Jökull - 01.01.2020, Blaðsíða 136

Sveakratern 1919 – Grímsvötn revisit 2019
Figure 6. Erik Ygberg with the horses next to the tent up on the even-surfaced glacier. The indication that it is
Erik on the picture comes from the article he wrote in the Swedish newspaper Aftonbladet 4th of October 1945.
– Erik Ygberg og hestarnir við tjaldið á sléttum jökli.
and crawled with caution forward as he expected a
crevasse. After only a few meters a wind gust came
and the whole world opened. He was at the brink of
an abyss, so he crawled in reverse back to Hakon,
the horses and the sledge. They withdrew in their
tracks and at a safe distance they pitched their tent.
The next day when they got out of the tent (Figure
6) they saw in front of them a huge depression in the
glacier, bathed in the sparkling sun. This depression
was surrounded on three sides by steep to near verti-
cal walls with the southern wall mostly composed of
outcropping rocks (Figure 1). The height of the sides
was estimated to be about 125 meters. The fourth side
was smoother and formed a valley in the glacier sur-
face, linking it to the upper reaches of Skeiðarárjökull
(Figure 1). Roped up they reached the floor of the
depression, which was covered with ice. In the south-
western part open water was present along the walls
of the depression (Figure 1). They reported steam ris-
ing from the rock and the origin of the sulfur smell
could be explained. The size of the crater was mea-
sured as 8 kilometers E-W and 5 km N-S. Erik and
Hakon realized that they were inside a huge volcano
and they inferred that they had found the source of the
jökulhlaups emerging from Skeiðarárjökull. The vol-
cano was baptized to Svíagígur or Sveakratern. This
name has not survived, after the eruption of 1934 the
old name of Grímsvötn was re-instated by geologists
Jóhannes Áskelsson (Áskelsson, 1936), Hans W:son
Ahlmann (Ahlmann and Thorarinsson, 1937) and Sig-
urður Thorarinsson (Þórarinsson, 1974).
Towards the east
Erik and Hakon left Grímsvötn on the 2nd of Septem-
ber and continued the expedition on a course due east
from the newly discovered “Sveakraten”). The thick
fog showed no intention of moving and in the follow-
ing days they followed a compass course. The fog lay
heavily over the landscape until the 4th of Septem-
ber, and on that morning they found themselves in a
crevasse area. The barometer indicated that they were
at an altitude of 1500 meters. The skies cleared away
and they could see all the way down to Hornafjörður.
This was a morale boost, they were close to the goal
of reaching the eastern margin of Vatnajökull! As the
number of crevasses increased they decided to leave
the sledge behind as supplies were running low. They
continued with two riding horses and one pack horse
that carried some of the equipment, but with a part
of it left behind. They had Hornafjörður in sight, but
had to descend down Heinabergsjökull, which proved
to be a challenge. They climbed down a steep slope,
a heavily crevassed section, went around a small hill
and passed over narrow ridges with deep crevasses
on each side. It took them more than ten hours to
cover two kilometers. On the 5th of September they
JÖKULL No. 70, 2020 133