Based on information from JMA, the Tokyo VAAC reported that on 10 and 11 August eruption plumes from Asama rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE and S, respectively.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Based on observations of satellite imagery, KVERT reported that a thermal anomaly detected over Bezymianny's lava dome grew in area and intensified during 9-11 August. Based on interpretations of seismic data, four hot avalanches occurred on 10 August and nine occurred on 11 August. On 12 August, the level of Concern Color Code was raised to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

On 6 August, AVO raised the Volcano Alert Level for Kasatochi to Advisory and the Aviation Color Code to Yellow based on increased seismicity detected that day by instruments in the area and by field crews on the island the previous few days. Kasatochi lacks dedicated seismometers and is monitored by neighboring networks.

On 7 August, earthquake activity continued; events as large as M 5.6 were detected. Crews reported rockfalls, ground shaking lasting 5-10 minutes, and a strong sulfur smell. Periods of volcanic tremor prompted AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. Later that day, an ash plume at an altitude of at least 10.7 km (35,000 ft) a.s.l. was detected on satellite imagery drifting SSW. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. Reports from a marine vessel in the area indicated ashfall and tephra up to pebble size, spectacular lightning, and total darkness for a little over 2 hours. Three major explosive eruptions produced ash plumes that rose to an altitude of 13.7 km (45,000 ft) a.s.l.

Ash emissions became continuous on 8 August following the last explosive event; an ash plume drifted for more than 950 km in a counterclockwise spiral at altitudes of about 9.1-13.7 km (30,000-45,000 ft) a.s.l. Seismicity decreased, although remained elevated, and ash emissions became less frequent. During 8-9 August, seismicity decreased to a level undetectable by stations on Great Sitkin, about 40 km W. On 9 August ash plumes were detected on satellite imagery early in the day; clouds prevented views during the rest of the day. The Volcano Alert Level was lowered to Watch and the Aviation Color Code to Orange. The ash plume from the third eruption on 7 August was seen on satellite imagery 1,850 km ESE of the volcano and was elongated NE-SW over 1,200 km.

According to news articles, flights from Alaska to several west coast cities were cancelled on 10 and 11 August. During 10-12 August, AVO reported that seismicity remained low, but detectable by the network on Great Sitkin.

Sources: The Seattle Times Company, US Geological Survey Alaska Volcano Observatory (AVO)

KVERT reported that seismic activity at Kliuchevskoi had slowly increased since June and was slightly above background levels during 1-8 August. Observations of satellite imagery revealed that the size and intensity of a thermal anomaly in the crater increased. On 8 August, the level of Concern Color Code was raised to Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

On 10 August, a mild explosion from Mayon produced an ash plume to an altitude of 2.7 km (8,900 ft) a.s.l. and drifted ENE. PHIVOLCS reported that during the previous few weeks seismic activity had increased slightly and incandescence at the crater had intensified. The Alert Level remained at 1. The 7-km Extended Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone (PDZ) in all other areas remained in effect.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Based on information from JMA, the Tokyo VAAC reported that on 10 August an eruption plume from Sakura-jima rose to an altitude greater than 2.7 km (9,000 ft) a.s.l. and drifted NW.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

During 7-8 August, small sulfur dioxide plumes from Anatahan were visible on satellite imagery. On 8 August, seismicity decreased significantly. During 8-9 August, steam plumes with small amounts of ash rose to an altitude of 1.8 km (6,000 ft) a.s.l. On 12 August, the Volcanic Alert Level was lowered to Advisory and the Aviation Color Code to Yellow.

Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program

Based on a pilot report and observations of satellite imagery, the Darwin VAAC reported that during 6-8 and 10-11 August ash plumes from Batu Tara rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W and NW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Based on web camera views, SIGMET reports, observations of satellite imagery, and information from the Puerto Montt Flight Information Region (FIR), the Buenos Aires VAAC reported that during 7-8 August ash plumes from Chaitén rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E and NE.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Based on observations of satellite imagery, KVERT reported that eruptive activity from Chikurachki continued during 1-8 August. Ash plumes drifted more than 60 km SE, W, and N during 1-3 August. The level of seismicity was unknown because Chikurachki lacks dedicated seismic instruments. The Level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

On 6 August, AVO reported that the thermal anomalies noted at Cleveland's summit and on the W, S, and SE flanks had decreased in intensity since first noted on 21 July, indicating that the lava flows slowed or stopped. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code to Yellow. During 7-10 August, a weak thermal anomaly at the summit was intermittently visible when not obscured by clouds and drifting ash from the eruption of Kasatochi (about 400 km WSW). On 11 August, thermal anomalies on satellite imagery indicated that lava flowed down the flanks. The Volcano Alert Level was raised to Watch and the Aviation Color Code to Orange. On 12 August, an ash plume rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted 100 km SW.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

KVERT reported that seismic activity at Karymsky was above background levels during 1-8 August and possibly indicated that explosions produced ash plumes to an altitude of 3.1 km (10,200 ft) a.s.l. Observations of satellite imagery revealed a thermal anomaly in the crater on 2 August; clouds inhibited views on other days. The Level of Concern Color Code remained at Orange.

Based on observations of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 11 August an eruption plume rose to an altitude of 3.4 km (11,000 ft) a.s.l.

