Jökull - 01.01.2019, Page 11

Guðmundsson et al.
Figure 6. The development of glacier-dammed lakes in side valleys at the margin of Skeiðarárjökull. For expla-
nations and credits see the caption of Figure 3. – Þróun jökulstíflaðra lóna í hliðardölum við jaðar Skeiðarár-
jökuls. Sjá nánari skýringar við 3. mynd.
Skaftafellsjökull
In 1904, the terminus of Skaftafellsjökull had started
to retreat from the LIA maximum extent in ∼1890
(DGS, 1905a). The retreat was up to 250–300 m mid-
way between Skaftafellsheiði and the point of con-
fluence between Skaftafellsjökull and Svínafellsjökull
(Figures 5 and 9) where a medial moraine extended
from Hafrafell to the LIA merged terminus.
The retreat in the early 20th century led to the for-
mation of terminus lakes, and aerial photographs from
1945 show six small lakes with a combined area of
0.15 km2 by the terminus, which had then retreated
by 1.1–1.25 km from the LIA maximum extent (Fig-
ures 5 and 9). They formed between the glacier and
a terminus moraine, that had been overridden by the
LIA advance of the glacier, from which the glacier
had retreated in the 1930s. These lakes, and a few
additional lakes that formed later in the 20th century,
disappeared or became isolated from the terminus and
are not part of the terminus lake in 2018. The ice mar-
gin more or less maintained a similar position from
the 1960s to the end of the century, when it started to
retreat rapidly. The total retreat since that time is 0.5–
1.5 km.
New terminus lakes started forming by Skafta-
fellsjökull in 2001 at the western part of the ice mar-
gin. Five lakes can be seen on a Landsat 7 image
from 2006. They grew rapidly and merged into a
single lake in 2011. This lake has reached the out-
ermost part of the deep subglacial trough under the
10 JÖKULL No. 69, 2019