Jökull - 01.01.2020, Síða 26

Glacier extent in Iceland, 1890–2019
Figure 11: The extent of the glaciers on Tröllaskagi and Flateyjarskagi is only shown in ∼1890 and 2019. Their outlines for
∼2000 has also been mapped but is not shown as it is close to the 2019 outlines. – Útlínur jökla á Trölla- og Flateyjarskaga
um 1890 og 2019. Útlínur þeirra frá árinu 2000 hafa einnig verið kortlagðar, en eru ekki sýndar hér vegna þess að þær
falla nánast saman við útlínurnar frá árinu 2019.
Variations in glacier area since the end of the 19th
century
The variation in the area of glaciers in Iceland since
the late 19th century shows that the larger ice caps
(Vatnajökull, Hofsjökull, Langjökull and Mýrdalsjök-
ull) have lost approximately 10–30% of their max-
imum LIA area, whereas intermediate-size glaciers
have lost 35–85%, in general, with larger relative area
loss the smaller the glacier (Figure 12). There is,
however, a larger error in the estimated maximum
LIA extent of the smaller glaciers, due to the scarcity
of moraines and other glacial geomorphological evi-
dence. Slight errors in the maximum LIA extent of the
smaller glaciers, considerably affect the relative area
curve for the whole time series.
The (absolute) area changes of the ice caps and
glaciers considered in this paper are shown in Figure
13. The surge of Brúarjökull in 1963–1964 is the only
surge that considerably affected the area of an entire
ice cap or glacier since the end of the 19th century.
During that surge, this outlet glacier increased in area
by 160 km2 due to the advance of the terminus (Guð-
mundsson et al., 1996).
Data on glacier area from additional sources have
been included in Figure 12 to increase the temporal
detail – these are derived from glacier outlines not
JÖKULL No. 70, 2020 23