In February 2021, Alaska’s Mount Veniaminof erupted, spewing clouds of ash and toxic gas into the atmosphere. Despite this, there were no obvious warning signs prior to the event itself, and the eruption continued for three days before it was detected by scientists monitoring the ice-clad volcano.
This was not the first time the Alaska Volcanic Observatory (AVO) had been caught unawares by Veniaminof, even with rigorous monitoring. In fact, of the thirteen eruptions that have taken place since 1993, all but two have been “stealthy.”
That is, they occurred without the warning signs that typically predict an eruption – namely a rise in seismic activity, increased levels of gas emissions and ground swelling or deformation. Now, scientists writing in Frontiers in Earth Sciences have identified certain characteristics that explain the stealthy nature of Veniaminof and others like it.
“Veniaminof is a case study in how a volcano can appear quiet while still being primed to erupt,” lead author Yuyu Li, a volcanologist at the University of Illinois, explained in a press release.
Read More: Activity at Alaska’s Mount Spurr Suggests That The Volcano Is About To Erupt
Stealthy Volcano Eruptions and When They Occur
Li’s team built a model to predict how magma flow and the shape, size, and depth of the magma chamber affects its behavior. The results were then compared to data collected from Veniaminof in the three years’ preceding the 2018 eruption.
From this, the researchers determined when and under what conditions a stealthy eruption is most likely to occur.
The results suggest a high flow of lava increases ground deformation, leading to precursory warning signs that can alert scientists to a potential eruption. In contrast, a low flow of lava into a small chamber was more likely to result in a surprise eruption. This fits with what observational data reveals about Veniaminof: it has a slower flow and a smaller chamber.
The effect is amplified when temperature is added to the model. The constant presence of magma warms the chamber, reducing the likelihood the rock will “fail” and cause tremors or deformation that volcano monitors would pick up. This makes a stealthy eruption more likely.
Read More: How to Stay Safe Before, During, and After a Volcano Eruption
Volcano Eruptions Without Warning
First, understanding the why means that scientists can more easily determine which volcanoes are more likely to erupt suddenly and with no warning – in short, those with slow magma flows, small chambers and warm rock.
But crucially, it may also enable scientists to develop more effective technologies and methods that would allow them to identify signs of a possible eruption at Veniaminof and other stealthy volcanoes, such as Stromboli in Italy and Merapi in Indonesia.
“To mitigate the impact of these potential surprise eruptions, we need to integrate high-precision instruments like borehole tiltmeters and strainmeters and fiber optic sensing, as well as newer approaches such as infrasound and gas emission monitoring,” said Li, who also acknowledges the potential of artificial intelligence. “Machine learning has also shown promise in detecting subtle changes in volcanic behavior, especially in earthquake signal picking.”
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Frontiers in Earth Science. Stealthy magma system behavior at Veniaminof Volcano, Alaska
Rosie McCall is a freelance writer living in London. She has covered science and health topics for publications, including IFLScience, Newsweek, and Health.
