in the central volcano and are believed to last from a few days up to 7 months. Activity is periodic with episodes of high activity (60-80 years) with 6-11 eruptions
per 40 years, alternating with low activity episodes (60-80 years) with 0-4 eruptions
per 40 years. Four large effusive eruption are confirmed during the last 8000 years. The youngest one is the 1783-1784 Laki fires (Skaftáreldar in Icelandic
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