Volcanic eruptions can begin without warning, but they are usually preceded by earthquakes and unrest that are detected by scientists monitoring the volcanoes. Eruptions can cause danger by lava flow, lightning, poisonous gases and ash fall. The ash from a single eruption can fall throughout the country depending upon the weather and winds. The falling ash can be unsafe because of poisonous gases, and is hazardous to consume and it especially poses a threat to animals. Clouds of ash can cause disturbances to air traffic. If an eruption starts under a glacier, it can generate a sudden glacial outburst floods that can affect peoples lives, property, and the environment.
Prevention measures during volcanic eruptions
- Always wear a helmet in the vicinity of eruptions.
- Avoid areas where ash is falling, because of the danger of lightning, and keep in mind that the falling ash can create total darkness. If hit by falling ash, take the shortest way out by moving perpendicular to the direction of the wind.
- Wear a dust mask or keep a wet cloth over your nostrils and mouth.
- Stay where the wind blows and do not go into low areas were gas can accumulate. The gas is a lethal poison, which in most cases has no smell and is difficult to detect.
- Shut windows in the path of the eruption and prevent fallen ash from entering the house through the chimney
An eruption from KATLA volcano under the glacier Mýrdalsjökull is one of the most dangerous eruptions in Iceland. The volcano has erupted once or twice a century and the last eruption was in 1918 with ash and glacial outburst floods.
Warning information: Eruption Emergency Guidelines Katla and Eyjafjallajökull
Katla information poster
During the last millennium Hekla has erupted 23 times, making it one of the most active volcano in Iceland and potentially dangerous. Recent eruptions were in Hekla in the years 2000, 1991, 1981 and 1980. A major eruption of Hekla was in the year 1947 that created a volcanic plume that rose to about 30 km in the stratosphere and lasted for 13 months.
HEKLA information poster
BÁRÐARBUNGA – HOLUHRAUN eruption
For six months in 2014 – 2015 (August – February) the Bárðarbunga erupted in Holuhraun. The eruption in Holuhraun was the largest in Iceland for 200 years (since the LAKI eruption in 1783) with SO2 gas emission that affected the population in Iceland.
Health effects of short-term volcanic exposure and reccommended actions (PDF table)