Alaska’s Iliamna Volcano Shows Seismic Activity for the First Time in Over 150 Years

Kokcha News Agency reports that the Alaska Volcano Observatory has detected several hours of seismic activity beneath Iliamna volcano, located in the Chugach Mountains near the Cook Inlet. This volcano, which has been inactive for over 150 years, is now showing rumbling signals that scientists are closely monitoring.

Experts note that Iliamna last erupted in 1867 but has experienced minor trembling and rumbling associated with large avalanches over the years, particularly due to melting ice and snow loosening rocks. The recent activity was preceded by a satellite image taken by Landsat 8 on June 10, which showed initial signs of shifting between rock and ice—similar to early indicators observed before past avalanches.

NASA clarified that this seismic activity is more likely related to avalanches or glacier movements rather than an imminent volcanic eruption. The region experienced a “seismic excitement” on June 15, with almost continuous activity for several hours, raising brief concerns among local populations and scientists.

Historical Activity & Current Status:
The last recorded minor activity included a few plumes of smoke and ash in 1958, with no major eruptions since then. The US Geological Survey (USGS) and the Alaska Volcano Observatory currently classify Iliamna’s activity level as “normal,” with no immediate threat. Nearby communities within a 320 km radius—including Pedro Bay, Port Alsworth, and Anchorage—are being monitored for potential impact.

In addition to Iliamna, the observatory tracks 51 other active volcanoes in Alaska, including the neighboring Redoubt volcano, which is considered more explosive. Despite the recent seismic signals, the current alert level for Iliamna remains at “normal,” indicating that an eruption is not imminent but remains under close observation.