The chance of a shield eruption seems to be increasing

The probability of a shield eruption in the Sundhnúkagígar crater row increases with time. That would mean that the Reykjanesbraut Road is not the only infrastructure on the Reykjanes Peninsula that is in danger. Such an eruption could last for several years or even decades.

This is what volcanology professor Þorvaldur Þórðarson says in an interview with Morgunblaðið.

Shield eruptions often result in shield mountains, but the eruption must last for quite a long time to form large shields ​​such as Skjaldbreiður , which took about 30-100 years to form.

Most of the eruptions since last December have started between Mt Sundhnúkur  and Mt Stóra-Skógfell. If the next eruption occurs there, the probability of a prolonged eruption increases, according to Þórðarson. But how likely is this?

"It's a possibility, and I think the longer this goes on, the likelier it becomes," says Þórðarson and adds:

"If it continues like this, it will end up with an event that can become a very protracted eruption and then actually form a lava shield." There is at least one possibility, and if it happens, much more than Reykjanesbraut Road will go under the lava."

Not the most likely scenario

He states that this is not the most likely scenario, and in fact rather unlikely, but nevertheless the probability of this is increasing.

Could this eruption then last for a few months?

"Yes, or even years or decades."

He says that the general feeling among scientists is that lava shields are formed in one long eruption. However, it is not completely known what the lead-up to such eruptions is.

"They could start as many small eruptions, which then get bigger and bigger until we have such a large and powerful eruption that we create a lava lake in the main crater. It gets big enough to take in a significant amount and then splits lava from itself and spreads lava all around it. But the flow from below – it's just constant into this lava lake – so the eruption can last for much more than a month,” he says, pointing out that something like this happened in Hawaii in 1983. That eruption lasted for 35 years.