Importance of accurate volcanic forecasting erupts from scientific study

By JP Legarte, Investigative News & Longform Editor

Lilian Lucas, senior in LAS, first started research during the second semester of her freshman year and joined a lab group due to her interest in volcanology. Now, she has had the opportunity to lead a study focusing on the impact of glaciers on volcanoes.

“We really don’t know the impact that glaciers have on volcanic systems,” Lucas said. “That’s not very well constrained, so what we were interested in doing is constraining the impact, and so, in the future, we can forecast the eruptions of future volcanoes better just by knowing this impact.”

Jack Albright, a graduate student studying geology and one of the study’s researchers, emphasized everyone’s interest in volcanoes and the research opportunities available through the Aleutian Islands — an island chain off the coast of Alaska spanning across the Pacific Ocean known for their high volcanic activity with 57 volcanoes in total.

“Wherever cool volcano stuff is happening, we like to look at it,” Albright said. “In particular, (professor Patricia Gregg) has a number of grants to look at and study volcanoes in the Aleutian Islands. They are some of the most active volcanoes in the United States.”

Both Lucas and Albright referenced the importance of Westdahl Peak, located in the Aleutian Islands. Lucas cited Westdahl Peak as the inspiration for the study since they wanted to explore the potential impact of the glacier on the timing of eruptions after Westdahl never erupted in 2010 despite being predicted to do so.

In addition to noting the presence of the ice cap, Albright discussed how the ground at Westdahl can bulge out during inflation, which tends to indicate that an eruption will soon follow.

“It’s kind of like you’re breathing in, your lungs are expanding and then your chest moves outward,” Albright said. “Your chest is the ground surface, and your lungs are the magma chamber.”

Albright mentioned that one hypothesis considers how the weight of the ice cap keeps the rock from opening and bursting like a balloon.

“The ice is basically acting as another load,” Albright said. “It’s really equivalent to if that magma chamber was just a little bit deeper and had a little more rock on top, except that it’s more ice on top, and so it’s the actual, physical weight of having that ice there (that) increases the confining pressure around the magma chamber …  The weight of the ice is basically holding the whole thing closed.”

For Westdahl Peak, the researchers discovered that the difference between the presence or absence of ice in forecasting models was about seven years. In other words, the presence of ice delays eruption by around seven years compared to if the ice was not there.

The researchers then considered factors and impacts such as better forecasting, disaster prevention and maintaining public trust.

“We want to be able to protect local populations,” Lucas said. “There are a lot of airplanes and shipping routes that go over this region … If an airplane goes over a volcanic eruption, it could go down, so that’s a big part of why we want to better forecast these eruptions.”

Albright explained that if people were to attempt to forecast the eruption of Westdahl without the incorporation of ice in their models, then they would be sending out warning signals and implementing evacuation procedures seven years too early.

“One of the hard things about hazard mitigation is that, if it’s a false alarm, you kind of erode that public trust,” Albright said. “In this case, not just for the Aleutians but also for other ice-capped volcanoes, we’re trying to build tools to help improve the accuracy of those models when forecasting when an eruption might happen.”

Albright expanded upon important factors other than ground surface bulging such as seismicity and gas chemistry that need to be considered and explored so that more holistic models of magma systems are constructed for more accurate forecasting.

“If we can find ways to build our models in order to be able to say something about that chemistry or the seismicity, then we can fold those data in and narrow down that range of possibilities a little bit more,” Albright said.

While the study focused mainly on the impact of ice and glaciers on volcanic systems, Lucas offered her thoughts regarding how the study could potentially connect to the greater environmental conversation.

“To tie into environmental issues and the glaciers melting, pretty much the times to eruptions for these systems without ice are less, so we could see according to these models more frequent eruptions of volcanoes if we don’t have that presence of the ice on the system,” Lucas said.

When considering future investigations she would be interested in pursuing, Lucas noted the potential to experiment with volcanic systems and models further.

“I would like to have a system where we load the system and then let it relax and then see how the ice then affects the times to eruption when we do that kind of stuff,” Lucas said. “I just like to play around with the model and see what we could do.”

 

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