AVO reported that on 24 December the Volcano Alert Level for Cleveland was raised to Advisory, and the Aviation Color Code was raised to Yellow, due to a persistent thermal anomaly near the summit visible on satellite imagery acquired the day before. The previous Alert Levels were listed as Unassigned. Cloud cover prevented observations during 25-27 December. The thermal anomaly was again detected on 28 December, but was absent the next two days. No current seismic information was available because Cleveland does not have a real-time seismic network.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

KVERT reported that during 23-24 December gas-and-steam plumes from Koryaksky containing a small amount of ash were detected on satellite images. On 24 December observers from the Nalychevo valley reported that a dark plume rose 200-300 m from a fumarolic vent (about 3 km a.s.l.) on the NW flank of Koryaksky and a boom was heard later that night. Ash plumes detected in satellite imagery on 25 December drifted about 200 km NE. On 28 December, KVERT raised the Alert Level to Orange and reported that a Vulcanian eruption was occurring. Ash plumes rose to an altitude of 4 km (13,200 ft) a.s.l. and drifted NW.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

OVPDLF reported that during 22-28 December lava from Piton de la Fournaise continued to issue from an active vent in the N part of Dolomieu crater, beneath "La Soufrière" and about 200 m below the crater rim. Gas plumes often reduced visibility. On 24 December, a small cone formed at the vent and occasionally produced lava fountains. During 27-28 December ten active channels were visible on the inner flanks of the crater. On 29 December, no lava was visible at the cone and lava flows were not apparent. The crater was sometimes filled with bluish gas during 29-30 December.

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

MVO reported that during 19-26 December activity from Soufrière Hills lava dome was characterized by increased lava extrusion, rockfalls, and pyroclastic flows. Lava extrusion on the N, W, and SW sides of the dome continued and incandescence on the dome was visible at night when weather was favorable. Rockfall events increased by 80 percent compared to the previous week. Pyroclastic flows began to enter Tyers Ghaut (NW) on 20 December and likely reached the bottom of the ghaut (ravine) on 21, 23, and 25 December. On 22 December, the Hazard Level was increased to 4 due to the repeated occurrences of pyroclastic flows in the lower part of Tyers Ghaut. On 24 December, a large pyroclastic flow that reached Plymouth (about 5 km W), and possibly the sea, generated an ash plume to an altitude of 3 km (10,000 ft) a.s.l. Large incandescent blocks, deposited by rockfalls and pyroclastic flows, were visible on multiple occasions at night in the upper and middle parts of Tyers Ghaut.

Based on analysis of satellite imagery, the Washington VAAC reported that during 26-30 December ash plumes drifted W, WSW, SW, and S. Intermittent thermal anomalies were detected on satellite imagery on 27 December. Plumes rose to altitudes of 2.1-4.9 km (7,000-16,000 ft) a.s.l. on 28 and 30 December.

Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)

The IG reported that during 23 and 25-29 December ash plumes from Tungurahua rose to altitudes of 6-9 km (19,700-29,500 ft) a.s.l. and drifted mostly S, SW, W, and NW. On 23 December incandescent material rolled down Tungurahua's flanks and a possible pyroclastic flow traveled 700 m down the NW flank. Ashfall was reported and explosions vibrated windows and the ground in areas to the SW. During 24-29 December roaring and "cannon shot" noises were reported almost daily; windows and the ground vibrated on 24, 28, and 30 December. A lahar traveled SW down the Mapayacu ravine on 27 December. Incandescence at the summit and ashfall in areas downwind were noted on 25, 26, 28, and 29 December. Explosions ejected blocks that rolled 500 m down the flanks on 25 December, 1500 m on 29 December, and 800 m on 30 December. On 30 December heavy black ash fell in areas to the SW.

