By MARY DURLAK
Published July 31, 2023
UB researcher Stephan Kolzenburg is having a busy summer studying volcanoes around the world to deepen scientists’ understanding of lava flow.
“When Nyiragongo erupted in 2021,” Kolzenburg says, “more than 20,000 people were left homeless, three hospitals were destroyed and 30 people died.” Nyiragongo, one of the world’s most dangerous volcanoes, is an active volcano in the Democratic Republic of the Congo.
Kolzenburg, assistant professor of geology, College of Arts and Sciences, earlier this year received a $410,626 grant from the National Science Foundation to study Nyiragongo and another nearby volcano, Nyamulagira. This work involves a junior researcher from the Goma Volcano Observatory, Albert Kyambikwa, who is a graduate student in Kolzenburg’s laboratory. While the research will focus on these volcanoes, Kolzenburg expects their findings will contribute to a better understanding of volcanic rheology — the term “rheology” comes from the Greek word for “flow.”
When Litli-hrútur in Iceland erupted on July 10, one of Kolzenburg’s PhD students, Martin Harris, immediately packed up a field rheometer prototype developed in Kolzenburg’s lab and flew to Iceland with it to meet collaborator Oryaëlle Chevrel, who has developed a complementary rheometer prototype at the Université Clermont Auvergne in France. Additional fieldwork collaborators William Moreland, Ármann Höskuldsson and Thor Thordarson from Háskóli Íslands (University of Iceland) joined them.
“We want to measure flow properties of lava while it’s hot,” Kolzenburg says. “We’re interested in the viscosity of the lava because that will determine how fast and how far it will go.”
Viscosity is the measure of how hard it is for a fluid to flow. Lava’s viscosity depends on the location of the opening where the lava flow begins, the terrain and the composition of the lava. The viscosity also varies as the lava slows and cools until, finally, it hardens into rock. Magma is the molten rock found beneath the earth’s surface; once it breaks through to the surface, it’s considered lava.
“At Nyiragongo,” Kolzenburg says, “we want to collect enough data to optimize a model for that specific volcano in collaboration with Oryaëlle Chevrel from the Université Clermont Auvergne. When the next eruption comes along, we want to integrate the model with satellite data recorded by collaborator Diego Coppola at the University of Turin. The satellites use heat sensors that can tell us how much magma is coming out of the ground and where it is, and we can use that information in the models.”
The model will be a tool that can be adapted to predict lava flow rates at other sites.
In LAVAP-UB, Kolzenburg’s lab, sophisticated equipment allows controlled study of molten rock. “We can melt rocks, stir them around and measure how hard it is for this material to flow,” he says. “And we can better understand when it cools and turns back into rock again.” The equipment can work with material as hot as 1700° C.
The next stop for Kolzenburg and his team is Lassen Volcanic National Park in northeast California, which features several types of volcanoes. “I was always interested in science,” he says, “and in geology, I found a science that incorporates a little bit of everything. And I get to be outside!”