USGS Volcano Hazards Program Volcano Update
A brief explosion occurred at about 21:29 UTC December 28 (12:29 AKST) according to signals detected on distant seismic and infrasound instruments. It is possible that a very minor ash cloud was generated but, if so, it was too small to be observed in satellite data. Following the explosion, elevated temperatures have persisted at the summit of Cleveland. No further explosions have been detected.
Update in Common Alerting Protocol (CAP) format