AVO reported that on 16 September, a pilot flying downwind of Redoubt reported smelling a strong sulfur dioxide odor. A week later, residents of a cabin near Wadell Lake (25 km NE) reported loud noises coming from the direction of Redoubt. During an overflight on 27 September, scientists observed several fractures and circular openings in the upper Drift glacier that had not been seen before. They also noted that fumaroles atop the 1968 and 1990 lava domes were more vigorous than when last observed in mid-August. A distinct hydrogen sulfide odor was also evident, though no sulfur dioxide was detected by onboard instrumentation. The seismic network at Redoubt did not detect any abnormal earthquake activity. The Volcano Alert Level remained Normal and the Aviation Color Code remained Green.
Source: Alaska Volcano Observatory (AVO) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”