Watching Volcanoes, One Signal at a Time

By Autumn McPherson

Photo courtesy of Karenna Merritt

David Fee, left, and Kareena Merritt, right, stand in front of Karenna’s display at the American Geophysical Union Fall conference in D.C.

Karenna Merritt, a UAF-Geophysical Institute graduate student who works with the Alaska Volcano Observatory, or AVO, is inspired to collect data on volcanoes. She studies the seismic and infrasound signals at Shishaldin, a frequently active volcano in the Aleutian Arc. According to Merritt, this volcano erupted three times between 2019-2020 and 13 times in 2023 alone. 

Merritt had always been interested in geology and volcanoes from growing up idolizing the beauty from the volcanoes around Washington State. She began her education at Western Washington University where she was later encouraged by her mentor, volcano seismologist Dr. Jackie Caplan-Auerbach, to join the graduate program with Dr. David Fee here at UAF due to his “semimonastic expertise and focus on volcanoes.” 

Within the last year that Merritt has been at UAF, she has attended hybrid meetings with the AVO to discuss the current volcanic activity. During these meetings, the topic of Mount Spurr was often brought up due to its constant unrest, more so now that the volcano is expected to erupt in the near future. 

Volcanoes are monitored by using seismic stations, infrasound sensors, webcams, and Global Navigation Satellite System stations. AVO organizes the number of earthquakes and their magnitudes, depths, infrasound spectrograms to determine if the tremor is present, as well as the location of the earthquakes related to the location of volcanoes. 

Due to the fact that Mount Spurr has continuous small earthquakes beneath it, AVO expects there to be an eruption soon, however, the location and frequency of the quakes is expected to change before the volcano erupts. Volcanoes like Mount Spurr, Redoubt, and Augustine are located near highly populated areas which can be damaging to those around it if it erupts as people would be breathing in ash. Eruptions can also affect flight patterns as if the ash were to enter the engine of a plane it could cause the plane to shut down, as well as obstruct the view of the pilots. 

Merritt said that working with AVO has been an “eye-opening” experience. She explained how particularly challenging it is to monitor remote and nearby volcanoes across Alaska due to Alaska’s size, weather, and wildlife. She expounded that there are 54 historically active volcanoes in the state, with nearly 100 others that have erupted in the past several million years. Merritt said that this is “a ton” of eruptions. 

Merritt then touched on the hot topic around Alaskan volcanoes for the last few months: Mount Spurr. She said that since it’s in Cook Inlet, it’s not very remote by Alaskan standards. “However, its conditions often complicate the monitoring process as webcam footage can be obscured due to low visibility, and snowmelt and/or glacial activity can introduce additional signals into seism acoustic and GNSS data.” Which, she said, means “a lot of patience and perseverance is needed in order to properly monitor Spurr unrest.” Yet with all the public interest in Spurr, this creates a challenge for AVO scientists. They need to inform the public, but they don’t want to cause panic. 

With Merritt’s work revolving mainly around analyzing Python scripts data, she uses software ObsPy to analyze and process the infrasound as well as the seismic data to see how the ground moves from an eruption. Her research group was able to create their own programs as well to help obtain this data. 

During the spring semester of 2025, Merritt enrolled in “Best Practices for Research in Alaska” at UAF which revolves around multiple topics relevant to field work in Alaska. She also attended a bear safety course, an aircraft training course, obtained a CPR/AED, and participated in first aid training to be safe during fieldwork explorations. 

This summer, Merritt is doing AVO fieldwork around Katmai for around ten days in hopes to understand the equipment that records the data she analyzes better. Merritt is also preparing for the 2025 Scientific Assembly of International Association of Volcanology and Chemistry of the Earth Interior (IAVCEI) which will take place in Geneva, Switzerland this summer. 

“For me, the hardest part about conducting research as a graduate student is simply time management. As an undergraduate, I attended classes, did research, had a part-time job, and had (somewhat) a social life, so I didn't anticipate the first year of graduate school being all that different. However, taking a full course load and making sufficient research progress was much harder than I anticipated! Now that I am mostly done with classes, I am looking forward to nearly full-time thesis research and the ability to take on additional research projects. It is a super unique opportunity to be able to work alongside experts in academia, agency, and industry, so I am always excited to come to work every day.”