of validation data.
COMPARISON WITH GLACIOLOGICAL DATA
The spatial variability of the mass balance on large ice masses, such as
Vatnajökull and Langjökull ice caps, can be mapped given data along several
profiles extending over the elevation range of the ice caps. Mass balance has
been observed on parts of Vatnajökull ice cap in SE-Iceland since 1991 (Björns-
son et al., 1998) and from 1996
/media/ces/Paper-Olafur-Rognvaldsson_91.pdf
rapidly to changes in temperature and pre-
cipitation during historical times (Björnsson, 1979; Björns-
son et al., 2003; Björnsson and Pálsson, 2008; Guðmundsson
et al., 2011). The recorded volume and area changes of these
glaciers are therefore good indicators of climate change.
Historical records of the glacier extent reach back to the
settlement of Iceland in the late 9th century. During
/media/ces/Adalgeirsdottir-etal-tc-5-961-2011.pdf
coincide with jökulhlaups.
Monitoring Systems
To monitor seismic and volcanic activity in
Iceland, IMO operates a nationwide digital
network of 44 seismic stations (network name:
SIL) [Bödvarsson et al., 1999], six volumetric
borehole strain meters, and 16 continuous
GPS stations (network name: ISGPS) (H. Geirs-
son et al., Current plate movements across
the Mid-Atlantic Ridge determined
/media/jar/myndsafn/2005EO260001.pdf
m
J
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/media/ces/2010_017.pdf