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

Based on analysis of satellite imagery, the Darwin VAAC reported that on 29 December an ash plume from Bagana drifted about 75 km W. On 30 December an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

SERNAGEOMIN reported that, although inclement weather mostly prevented observations of Chaitén during 24-29 December, a gas-and-steam plume was seen on a web camera rising above Domo Nuevo 2 on 25 and 28 December. The plume was brown mainly at the base and rose to an altitude of about 3.1 km (10,200 ft) a.s.l. The Alert Level remained Red.

Based on analysis of satellite imagery and web camera views, the Buenos Aires VAAC reported that during 25-26 and 29 December ash plumes continuously rose to altitudes 2-2.1 km (6,500-7,000 ft) a.s.l. and drifted NNE.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos Aires Volcanic Ash Advisory Center (VAAC)

KVERT reported that on 18 and 20 December seismic activity at Karymsky was at background levels; possible explosions may have generated ash-and-gas plumes to an altitude of 3 km (9,800 ft) a.s.l. on 18 December. Analysis of satellite imagery revealed a thermal anomaly in the crater during 21-26 December and ash plumes that drifted 80 km E during 21-23 December. Ash deposits 26 km long to the SE and 9 km long to the NE were noted on 21 December. The Level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that during 24-30 December lava flowed SE through a tube system from underneath Kīlauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Thermal anomalies were detected on satellite imagery at the base of the pali and on the coastal plain. Explosions at the ocean entry were noted on 26 and 29 December.

Earthquakes were variously located beneath the caldera, along the S-flank fault, and along the SW rift zone. The vent in Halemaʻumaʻu crater continued to produce a predominantly white plume that drifted mainly SW. Following a decreasing trend since 15 December, the vent produced minimal amounts of tephra that mostly consisted of fine rock dust. The sulfur dioxide emission rate at the summit was 400 and 800 tonnes per day on 24 and 29 December, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

KVERT reported that seismic activity at Kliuchevskoi was above background levels during 19-26 December. Gas-and-steam plumes containing ash rose to an altitude of 7 km (23,000 ft) a.s.l. during 20-24 December. Lava effusion on the NW flank continued and Strombolian activity was noted during 21-25 December. Analysis of satellite imagery revealed a large daily thermal anomaly in the crater. Ash plumes drifted 270 km E and NE during 20-25 December.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

RVO reported that during 20-26 December gray ash plumes from Rabaul caldera's Tavurvur cone rose to altitudes of 1.7-2.2 km (5,600-7,200 ft) a.s.l. and drifted SE and W. Ashfall was reported in areas downwind, including Kokopo Town (SE). Rumbling and roaring noises were reported on some days. Explosions or forceful emissions sometimes ejected incandescent lava fragments that fell back into the crater and occasionally onto the slopes.

Based on analysis of satellite imagery and pilot observations, the Darwin VAAC reported that on 30 December an ash plume rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted N and NW.

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

Based on analysis of satellite imagery, the Washington VAAC reported that a small ash plume from Santa María's Santiaguito lava dome complex drifted NW on 23 December. The next day a plume drifted W, and on 25 December a puff of ash drifted WNW.

Source: Washington Volcanic Ash Advisory Center (VAAC)

KVERT reported that seismic activity at Shiveluch was above background levels during 19-26 December. Based on interpretations of seismic data, ash plumes rose to an altitude of 8.5 km (27,800 ft) a.s.l. on 19 and 20 December and to an altitude of 5 km (16,400 ft) a.s.l. during 21-26 December. An ash plume was seen on 22 December at an altitude of 5 km (16,400 ft) a.s.l. and gas-and-steam emissions were noted on 23 and 24 December. Analysis of satellite imagery revealed a daily thermal anomaly on the lava dome. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD and analysis of satellite imagery, the Tokyo VAAC reported that during 26-27 and 30 December eruptions produced plumes to altitudes of 5.5-7 km (18,000-23,000 ft) a.s.l.

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

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 26-28 and 30 December. Plumes rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. during 27-28 December.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)