-dammed lake (Figure 11A). Small ice-bergs
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