Change in the earthquake activity in close to Herðubreið mountain

Sometime yesterday (24-October-2022) a change happened in the earthquake swarm close to Herðubreið mountain. I am not sure when that change happened and it probably took few hours to happen before I detected it. But the change seems to be that now the earthquake swarm is at two locations and not just one. The second change is that the earthquake swarm is now getting more intense. The earthquakes at the writing of this article are minor, only magnitude Mw0,0 to Mw2,7 at the strongest. Nothing above Mw3,0 so far, but that might change without warning. Depth of this earthquake swarm is around 2 to 3 km at the writing of this article.

Two swarms of red dots show the location of the earthquake swarm east of Askja volcano and south of Herðurbreiðartögl volcano. The earthquake swarm is now west and north of Herðubreið mountain
Earthquake activity close to Herðubreið mountain. Picture from Icelandic Met Office.

What is going to happen next is impossible to know. An eruption in this area has not happened for at least 12.000 years or even longer. I don’t know if stronger earthquake activity is required for this area for an eruption to happen. It already is rather fractured from older earthquake activity and rift activity, that makes it possible for magma to have easier paths to the surface without much earthquake activity. That is at least one idea on the situation in this area. I might be wrong on this, since I don’t have information on the finer details of the crust around Herðubreið mountain.

Inflation and earthquake activity in Askja volcano

Inflation has been increasing in Askja volcano over the last few weeks. According to latest news that inflation is now at 14 cm, since the inflation was detected at the end of August. On Saturday 9-October-2021 an earthquake with magnitude of Mw3,2 was detected in Askja volcano (I’ll try and add the picture later if I remember). This is was the strongest earthquake in Askja volcano in the last 20 years according to the news.

Askja is remote and there are no or limited amounts of web cameras in the area. With winter arriving going there is impossible for most people. If an eruption happens this winter the best view is probably going to be harmonic tremor data until pictures appears from Icelandic Met Office or someone with an air plane (if the weather allows for that).

Askja volcano placed on uncertain level and yellow alert for flight

Because if Askja volcano quick inflation, that is now currently at 7 cm, Department of Civil Protection and Emergency Management has declared uncertain level and yellow alert for flight.

Green triangles shows most of the volcanoes in Iceland as green. Only Askja and Grímsfjall are yellow. Krýsuvík volcano is orange in colour.
Current status of volcanoes in Iceland as of 9-September-2021. Copyright of this image belongs to Icelandic Met Office.

Inflation is quick in Askja volcano and is now at 7 cm. When or if that is going to result in an eruption is impossible to know. Current Askja volcano is what remains of a mountain that blew up in an large eruption in the year 1875 century. Most eruptions are just lava flows, unless they happen to start in a water, then explosive activity happens while water remains.

Askja volcano started inflating in August 2021

Icelandic Met Office published the news today that Askja volcano has started to inflate.  This inflation started in August 2021 and has been measured at 5 cm a month. The inflation is happening just outside the Askja lake in area known as Ólafsgígar (Ólaf craters).

Inflation map of Askja volcano. Triangle in the centre of Askja volcano caldera show the location of the inflation in red to blue colour.
Inflation in Askja volcano. Copyright of this image belongs to Icelandic Met Office.

It is impossible to know if this is going to result in any eruption. This inflation however seems to have resulted in earthquake activity in Askja volcano. Most of the earthquakes so far have been minor in magnitude.

Inflation map of Askja volcano. It show displacements in north - south and east - west directions and up displacement of 5 cm
Inflation in Askja volcano. Copyright of this image belongs to Icelandic Met Office.

Icelandic Met Office announcement

Land rís við Öskju (Icelandic)

Uplift signal detected in Askja volcano

Icelandic News

Grannt fylgst með landrisi við Öskju (Rúv.is)

Landris við Öskju í fyrsta sinn í áratugi (mbl.is)

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