Alaska’s Iliamna volcano last erupted in 1867, but its slopes often trigger seismic spikes due to falling rock and glacial ice.
A satellite image showing Alaska’s Iliamna Volcano “ready to rumble” has sparked renewed interest in the snow-covered peak, just as scientists recorded a spike in earthquakes on its slopes.
The image, taken on June 10 by the Operational Land Imager (OLI) on NASA and USGS’s Landsat 8 satellite, captured the volcano days before it saw an increase in seismicity around 4:30 am local time on June 15.
An increase in seismicity means frequently occurring small earthquakes, according to a report by US-based magazine Newsweek which first reported the development.
NASA satellite photo of Alaska’s Iliamna Volcano which towers more than 10,000 feet (3,000 meters) over Cook Inlet. The volcano can be seen lower slightly left of center. Regular seismic activity causes the mountain to rumble and cause avalanches. pic.twitter.com/Izz4ypKseq
— Black Hole (@konstructivizm) June 24, 2025
“Initially, the earthquake rate was nearly continuous, with several earthquakes per minute,” said the Alaska Volcano Observatory (AVO) in a post on its website, “but this has since slowed to a rate of about one earthquake per minute”.
Despite the flurry of tremors, scientists say the activity is likely not linked to an impending eruption.
“This activity is likely not caused by volcanic unrest,” the AVO explained, “but is instead caused by avalanches thundering down the volcano slopes”.
Iliamna last erupted in 1867 but still generates seismic activity roughly once every two years. “Its murmurs tend not to be signs of volcanic unrest but rather the signature of avalanches large enough to register on nearby seismic and infrasound instruments,” NASA highlighted in a blog post on its page.
“Although steam plumes occur on its eastern flanks, there has been no historical volcanic activity at Iliamna,” the AVO added.
