Nomination of

SURTSEY – NOMINATION FOR THE UNESCO WORLD HERITAGE LIST
Stórhöfði and Sæfell-Helgafell on the island of
Heimaey. Two volcanic eruptions are known with
certainty in historic times: the Surtsey eruption of
1963–1967 and the 1973 Eldfell eruption on
Heimaey. A small submarine eruption may have
occurred on the sea floor southeast of Hellisey in
1896. Furthermore, four young submarine
volcanoes have been discovered, so that
altogether 24 volcanic eruptions are known to
have occurred within the Vestmannaeyjar system
during the Holocene (Sveinn P. Jakobsson 1979).
In addition to the submarine rises produced by
the Holocene eruptions, numerous hills and
peaks on the sea floor (Fig. 2.4) presumably
represent remnants of more than 40 Late-
Pleistocene submarine volcanoes. Most of the
volcanoes in the Vestmannaeyjar system are
relatively small.
As a large part of the Vestmannaeyjar volcanic
system is submarine, its geographical limits are
difficult to delineate exactly; however, it reaches
about 38 km from southwest to northeast and 29
km from northwest to southeast, covering an area
of 900–1000 km 2 , where the average depth of the
Aerial view to the southwest of the Vestmannaeyjar
archipelago. Elliðaey and Bjarnarey are in the
foreground, Heimaey in the middle and Surtsey in the
far background. (Photo: Ragnar Th. Sigurðsson 2000).
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sea is about 70 m. The volume of volcanic rock
extruded within the Vestmannaeyjar volcanic
system during the Holocene period has been
estimated as ≥ 3.5 km 3 , which is one order of
magnitude less than the output of the highly
active Hekla and Katla volcanic systems.
Investigations on the Vestmannaeyjar shelf
(Sveinn P. Jakobsson 1982; Kjartan Thors and
Jóhann Helgason 1988) indicate that local
submarine as well as subaerial volcanism was the
source of the material building up the marine
shelf and that for the most part this build-up has
probably been ongoing for the last 100,000 years.
The main activity in the Vestmannaeyjar
volcanic system has occurred in and around
Heimaey (Fig. 2.4), which has accordingly
formed a topographic high. Indeed, it has been
proposed that Heimaey is evolving into a central
volcano (Sveinn P. Jakobsson 1979). On the other
hand, there are strong indications that
Vestmannaeyjar system volcanism is episodic.
The youngest Late-Pleistocene tuffs and lavas of
the Norðurklettar Formation seem to have all
been deposited within a short time interval. There
also appears to have been a major volcanic
episode 5,000–6,000 years ago, leading to the
formation of Stórhöfði and Helgafell on Heimaey