Jökull - 01.01.2020, Page 22

Glacier extent in Iceland, 1890–2019
Figure 8: The extent of Drangajökull ice cap at several times since the LIA maximum. Drangajökull reached the maximum
LIA extent a few decades earlier than most glaciers in Iceland, around 1850 (Þórarinsson, 1943; Brynjólfsson et al., 2015;
Harning et al., 2016). Two ∼1850 extents are presented, published by Harning et al. (2016) (chosen as the maximum LIA
extent and sent to GLIMS) and Brynjólfsson et al. (2014). The 1912 outline from the map of the Danish General Staff
(Danish Geodetic Institute, 1941a) for the southeastern part of the glacier is shown for comparison. – Útlínur Dranga-
jökuls á mismunandi tímum frá hámarki litlu ísaldar. Drangajökull náði mestri útbreiðslu á litlu ísöld um 1850, nokkrum
áratugum fyrr en flestir jöklar á Íslandi (Þórarinsson, 1943; Brynjólfsson o.fl., 2015; Harning o.fl., 2016). Tveir möguleik-
ar á hámarksútbreiðslu jökulsins eru sýndir, annars vegar skv. grein Harning o.fl. (2016) og hins vegar skv. grein Skafta
Brynjólfssonar o.fl. (2014). Sú fyrrnefnda var valin til þess að senda til GLIMS. Útlína jökulsins suðaustanmegin frá 1912
er fengin af korti danska herforingjaráðsins og sýnd til samanburðar við hámarksútbreiðslu um 1850.
2019, −1.3 km2 a−1, and similar during the time pe-
riod ∼1850–1945, −1.1 km2 a−1 (Table 3).
The recent retreat history of Drangajökull is de-
scribed in Magnússon et al. (2016) and Belart et
al. (2020). The LIA glacier history has been ex-
tracted from historical accounts (Þórarinsson, 1943),
the analysis of moraines, lake sediments and exposed
dead vegetation emerging from beneath the ice cap
(Brynjólfsson et al., 2014, 2015; Harning et al., 2016;
Anderson et al., 2018). From these records, it is
known, that the different outlet glaciers, as well as
other parts of the ice cap did not reach the maximum
LIA extent simultaneously. Sigurður Þórarinsson con-
cluded, based on historical accounts about destruc-
tion of farmland, that the outlet glaciers of Dranga-
jökull reached their maximum LIA extent around the
middle of the 18th century (Þórarinsson, 1943; Þórar-
insson, 1974). They reached almost the same extent
shortly before the middle of the 19th century, there-
after slowly retreating to the end of the century. This
is similar to the conclusions of Harning et al. (2016),
that the final expansion to the peak LIA extent was
most likely reached around the middle of 17th or the
18th centuries.
JÖKULL No. 70, 2020 19