With reoccurring earthquakes, floods and other eruptions many are wondering: When will Katla erupt and if it does, for how long.
Katla, the volcano based in Mýrdalsjökull glacier has erupted at least 20 times since the first settlers came to Iceland. The eruptions have lasted for two weeks up to four months. The latest eruption in 1918 lasted for 24 days, the eruption in 1823 was 28 days but the biggest Katla eruption in historical times in 1755 lasted about 120 days.
Katla 1918 eruption
Sometimes eruptions in Katla have been preceded by eruption in Eyjafjallajökull. This happened in 1821 and on other occasions. Such an eruption in Katla has always come within two years of an eruption in Eyjafjallajökull.
The time since the last visible Katla eruption is now 93 years, but some geologists think that a small eruption may have been below the glacier in 1955, resulting in a flood in Múlakvísl. On July 9 2011, a flood in Múlakvísl took away a bridge. Possibly this reduced the pressure on the volcano to erupt.
On the average Katla erupts every 50 years and the longest still period before the current one was 80 years. The shortest “down” period was 14 years.
Many people are speculating on when Katla will erupt again. This is not new. In 2004 Freysteinn Sigmundsson of the Nordic Volcanic Center said that he expected an eruption in Katla within three years and very likely within five years.
Eruptions are very hard to predict and a well known Icelandic geologist, Sigurdur Thórarinsson, said in 1975 that the only thing that could be said with certainty was that the eruption was getting closer every day.