What is going on in Bárðarbunga volcano

This is not a status update article. For Monday 10-November-2014 status update, please check last article. This is not going to be a long article since I have a long way to go in order to properly analyse all the data that has resulted from the eruption in Bárðarbunga volcano.

Activity in Bárðarbunga volcano before 16-August-2014

Activity in Bárðarbunga volcano before 16-August-2014 was a pattern of regular earthquake swarms and dyke intrusions. That was considered normal behaviour in Bárðarbunga volcano. It has to be considered if this where in fact the long term signs that eruption was going to happen soon. Earthquake swarms where also common in Dyngjuháls area, often with earthquakes that had magnitude 3,0 and stronger.

Nineteen weeks before 16-August-2014

It seems that some nineteen weeks before 16-August-2014 a critical point was reached in Bárðarbunga volcano. At that point it seems that pressure had started to rise inside the volcano. This resulted in change in earthquake activity that lasted until 16-August-2014 when magma started to break outside the magma chamber and making its way to the surface. This change in activity in Bárðarbunga volcano appears clearly on Week 15 and Week 16 and onwards.

Current changes in Bárðarbunga volcano

Currently Bárðarbunga volcano is subsiding and at the moment it is not going to start a caldera collapse if it continues in the same way as it has been doing for the past two and half month. Far as I can tell, it seem that magma is now being drained from two dykes (or sill) in Bárðarbunga volcano, while the dyke exit point is rather deep, with depth around 5 – 8 km (best estimate and it might be wrong). This appears to be drainage from the top, magma is going down the mountain (far as I can tell and that might be wrong too) and into the dyke. Rather than just rising from depth and going into the dyke, but that is also happening at the moment. How much magma is at work here I don’t know, it is however clear that there is enough magma in Bárðarbunga volcano to continue the eruption in Holuhraun for many more months. The drainage of the sill(s) explains the earthquake activity in Bárðarbunga volcano, it also means this earthquake activity is going to continue for many more months. It also means that larger earthquakes that have higher magnitude than 5,7 can happen, even if they have not done so yet.

The rifting activity

It seems that the eruption in Bárðarbunga volcano has started a rifting in Eastern volcanic zone in Iceland. That activity is going to continue for decades at least. This rifting means that more fissure eruptions are going to take place, both under Vatnajökull glacier and outside it (like Holuhraun eruption).

What is going to happen next?

While there is no way to be certain what is going to happen next in Bárðarbunga volcano since its eruption history is mostly unknown and has not been observed with instruments before. As the time passes the image is going to get clearer. For the moment Icelandic emergency authorities are preparing for an eruption under Vatnajökull glacier. Since an rifting is going to start south of Bárðarbunga volcano one day, when that might happen is not clear, since the situation south of Bárðarbunga volcano is more complex and has factors at work. One of those factors is Hamarinn (loki-fögrufjöll) volcano. It is clear that Bárðarbunga might or is likely to trigger a eruption in that volcano without warning. When that might happen is not known and that is always the case with volcanoes and possible eruptions.

New activity update for Bárðarbunga volcano is going to be written tomorrow (12-November-2014).