Jökull - 01.06.2000, Blaðsíða 39

Helgi Björnsson et al.
0 25 50
area d is tr ib u tion (km 2)
0
40 0
80 0
12 00
16 00
el
ev
at
io
n
(m
a
.s
.l.
)
0 25 0 500 75 0
cum u lative a rea (km 2)
0 10 20 30
vo lum e d is tr ibu tio n (km 3 )
0 50 100 15 0
cum u la tive vo lum e (km 3)
Figure 9. Distribution with elevation of ice surface, bedrock area and ice volume of Mýrdalsjökull. – Hæðar-
dreifing yfirborðs, botnflatar og ísrúmmáls Mýrdalsjökuls.
width of the ice drainage basin is 7-8 km in most parts
and the ice thickness reaches 740 m. Sólheimajök-
ull drains up to 500-600 m thick ice from a saddle
between Háabunga and Goðabunga that extends 1-
2 km inside the rim of the caldera. Sandfellsjökull
drains ice from the northeastern caldera rims and is
separated from Kötlujökull by Kötlukollar. Sléttjökull
and Botnjökull drain the northern flanks of the central
volcano. The ice catchment basin of one ice cauldron,
at the head of Sólheimajökull, about 2 km

in area, is
shown in Figure 10.
WATER DRAINAGE BASINS
Many rivers drain Mýrdalsjökull. The meltwater
reaches the glacier bed through moulins, crevasses
and veins, and drains along the base together with
basal meltwater produced by frictional and geo-
thermal heat. Subglacial drainage is commonly thoug-
ht to take place via numerous conduits that may join
together forming a few final tunnels, which leave the
glacier in a portal. Water that drains out of a number of
such portals joins in the foreland to one glacial river.
0 5 10 km
K ö tlu jö ku ll
S lé ttjöku ll, B o tn jö ku ll
Entu jöku ll
Só
lh
e i
m
a j
ök
u l
l
S a nd fe lls jö ku ll
Figure 10. Ice divides of the main ice drainage basins
of Mýrdalsjökull. – Skipting Mýrdalsjökuls í nokkur
helstu ísasvæði.
The watershed on the glacier for this river is drawn
as a continuation of the watershed outside the glacier
and encircles the individual water drainage basins on
38 JÖKULL No. 49