Jökull - 01.01.2012, Síða 156

S. Brynjólfsson et al.
of the Svarfaðardalur valley (Figure 2). The surge-
type glaciers Búrfellsjökull (1.45 km2) and Teigar-
jökull (0.7 km2) descend from about 1200 m a.s.l. to
about 800 m a.s.l.
Historical surge activity
The surge history of glaciers on the Tröllaskagi
peninsula is interesting as only four surges have
been reported from three glaciers out of more than
150 glaciers on the peninsula (Hallgrímsson, 1972;
Björnsson, 1991; Björnsson et al., 2003). Apart from
the Teigarjökull and Búrfellsjökull glaciers, the third
known surging glacier, not discussed in this paper, is
called the Bægisárjökull glacier and had a recorded
surge in 1801 (Björnsson, 1971). A possible surge
event occurred in 1712 AD, when farmers in northern
Tröllaskagi peninsula observed large and rapid move-
ments of ice in a small cirque glacier in the Kálfs-
árdalur valley. The river coming from the glacier
rapidly became brownish in color and remained un-
usually loaded with sediments for a few years (Magn-
ússon and Vídalín, 1943). More surge events may
have occurred over the last few decades, as there are
sporadic reports of extremely crevassed glacier sur-
faces, extraordinary advances of glacier terminuses
between years and unusually steep glacier margins
(Escritt, 1974, 1978), but these observations have not
been verified as having been caused by surges. The
reason why only few surges have been reported from
an area hosting more than 150 glaciers could be the
remote location of most of the glaciers, which could
make surges by small cirque glaciers go unnoticed,
or, alternatively, that surge-type glaciers are rare in
the area.
Figure 2. The surge-type cirque glaciers Teigarjökull (left) and Búrfellsjökull (right), seen towards south, 1st
of July 2007. – Framhlaupsjöklarnir Teigarjökull (til vinstri) og Búrfellsjökull (til hægri) séðir af fjöllunum
norðan í framdal Svarfaðardals 1. júlí 2007.
154 JÖKULL No. 62, 2012