On 27 November, INGEOMINAS lowered the Alert Level for Galeras to III (Yellow; "changes in the behavior of volcanic activity"). During the previous few days, seismicity was low and occasionally punctuated by signals indicative of minor gas and ash emissions. An overflight on 26 November revealed gas emissions from the interior walls of the main crater and thermal anomalies with temperatures of 200 degrees Celsius. During 27 November-1 December, seismicity remained low; signals indicated gas emissions.

Source: Servicio Geológico Colombiano (SGC)

The Vanuatu Geohazards Observatory reported that a large explosion from Gaua's Mount Garat on 18 November was followed by high dense ash plumes. Seismicity increased on 25 October and remained significant through 24 November. According to news articles, an explosion that caused ashfall in inhabited areas on 26 November prompted the evacuation of more than 300 people. The Alert Level was raised to 4, the second highest level on a scale of 0-5.

Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Agence France-Presse (AFP)

Based on analyses of satellite imagery, the Darwin VAAC reported that an eruption from Karkar on 25 November produced a plume that rose to an altitude of 13.7 km (45,000 ft) a.s.l. The report also stated that ash had merged with a thunderstorm cloud and had become unidentifiable. Another ash plume identified on 26 November rose to an altitude of 9.1 km (30,000 ft) a.s.l. Confirmation of ash emissions was not available from RVO at the time of the posting of this report. [Note: Further analyses revealed that an eruption had not occurred. Additional information received by RVO indicated dead vegetation S of the active crater (similar observations were made in 2007) and a few new "holes" in the crater area.]

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

SVERT reported that a thermal anomaly on Sarychev Peak was detected by satellite on 25 November. Steam-and-gas emissions were noted on 25, 26, and 29 November.

Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima on 26 November and 1 December produced plumes that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted SW and E. Ash was seen in satellite imagery on 26 November.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Based on analyses of satellite imagery, the Buenos Aires VAAC reported that on 26 November a diffuse plume from Chaitén's lava-dome complex drifted ENE.

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

The Darwin VAAC reported that on 30 November an ash plume from Dukono at an altitude of 3 km (10,000 ft) a.s.l. was observed on satellite imagery 75 km E.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Based on analyses of satellite imagery, the Washington VAAC reported that on 29 November a small plume from Fuego, possibly containing ash, drifted 10 km SW. A thermal anomaly was also detected. On 30 November and 1 December, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 4.3-4.7 km (14,100-15,400 ft) a.s.l. and drifted 8-15 km W and SW. Rumbling noises were noted and incandescent block avalanches were generated.

Sources: Washington Volcanic Ash Advisory Center (VAAC), Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

KVERT reported that seismic activity at Karymsky was above background levels on 23 and 25 November; data were not available on the other days during 20-27 November due to technical reasons. Elevated seismicity possibly indicated that ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. Analyses of satellite imagery revealed a daily thermal anomaly and ash plumes that drifted 120 km E on 23 and 25 November. The Level of Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

During 25 November-1 December, HVO reported that lava flowed SE from beneath Kīlauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. A small bench collapse may have occurred on 27 November. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows on the coastal plain. Incandescence was occasionally seen on the Puʻu ʻŌʻō crater floor.

The vent in Halemaʻumaʻu crater continued to produce a white or off-white plume that drifted mainly SW and dropped small amounts of ash downwind. Incandescence originated from a lava pond deep in the vent cavity floor; the lava pond circulated and spattered during 25-26 November and 1 December. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 1,000 tonnes per day were measured on 28 and 30 November. The 2003-2007 average rate was 140 tonnes per day.

According to a news article on 30 November, Hawaii county was declared a natural disaster area due to the negative impact that vog from Halemaʻumaʻu crater has had on croplands and livestock.

Sources: Hawaii News Now, US Geological Survey Hawaiian Volcano Observatory (HVO)

KVERT reported that during 20-27 November seismic activity from Kliuchevskoi was above background levels and lava continued to flow down the ESE flank. Strombolian activity ejected tephra 300 m above the crater during 21-25 November. Satellite imagery revealed a large daily thermal anomaly at the volcano. The Level of Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

INGEOMINAS reported that during 25 November-1 December gas plumes from Nevado del Huila were seen on the web camera rising 8.4 km (27,600 ft) a.s.l. and drifting downwind. Seismicity included both tremor indicative of gas emissions and hybrid earthquakes. An overflight on 25 November revealed that the newest lava dome had continued to grow. Based on pilot observations, the Washington VAAC reported that on 26 November a gas plume, possibly containing ash, rose to an altitude of 7.6 km (25,000 ft) a.s.l. Ash was not identified in satellite imagery, although low weather clouds were present in the area. A sulfur dioxide plume was emitted on 30 November at a calculated rate of 3,900 tons per day. The Alert Level remained at II (Orange; "probable eruption in term of days or weeks").

Sources: Washington Volcanic Ash Advisory Center (VAAC), Servicio Geológico Colombiano (SGC)

RVO reported that during 20-26 November thick white plumes and gray ash plumes rose from Rabaul caldera's Tavurvur cone. Strong explosions produced ash plumes that rose 1.5 km above the summit and showered the flanks with lava fragments that were incandescent at night. Shock waves rattled windows in the Kokopo area, about 20 km SE. Occasionally, incandescence from the summit crater was noted.

Source: Rabaul Volcano Observatory (RVO)

Based on a pilot observation, the Washington VAAC reported that on 1 December an ash plume from Sangay rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted W. Ash was not identified in satellite imagery, although low weather clouds were present in the area. Later that day, an eruption was reported, but ash was again unidentifiable in satellite imagery.

Source: Washington Volcanic Ash Advisory Center (VAAC)

KVERT reported that during 20-27 November seismic activity from Shiveluch was above background levels, possibly indicating that ash plumes rose to an altitude of 4.3 km (14,100 ft) a.s.l. Fumarolic activity was seen using a video camera. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome. The Level of Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

MVO reported that during 20-27 November activity from the Soufrière Hills lava dome continued at a high level. Activity increased on 21 November and periods of tremor were detected on 23 November. Lava extrusion during this period shifted from the W side of the lava dome to the summit region. As a result, abundant pyroclastic flows traveled NE down Tuitt's Ghaut on 23 November for the first time in several weeks. On 24 November there was a period of 120 minutes of continuous pyroclastic flow activity, followed by 90 minutes of semi-continuous activity. The pyroclastic flows traveled W down Gages Valley and into Spring Ghaut, and NE down Tuitt's Ghaut and Whites Bottom Ghaut reaching Tuitt's village. Associated ash plumes rose to an altitude of 6.1 km (20,000 ft) a.s.l. On 26 November, a pyroclastic flow that descended the Tar River valley was caused by collapse of part of the old, pre-2009 lava dome. Ashfall occurred in Old Towne and parts of Olveston. Incandescent material seen in a photograph taken at night on 29 November traveled down the flanks of the lava dome in several areas. The Hazard Level remained at 3.

Source: Montserrat Volcano Observatory (MVO)

The Tokyo VAAC reported that on 26 November an ash plume from Suwanose-jima was seen by a pilot 65 km S drifting NE at an altitude of 3 km (10,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)