Jökull - 01.01.2012, Blaðsíða 134

E. Magnússon et al.
Figure 1. Location of study area. The Öræfajökull ice cap is shown with 100 m contours. Blue areas show
marginal lakes and the ocean. The grey area on the corner inset shows the volcanic zones of Iceland. Red areas
show active central volcanoes. The labels EVS, E and S represent the Eastern Volcanic Zone, Esjufjöll central
volcano and Snæfell central volcano, respectively. – Öræfajökull og nágrenni. Jökullinn er sýndur með 100 m
hæðarlínum. Blá svæði eru jaðarlón og sjór. Gráu svæðin á innfelldu myndinni sýna legu gosbeltanna, rauð
svæði virkar megineldstöðvar.
Since the settlement of Iceland (∼900 AD), Öræfajök-
ull has erupted twice, in 1362 and 1727. The Plinian
eruption of 1362, one of largest historical eruptions in
Iceland, had devastating consequences for the district,
both by lahars or jökulhlaup and tephra fall (Thorar-
insson, 1958; Sharma et al., 2008).
The Danish General Staff published the first topo-
graphic map of Öræfajökull in the beginning of the
20th century. It was based on trigonometric mea-
surements carried out in 1904 and was published in
the scale 1:200,000 and 1:50,000 (Generalstabens To-
pografiske Afdeling, 1904; 1905). The ablation ar-
eas of Öræfajökull outlets were next mapped by the
U.S. Army Map Service, using aerial photographs
from 1945 (Army Map Service, Corps of Engineers,
1950; 1951). These maps, published also in the scale
1:50,000, adopted the contour lines from the Danish
maps at higher elevations. It is only in the past decade
that new topographic maps of Öræfajökull, based on
aerial (Loftmyndir ehf., 2004, covering parts of the
132 JÖKULL No. 62, 2012