Scientists have recently reported that the Iliamna Volcano, situated near the Cook Inlet in southern Alaska, is showing signs of activity after being dormant for over a century. Although these rumblings may indicate volcanic movements, NASA has cautioned that they could also be precursors to a significant avalanche rather than a volcanic eruption.
The Iliamna Volcano last erupted in 1867, marking a significant period of dormancy. Despite this, it has been known to produce low-level activity, occasionally rumbling every few years due to large avalanches that are substantial enough to register on nearby seismic and infrasound instruments. NASA has noted that recent seismic events have raised concerns among scientists at the Alaska Volcano Observatory (AVO).
On June 15, the AVO reported a notable increase in seismic activity around Iliamna Volcano. This escalation lasted for several hours and was characterized by nearly continuous tremors. Prior to this uptick in activity, the Operational Land Imager aboard the Landsat 8 satellite captured an image of the volcano on June 10, which provided a visual reference point for scientists monitoring the situation.
According to the AVO, the seismic vibrations observed recently closely resemble those that have historically been linked to the initial slipping between rock and ice, a precursor to large avalanches on the volcano. The unique geological features of Iliamna, which include a combination of glacial ice, weakened rock, and volcanic heat, often contribute to its propensity for massive avalanches.
The peak of Iliamna Volcano is enveloped in glaciers, snow, and ice, resting on a base composed of Jurassic-era granite. Since its last eruption, the volcano has shown intermittent activity, with recorded instances of smoke and light ash emissions in 1876, 1933, 1941, and 1947. Some unverified reports indicated additional smoke and ash in late winter 1956 or early spring 1957. However, the last confirmed activity occurred in 1958, when four columns of vapor were observed shooting from vents on the volcano's eastern side.
Despite its remote location within the Chigmit Mountains of Lake Clark National Park and Preserve, Iliamna Volcano is closely monitored by volcanologists due to its potential hazards. The surrounding regions include several communities, such as Pedro Bay, Port Alsworth, and Anchorage, all of which fall within a 200-mile radius and could be impacted in the event of a significant eruption.
The AVO is responsible for monitoring not only Iliamna Volcano but also 51 other active volcanoes throughout Alaska. This includes the nearby Redoubt Volcano, known for its more frequent eruptions. Scientists continue to assess the situation, ensuring that they are prepared for any developments that may arise from the current activity at Iliamna.