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

HVO reported that during 6 and 9-12 August lava flowed SE through a lava tube system from underneath Kīlauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Occasional explosions and surface lava flows were noted near the ocean entry. A small fountain in a lava pond at the top of one of the rootless shields was observed on 10 August. The sulfur dioxide emission rate at Puʻu ʻŌʻō was 1,700 and 2,400 tonnes per day on 8 and 9 August, respectively; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kīlauea earthquakes were variously located beneath Halemaʻumaʻu crater, along the Koa'e fault system, SE and W of the caldera, along the S-flank faults, and along the E and SW rift zones. Beneath Halemaʻumaʻu crater, up to 100 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halemaʻumaʻu crater continued to produce a mainly white plume with minor ash content that drifted SW. The plume was occasionally tinged brown. Night-time incandescence was seen at the base of the plume rock-clattering sounds were heard in the vicinity of the crater. The sulfur dioxide emission rate was high at 900 tonnes per day on 7 August. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

According to a news article, eruptions from Anak Krakatau increased in frequency during 10-11 August. On 12 August, monitoring personnel reported that active lava flows and emissions of thick "smoke" continued but that the frequency of earthquakes and eruptions had declined.

Source: Antara News

AVO scientists observed the eruption of Okmok during a visit to Umnak Island on 2 and 3 August. They saw significant ashfall that had accumulated in the caldera and on the upper flanks, lahars and lahar deltas that formed in drainages from the SE to the NE flank, and continuous ash jets being emitted from three or more vents in the vicinity of Cone D in the NE sector of the caldera. Elevated seismicity was detected during 6-8 August, and declined on 9 August. According to observations of satellite imagery, steam plumes possibly containing ash rose to altitudes below 4.6 km (15,000 ft) a.s.l. during 9-10 August. On 11 August, steam plumes rose to altitudes of less than 6.1 km (20,000 ft) a.s.l. and drifted SE. Ash plumes that rose to around a hundred meters above the crater were reported by an observer in Nikolski (80 km SW). These plumes were not detected on satellite imagery due to cloud cover. On 12 August, a pilot reported an ash plume at an altitude of 4.6 km (15,000 ft) a.s.l. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

OVPDLF reported that a small seismic crisis beneath the summit of Piton de la Fournaise lasted about 10 minutes on 4 August. The strongest earthquake was a M 1.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

RVO reported that ash plumes from Rabaul caldera's Tavurvur cone continued to be emitted during 4-10 August. Ashfall was reported in areas NW. Occasionally incandescence at the summit was observed and roaring noises were reported. Incandescent lava fragments were ejected along with some of the more forceful ash emissions. Based on observations of satellite imagery and information from RVO, the Darwin VAAC reported that during 11-12 August, low-level ash plumes rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted NW.

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

The IG reported that steam-and-gas from Reventador was emitted during 6-8 August. Incandescence from the crater was observed at night on 8 August.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Based on information from CVGHM, the Darwin VAAC reported that on 7 August ash plumes from Semeru rose to an altitude of 4.3 km (14,100 ft) a.s.l. and that incandescent material was ejected from the crater. CVGHM indicated that the activity was normal; the Alert Level remained at 2 (on a scale of 1-4).

Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

KVERT reported that seismic activity at Shiveluch was slightly above background levels during 1-8 August, and possibly indicated that ash plumes from explosions rose to an altitude of 4.6 km (15,100 ft) a.s.l. on 6 August. Observations of satellite imagery revealed a thermal anomaly on the lava dome during 1-3 August. The Level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

MVO reported that seismic levels from Soufrière Hills were relatively low during 1-8 August. Sulfur dioxide emissions (tons per day) were significantly higher than emissions prior to the partial lava-dome collapse on 28 July. Unconfirmed reports indicated the presence of an ash plume on 3 August. A small ash cloud was seen on 7 August.

Further investigation of the 28 July event revealed that the total amount of material that collapsed from the dome was about 200,000-300,000 cubic meters. Satellite radar images indicated that the vent above Gages wall was enlarged by the explosion to about 150 x 60 meters, elongated E-W. Precautionary access restrictions for areas in and around Belham valley were lifted because evidence suggested that the dome had not been destabilized due to the event.

A new Hazard Level System, designed by MVO and Disaster Management Coordination Agency (DMCA) in consultation with the Government of Montserrat and community groups, was implemented on 8 August. The system divides the southern two-thirds of the island into six zones, and includes two Maritime Exclusion Zones. The Hazard Level ranges from 1-5 and is set by the National Disaster Preparedness, Response, and Advisory Committee (NDPRAC) with advice from MVO. The Hazard Level restricts access into each of the zones depending on the number assigned and is unrelated to the Alert Level. The current Hazard Level was 3.

Source: Montserrat Volcano Observatory (MVO)

Based on reports from JMA, the Tokyo VAAC reported that on 7 August an eruption plume from Suwanose-jima rose to an altitude of 1.2 km (4,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

The IG reported that during 6-8 August, explosions from Tungurahua were detected by the seismic network. Although clouds mostly prevented visual observations, steam-and-ash plumes were observed; on 6 August, ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted W. Ashfall was reported in areas to the SW.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)