Earthquakes in 2022 near Mount Edgecumbe bring research team to Kruzof Island

SITKA, Alaska (KTUU) - In May 2022, a series of small earthquakes rumbled near Mount Edgecumbe. Geophysicists think those earthquakes were due to the ground around Mount Edgecumbe lifting slightly because the magma underneath it is pushing toward the surface.

Last week, an international research team — including scientists with the University of Alaska Fairbanks Geophysical Institute — were on Kruzof Island.

“We’re down here to do some gas measurements,” said Claire Puleio, Ph.D., volcanology student. “So we’re looking for diffuse CO2, which is really low levels of CO2 and we’re measuring, kind of, all over the island, Kruzof Island, as well as on Edgecumbe summit itself.”

The goal is to figure out what might be going on in the subsurface of the volcano.

“What we suspect is that degassing from the magma chamber, which is very deep below the ground, sometimes you can have magmatic gases, that degas from that chamber and then travel to the surface and it can give us a little bit of a better idea of what’s going down, really deep below the surface,” Puleio said.

The CO2 samples they are collecting might not be from the volcano.

“It could be just from plants, and biology, biologic processes, might not necessarily be magmatic,” Puleio said.

The team is collecting samples that will be sent off for a carbon isotope analysis, which will be able to tell them the source of the CO2.

“It’s all in response to that activity that we noticed about a year ago, that kind of pointed to some inflation and seismicity that began in about 2018,” Puleio said.

According to Puleio, people who hike on Kruzof Island have noticed bubbling in the ground.

“We’ve gone back to those areas to see if we see the same bubbling,” Puleio said. “And we have found that bubbling that they saw, which is really great, really exciting for us. And we’re taking some samples of some of that bubbling that we’ve seen to see if it is magmatic or not. It could just be biologic, but that’s been exciting to find what some folks from Sitka found and told us about.”

Copyright 2023 KTUU. All rights reserved.