MVO reported that most of the rockfalls and pyroclastic flows detected during 20-27 August originated from a vertical face on the SE side of the lava dome and traveled W down Gages valley and E down the Tar River valley. The pyroclastic flows traveled no longer than 1.5 km and produced weakly convecting ash clouds that rose a few hundred meters. The Hazard Level remained at 3.

Source: Montserrat Volcano Observatory (MVO)

An eruption from Galeras that began at 0400 on 25 August prompted INGEOMINAS to raise the Alert Level to I (Red; "imminent eruption or in progress"). Meteorological cloud cover initially prevented visual observations of the summit. Seismicity associated with the eruption continued for a period of about 12 hours and gradually declined in the afternoon. The Alert Level was lowered to II (Orange; "probable eruption in term of days or weeks"). Scientists aboard an overflight later that day observed ash-and-gas emissions from multiple areas of the active cone, and thermal anomalies that were detected on the N side of the cone. Ash fell to the NW, as far away as 30 km. According to news articles, about 7,000 were requested by officials to evacuate, although few left their homes. During 26-31 August at least 12 earthquakes, M 2-4, were located within a 2-km radius from the crater, at depths not more than 3 km. Gas plumes drifted NW, then S.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS), CNN

The Washington VAAC reported that on 30 August an ash plume was observed near Reventador by a pilot. Ash was not seen in satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)

RVO reported that during 13-26 August incandescence from Manam's South Crater was visible at night. Main Crater emitted diffuse white vapor. During 27-28 August incandescence emanated from both craters and brightened every 15-20 minutes. At that time, incandescent lava fragments ejected tens to hundreds of meters above South Crater were reported from observers in Bogia, about 23 km SSW. Weak explosions were heard at 15-20 minute intervals. During 28-29 August diffuse white-to-blue vapor emissions from Main Crater were occasionally accompanied by diffuse gray ash plumes. Incandescent lava fragments continued to be ejected. Based on analysis of satellite imagery, the Darwin VAAC reported that on 30 August an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55 km NW.

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash Advisory Centre (VAAC)

KVERT reported that 20-27 August seismic activity from Kliuchevskoi was above background levels and lava flowed down the SW flank. Strombolian activity and gas-and-ash emissions were observed on 20 and 21 August. Cloud cover prevented observations the other days. Satellite imagery analyses showed a large and intense daily thermal anomaly from the volcano and ash plumes that drifted more than 200 km SE on 20 August. Based on analyses of satellite imagery and information from KEMSD, the Tokyo VAAC reported that an eruption on 28 August produced plumes that rose to altitudes of 7.6-10.4 km (25,000-34,000 ft) a.s.l. and drifted SE. Satellite imagery showed a possible eruption on 30 August. The Aviation Color Code level remained at Orange.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)

CVGHM reported that on 28 August Sinabung emitted diffuse white plumes that rose 20 m and showed no signs of increased activity. On 29 August rumbling was heard, prompting authorizes to contact and move people living within a 6-km-radius of the volcano. Later that day, an explosion produced an ash plume that rose 1.5 km above the crater, and the Alert Level was raised to 4 (on a scale of 1-4). Media footage of the eruption at one point showed two closely spaced ash plumes from vents near the summit, causing domestic flights to be diverted. The next day a second, more powerful, explosion generated an ash plume that rose 2 km above the crater. The number of people media sources reported had evacuated ranged from 20,000-30,000. Ash fell in nearby areas and a strong sulfur odor was reported. Nighttime video showed incandescent material descending the flank of the volcano.

Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Associated Press, Daily Mail

The Washington VAAC reported that on 30 August an ash plume was observed near Sangay by a pilot. Ash was not seen in satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)