Alaska Volcano Observatory

From Dixon and others, 2017: "A significant amount of melt water was observed in late June, a suspected outburst flood from a subglacial meltwater reservoir in the Redoubt Volcano crater. Ground investigations determined the source of this outburst flood to be melt from a snow and debris avalanche, similar to those that routinely occur on Iliamna Volcano (fig. 4 [in original text]). A review of web camera views indicates this event occurred after June 28, and seismic evidence suggests a start at 03:54UTC (19:54 AKDT) June29. The source of the avalanche was a steep canyon wall immediately west of the 2009 dome. The avalanche is composed of multi-year snow and ice entrained with rock debris and fragmental products of the 2009 eruption. The Aviation Color Code and Volcano Alert Level were not changed due to this outburst flood and remained at GREEN/NORMAL through the year."