A new small lake has recently formed in the summit crater of Mount Spurr, the Alaska Volcano Observatory (AVO) informed in its latest bulletin.
This observation supports the suspicion that the recent seismic activity had been caused by a small magma intrusion (without leading to an eruption). The unrest at the volcano has calmed down again and a new eruption is not considered likely in the near future.
From the AVO bulletin:
„…recent seismic and deformation data indicate a possible minor intrusion of magma has occurred beneath the volcano over the last several months. While the formation of the lake is new, gas emissions remain low and seismic activity is declining, suggesting the probability of an eruption in the near future has not significantly increased. No surface changes have been observed at Crater Peak, the vent 2 miles (3 km) south of the summit associated with all historical eruptions.
„The lake first appeared between May 15 and June 15, and was well documented during a June 23 overflight (see photo below) when it had an area of about 1 acre (3800 square meters). The last time a crater lake formed at the summit of Mount Spurr was during seismic unrest in 2004 that did not lead to an eruption.
„The June 23 overflight also monitored gas emissions from the volcano and detected low levels of sulfur dioxide and carbon dioxide. The measured compositions are similar to background levels measured in previous years. Deep intrusion of magma is sometimes associated with anomalously high volcanic carbon dioxide emissions, but no such anomaly was detected during the overflight.
„Seismic activity beneath Mount Spurr has been above normal levels since spring 2024, but starting on May 20, the degree of seismic unrest has declined and remains slightly elevated (see figure below). The occurrence of deeper (>12.4 miles or 20 km) low frequency earthquakes has been above background levels since spring 2024. A small amount of deformation, consistent with a shallow (less than 3 miles or 5 km depth) source of inflation, has been observed in GNSS data. Similar to the earthquake activity, the rate of deformation appears to be decreasing.“ (Source: AVO)
