|Start:||February 18, 2012 ||Observed|
|Stop:||February 18, 2012 ||Observed|
|Tephra plume: ||
On February 18, 2012, AVO detected volcanic tremor from 15:23-15:27 UTC, followed by numerous small events for about an hour at Kanaga Volcano. A possible weak ash cloud about 8 km in length was detected in AVHRR satellite data from 15:35 UTC, about 39 km (24 mi) NE of the volcano.
Because of the new unrest and possible explosive activity with likely ash cloud, AVO raised the alert level to ADVISORY and the aviation color code to YELLOW.
Somewhat elevated seismicity continued at Kanaga on the 19th, but was not detectable on the 20th. Photographs taken by a local observer on the 19th showed a small steam plume issuing from Kanaga's summit. Low-level tremor was detected on the 25th. On March 2, citing continued background-level seismicity, AVO returned the alert level of Kanaga to NORMAL and the aviation color code to GREEN.