The 2009 eruption of Redoubt Volcano continues. Over the past several days, the intensity of ash-production has decreased while a lava dome is growing in the summit crater. Therefore, Alaska Volcano Observatory (AVO)lowered the alert level to WATCH and aviation color code to ORANGE this morning. AVO continues to monitor the situation closely and the observatory is staffed 24/7.

Following last Friday's update, Redoubt had seven more powerful ash explosions through Saturday evening, with the resulting plumes reaching between 25,000 to 50,000 feet above sea level. In total, AVO has observed 18 major explosive events since the start of the eruption. The last major explosive event occurred at 19:23 AKDT on March 28 (03:23 UTC, March 29). Over the last few days, a diffuse cloud of volcanic gas, ash, and steam is rising to variable altitudes over the volcano, but mostly less than 15,000 feet above sea level. At times of more vigorous ash production, the cloud has risen as high as 25,000 feet. Lightning has been detected several times in conjunction with ash emission this week. Trace amounts of ash fall (less than 0.8 mm or less than 1/32 inch) have been reported at Kenai and at Valdez. The area in the immediate vicinity of the volcano is blanketed by a thin layer of ash visible in the AVO web cameras. The larger explosions produced lahars in the Drift River Valley and minor ash fall in areas across south-central Alaska including Anchorage. A broad layer of volcanic haze extended east of the volcano over the Kenai Peninsula, the Anchorage Bowl, and the Matanuska-Susitna Valley on March 31.

AVO overflights and photography have confirmed that a lava dome is actively growing in the summit crater. Occasional avalanches of hot blocks tumbling from the dome are traveling a short distance down the north flank of the volcano.

Seismicity at the volcano had been declining over the course of the week until around 8:00 AM AKDT Thursday morning. Since then small repetitive volcanic earthquakes have been visible on stations closest to the summit crater. These earthquakes have continued up to the time of this report.

Based on its past activity, the current Redoubt eruption is expected to continue for weeks to months. During this time, a cycle of relatively quiet periods of lava dome growth followed by explosive episodes of dome destruction will likely take place. Future explosions pose an ongoing threat of lahars in the Drift River Valley, trace to minor ash fall throughout south-central Alaska, and ash-related impacts to aviation.