The Alaska Volcano Observatory warns that more a more vigorous eruption may occur at any time, possibly due to a potential collapse of the new dome. In late May, 2009, activity decreased and the Alaska Volcano Observatory lowered the alert level. A nearly six-month period of relative quiet at the volcano ended on December 27, 2009, with renewed earthquake swarms. The AVO subsequently raised the alert level, and again warned of the possibility of a more vigorous eruption due to dome collapse. Aftermath of 2009 eruptions and prognosis for future activity On April 11, 2009, the Alaska Volcano Observatory released the following statement into the public domain on their USGS affiliated website regarding the aftermath of the 2009 eruptions of Mount Redoubt, and a prognosis for future activity. Summary The 2009 eruption of Redoubt Volcano continues. A lava dome is currently growing in the summit crater, accompanied by intermittent emissions of volcanic gases and minor amounts of ash. Additional explosive events are likely and could send ash to greater than 30,000 feet above sea level. Such a cycle of dome growth and explosive dome destruction may continue for many months. The potential for lahars (volcanic mudflows) and other flooding down the Drift River Valley remains, as does the potential for trace to minor ash fall on communities near Redoubt (e.g., the Kenai Peninsula Borough, The Municipality of Anchorage, and the Matanuska-Susitna Borough, and possibly more distant areas). Observations The 2009 eruption of Redoubt Volcano began with a minor explosion of steam and ash just after 13:00 AKDT on March 15. Major explosive events began at approximately 22:40 March 22 AKDT, and since then AVO has recorded more than 19 separate explosions. Plume heights, as measured by radar and confirmed by pilot reports, have exceeded 50,000 feet (15 km) above sea level on multiple occasions. To date, the largest explosion occurred at 05:55 AKDT April 4, lasted more than 30 minutes, and is comparable in size to the largest event of the 1989/1990 Redoubt eruption. Three major lahars (volcanic mudflows), on March 23, March 26, and April 4, have inundated the Drift River Valley and its downstream coastal fan. All of these reached the Cook Inlet and affected the Drift River Oil Terminal (DROT). The peak discharge rates of these lahars remains under investigation, but all are considered significant, and the April 4 event may have exceeded the size of any