Jökull - 01.01.2009, Side 2

Guðmundsson et al.
Figure 1. Locations of auto-
matic weather stations (AWSs)
at Hagafellsjökull outlet glacier
(G500: 500 m a. s. l.; and G1100:
1100 m a. s. l.), at Söðulhólar
(S300: 300 m a. s. l.) and north
of Skjaldbreiður (S475: 475 m
a. s. l.). Black dots in (a) and
(b): locations of mass balance
stakes. Langjökull (L), Hofsjök-
ull (H) and Vatnajökull (V) ice
caps are shown on the inset map
of Iceland and the configuration
of the equipment on the inset map
of an AWS. (b): Cross-section of
the profile in (a). – Staðsetning
sjálfvirkra veðurstöðva og mæli-
stika á Langjökli. Innsetta mynd-
in sýnir uppsetningu mælitækja.
level, and average around 900 m. The average altitude
of the equilibrium line is about 1100 m at the southern
outlets and 1200 m at the northern ones. Two major
rivers drain from the ice cap, Hvítá in Borgarfjörður
and Hvítá in Árnessýsla, although a significant part of
the glacial meltwater drains directly into groundwater
reservoirs (Sigurðsson, 1990).
Measurements of summer and winter balance
have been conducted annually at 23 locations on
Langjökull since 1996, supplemented by glacio-
meteorological observations that were initiated in
2001. Each year in April-May, cores for measur-
ing snow density have been drilled through the win-
ter layer. The summer balance has been measured in
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