Yesterday, August 3, an eruption began in Meradalir, near the site of the 2021 Fagradalsfjall eruption.
The magma flow is said to be at least five times larger than that of last year’s eruption, although it is still considered a relatively minor eruption. The location of the eruption is especially favourable, as it is unlikely to affect infrastructure such as roads. The original fissure was recorded as 260m long, but has since shrunk to some 130m. This is common for such fissure eruptions, which tend to isolate around one or two craters.
The above picture from the Meteorological Office of Iceland shows a model of the most likely lava flow. While the model is an older one and was generated before the current eruption, it assumes a fissure in the same areas that are now active. As of now, the eruption and model conform to each other well, and it seems likely that the lava flow will follow the predicted path, away from important infrastructure. The Meteorological Office is currently at work generating a new, updated model.
Einar Hjörleifson, natural scientist at the Meteorological Office, has indicated that the eruption has very little ash, and as such does not pose any danger to air traffic. The prevailing northerly wind is also blowing most of the volcanic gas south towards the ocean. However, visitors to the site are still advised to use caution and not approach the lava, as the fumes can prove dangers in high concentration and over a long time. Einar also stated that although we cannot know for certain, the earthquakes are likely to abate during the eruption as pressure is relieved. So far, the eruption is behaving similarly to the Fagradalsfjall eruption of last year, and there is reason to believe it will continue doing so. As of today, August 4, there has already been a reduction in seismic activity by half, with the largest earthquake in the last 24 hours registered at M3.4.
As of now, the government has asked the public to avoid the area. Traffic to the eruption was originally closed as the situation was assessed, but people are currently not being turned away. However, there have already been search and rescue calls to the eruption site due to hikers sustaining injuries. The walk to the eruption site is a difficult one, at 17km [10.6mi] round trip. As always in Iceland, proper equipment and footwear are key, and visitors are advised to inform themselves of the conditions before setting out.
The Reykjanes peninsula is a very geologically active area. More can be read about it here.