Jökull - 01.01.2020, Page 25

Hannesdóttir et al.
Figure 10: The extent of Þrándarjökull and Hofsjökull eystri in East-Iceland at several times since ∼1890. – Útlínur
Þrándarjökuls og Hofsjökuls eystri á mismunandi tímum frá því um 1890.
The ∼1890 glacier outline presented here (Figure
11) is a first attempt to delineate the maximum LIA
extent for most of the glaciers on the peninsula. The
origin and formation of the glaciers is diverse, and
the area includes many rock glaciers and ice-cored
moraines (e.g. Lilleøren et al., 2013). Work is ongo-
ing to refine the LIA glacier extent of some glaciers
with detailed fieldwork and further analysis of re-
mote sensing data (e.g. Fernández-Fernández et al.,
2019; Tanarro et al., 2019). Apparently, many of the
debris-covered glaciers have not retreated much since
the LIA maximum, as the LIA outline overlies the
more recent outlines at several locations (Figure 11),
although considerable thinning has been observed
(Brynjólfsson, unpubl. data). Many of the debris-
free glaciers have retreated, as evidenced for example
by the frontal measurements of Gljúfurárjökull and
Tungnahryggsjökull (spordakost.jorfi.is).
The total area of glaciers on Flateyjarskagi de-
creased by 9 km2 in ∼1890–2019 (Table 2), close to
50% of their maximum LIA area. However, as for the
Tröllaskagi glaciers, the maximum LIA glacier out-
line has not been traced in detail by field measure-
ments, and the moraines have not been dated.
Other small glaciers
Glaciers in the 0.01–3.0 km2 size range (in the year
2000), are found in East, Southeast, South, West and
Northwest Iceland as well as in Kerlingarfjöll moun-
tains in central Iceland (see Figure 1, Sigurðsson and
Williams, 2008, and Sigurðsson et al., 2017, for fur-
ther information). The LIA maximum glacier outline
has only been traced from remote sensing data (with-
out detailed field mapping). These small glaciers were
systematically mapped in ∼2000 and again in 2017.
22 JÖKULL No. 70, 2020