After the eruption of the Eyjafjallajökull in 2010, many people in the countries close to Iceland lookout for more to come. Every decade, some of the many volcanic systems of Iceland show signs of a magma influx into their roots. No wonder that slight worries, or even deep concerns, may trouble neighbours of the island from time to time. At least four centres of volcanic systems show signs of unrest. Look here for entries on the unrest during the coming weeks.
The large volcanic ridge of Hekla (1,495 m), towering north of the Southern lowlands, started a cycle of activity in 1104 after a long repose. Until 1948, the volcano erupted once or twice every century. Large lava flows and a substantial amount of ash and pumice characterized the middle-sized to large eruptions.
During the initial phase of Hekla’s eruption in 1947, Hekla sent ash all the way to Scandinavia. The eruption went on for 13 months but without being felt elsewhere outside of Iceland.
During the latter part of the 20th century and into the 21st, Hekla erupted roughly once every decade. The eruptions were rather short, lasting up to about 50 days and the volume of erupted magma less than during the former period. The last eruption occurred in 2000. Until now, Hekla has kept quiet but, according to data from the monitoring system, swelled and reached, and overstepped, the pre-eruption state from 2000. This means that an eruption can break out anytime but not that it is imminent. Days, weeks, months and years can elapse until Hekla opens up. People climbing the volcano are at risk because experience tells us that an eruption starts with very short notice, obtained from the monitoring system. The last four Hekla eruptions did not cause problems in mainland Europe. Occasional small earthquakes occur in Hekla. (Next: Bárðarbunga)
Ari Trausti Guðmundsson is a geoscientist and author of a number of books and documentaries/TV programs on the geology af Iceland, especially volcanology and glaciology. He is a member of the team that created LAVA and wrote the script for the exhibition.