Náttúrufræðingurinn - 1953, Page 17
HVERSU MÖRG ERU HEKLUGOSIN?
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According to Thoroddsen, the eruption in the year 1554 took place in the moun-
tains north-east of Hekla. Actually it was south-west of the mountain. The present
writer thinks it probable that this eruption came from a row of small craters just
north-east of Raudöldur (cf. Fig. p. 71), now buried by the lava flow of 1947.
Hekla was certainly not responsible for the eruption of the year 1578. This is
quite evident from contemporary reports, given by authors such as Sigurdur Stef-
énsson (in his Qualiscunque descriptio Islandiœ, ab. 1590) and Arngrímur Jónsson
(in Brevis commentarius, 1592).
The eruption of 1619 was also not an Hekla eruption. A contemporary scholar,
Gísli Jónsson, bishop of Skálholt, relates in his Annalium in Islandia Farrago, 1637,
that this eruption was somewhere in the westem part of the Vatnajökull area.
Contemporary descriptions of the eruption in 1725 make it clear, that this one
took place only in the immediate surroundings of Hekla, but not also in Hekla
proper — as maintained by Thoroddsen.
In his Reise igiennem Island E. Ólafsson mentions fires seen in the lava fields
west of Hekla in 1754 — lasting three days. Thoroddsen listed these fires as an
eruption. It seems, however, very doubtful that this was an eruption at all.
A revised list of the Hekla eruptions is shown in Table I. According to that list
Hekla proper has erupted maximally 15 times, minimally only 13 times in histo-
rical time (viz. since and including the 1104 emption). Besides 5—8 eruptions
have occurred in the Hekla area, 1—3 of which coincided with emptions in Hekla
proper. It is probable tliat some or all of the eruptions in the Hekla area have
influenced the duration of intervals between the eruptions in Hekla proper.