Today’s Image of the Day from NASA Earth Observatory features the Iliamna Volcano, which recently experienced a burst of seismic activity on June 15, 2025. 

According to experts, the tremors were not likely to be warning signs of an impending eruption. Instead, the shaking was probably triggered by ice or rock avalanches. 

The volcano is currently considered dormant, with no elevated alert levels or signs of eruptive activity.

“Towering more than 10,000 feet (3,000 meters) over Cook Inlet, Alaska’s Iliamna Volcano last erupted in 1867. Once every couple of years, however, the mountain still rumbles,” noted NASA.

“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.”

The dramatic landscape of Iliamna 

Iliamna is a glacier-covered volcano about 130 miles southwest of Anchorage and 30 miles southwest of the more active Redoubt Volcano. Both are located in the Lake Clark National Park and Preserve. 

Glaciers have carved deep, U-shaped valleys that stretch from Iliamna toward the sea. Just south of the peak, Chinitna Bay is a popular spot for seeing brown bears.

The region’s dramatic terrain is the result of a long history of glacial activity, tectonic uplift, and volcanic shaping. Snow and ice persist year-round at high elevations, feeding creeks and rivers that support wildlife and vegetation at lower altitudes. 

The contrast between icy peaks and lush coastal plains makes Iliamna’s surroundings both ecologically diverse and visually striking.

A flurry of seismic activity 

The image of Iliamna Volcano was captured on June 10, 2025, by the Operational Land Imager (OLI) on Landsat 8. According to the Alaska Volcano Observatory (AVO), a flurry of shaking rattled Iliamna a few days later.

“Seismic activity picked up at about 4:30 a.m. local time on June 15 and ramped up to a ‘nearly continuous’ rate, the AVO reported. It slowed to a cadence of about one seismic event per minute and then returned to background levels around 2:30 p.m.,” NASA reported.

“The AVO did not have enough information as of June 16 to determine the size and location of any slide that may have occurred that day. However, the signals they recorded were similar to those caused by the initial slipping between rock and ice that preceded large avalanches on the volcano in the past, they said.”

Rock and ice avalanches on Iliamna 

Glacial ice, heat from the volcano, and weakened rock come together on Iliamna’s slopes to create the perfect setup for huge landslides, noted NASA. 

Researchers say that it’s unusual to see so many large ice and rock avalanches in one place, making Iliamna a valuable natural lab for studying how and why these events happen. 

While Iliamna is far from towns or cities, similar conditions in more populated mountain areas could be dangerous for nearby communities.

Glacier melt and slope stability

In recent years, scientists have warned that warming temperatures are accelerating glacier melt across Alaska, potentially destabilizing the slopes of glacier-covered volcanoes like Iliamna. 

As ice retreats and thins, it can remove the natural support that holds rock in place, increasing the risk of avalanches and landslides.

Climate change may also be influencing the frequency and intensity of these non-eruptive seismic events. As permafrost thaws and glaciers lose mass, the delicate balance between ice, rock, and heat is disrupted, sometimes leading to sudden and dramatic collapses.

Indicators of environmental change

Volcanoes such as Iliamna serve as critical indicators of broader environmental changes. The patterns of seismic activity and ice loss on their slopes offer researchers valuable insight into how the Earth’s cryosphere is responding to global warming.

While Iliamna is a remote volcano that poses no direct threat to people or communities, its behavior raises important questions about the future stability of other glaciated volcanoes worldwide. 

As climate change continues to reshape mountain environments, understanding the interactions between ice, rock, and volcanic heat will be vital for anticipating hazards in both high-latitude and high-altitude regions.

Image Credit: NASA Earth Observatory 

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