Rare earthquake by Langavatn on Mýrar
The time of the earthquake was at quarter to ten Thursday morning. Its source was five kilometres West of Langavatn, near the mountain Gjafi and the valley of Grjótárdalur. The earthquake occurred at a depth of 4.7 kilometres. Even though the earthquake isn’t big in comparison to the earthquakes that have been felt around Keilir lately, it must be taken into account that seismic activity isn’t very common in the area.
The earthquakes took place in the volcanic system of Ljósufjöll which stretches from lava field of Berserkjahraun all the way to the East of Grábrók by Bifröst according to the Eldfjalla og náttúruvárhópi Suðurlands (Volcanic and natural hazards group for the South Region) which reported about the earthquake on their FB website. Old craters that last erupted in historic times are in Hítardalur and Hraundalur, not far from the earthquakes source.
A long a period of unrest
Bjarki Kaldalóns Friis, Met Office natural hazards specialist, said the most likely reason for the observed activity are the old crates located in the area and there is no sign of volcanic unrest. Tremors in the area are rare.
The activity in the area caused interest earlier this year and in an interview with the agency last month Páll Einarsson, geophysicist, mentioned that it is unlikely to see lava in that area in a near future. The rule is that if no activity has been observed for a long period, the precursory signs of an eruption are also long.
“In this system no eruption has happened since the settlement age. It did though erupt in Rauðhálsar, a summit near to the West. A more than thousand years has passed since. It is rather likely that an eruption isn’t due for another couple of decades, though we are observing some fluctuations now. We could draw a great deal of knowledge from the eruption in Eyjafjallajökull, which is rather a mild volcano and has not erupted often. The eruption was preceded by an 18-year long period of unrest before magma reached the surface. There is probably some average. When it comes to Snæfellsnes, that period leading to an eruption is significantly longer” explained Páll.