|Start:||January 2, 2009 ± 30 Minutes||Observed|
|Stop:||January 21, 2009 ± 2 Days||Observed|
|Tephra plume: ||
|ColHeight: ||6000 m |
|Duration: ||2 short bursts of possible explosive eruption observed within 19 days |
On December 23, 2008, AVO noted a persistent thermal anomaly at Cleveland and raised the volcanic alert level and the aviation color code to Advisory/Yellow on December 24. Clouds obscured satellite views of Cleveland until December 28, when a clear view showed that the December 23 anomaly persisted.
On the morning of January 2, 2009, a brief but explosive ash emission was detected in satellite images of Cleveland. The ash plume reached an altitude of about 6 km (20,000 ft), drifted east-southeast about 240 km (150 mi) and dispersed over the North Pacific. A minor thermal anomaly was observed on January 4, and retrospective analysis of satellite imagery showed a possible ash emission early in the morning on January 21. The most recent thermal anomaly associated with this activity was January 26, 2009.
Based on lack of activity since late January, AVO lowered the Aviation Color Code and Alert Level for Cleveland to UNASSIGNED on Friday, May 1, 2009.