Jökull - 01.01.2012, Blaðsíða 127

Glacier changes in the marginal zone of Sólheimajökull
Figure 10. Elevation change map 1996–2010. Positive values represent glacier thickening or deposition, and
negative values represent glacier thinning or erosion. – Kort af hæðarbreytingum frá 1996 til 2010. Jákvæð
gildi tákna þykknun jökulsins en neikvæð gildi þynningu eða rof.
can be interpreted as an ice thickness map for 1996.
The surface lowering due to glacier melting in the
zone between the 2004 and 2010 margins amounts to
120–150 m over this 14 year period. This gives an an-
nual lowering rate of 8.6–10.7 m in the snout area of
Sólheimajökull. Figure 10 also shows that the glacier
thinned 60–90 m in the area 2.5–4.5 km upglacier
from the 1996 margin. The general pattern identifies
increasing thinning in the lower part of the glacier.
The pattern of surface change in the forefield is also
picked up by Figure 10. The erosion in the main melt-
water channel is 5–20 m and 5–10 m at the western
flank of Jökulhaus. This is due to normal glacioflu-
vial erosion, the jökulhlaup in 1999, and removal of
sediments on unstable slopes. In a small area at the
northwestern ’corner’ of the 1996 margin, Figure 10
shows 5–15 m of surface increase. This most likely
represents debris deposited by the 1999 jökulhlaup.
Figure 11 shows the surface elevation change from
1960 to 2010. In 2010, the glacier margin was 409 m
further upglacier than in 1960 (Figure 2). The glacier
is overall 20–40 m thinner in 2010 than in 1960.
JÖKULL No. 62, 2012 125