Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week 29 November - 6 December 2022

Aira - Kyushu (Japan) : JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) consisting of a few eruptive events and two explosions. Crater incandescence was visible nightly, sometimes characterized as incandescent flashes. An explosion at 0340 on 2 December produced an ash plume that rose as high as 3.2 km above the crater rim and ejected large blocks as far as 1.1 km from the vent. The second explosion, recorded at 1929 on 3 December, produced an ash plume that rose as high as 3 km and ejected large blocks 1-1.3 km away. Webcam video of the event showed incandescent material ejected above the crater and lightning in the ash plume.

Alaid - Kuril Islands (Russia) : KVERT reported that the eruption at Alaid was ongoing during 25 November-1 December. A daily thermal anomaly was identified in satellite images. Ash plumes drifted 220 km SE during 25-26 November.

Dukono - Halmahera : PVMBG reported that almost daily white-and-gray plumes from Dukono rose as high as 450 m above the summit and drifted NE, E, S, and SW during 30 November-6 December. Inclement weather conditions sometimes prevented visual observations.

Ebeko - Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 24 November-1 December. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions on 26 November and 1 December generated ash plumes that rose to 2.7 km (8,900 ft) a.s.l. and drifted NE. Ash fell in Severo-Kurilsk on 16 November. A thermal anomaly was identified in satellite images on 30 November; weather clouds prevented satellite views on the other days of the week.

Fuego - South-Central Guatemala : INSIVUMEH reported that 4-12 explosions per hour were recorded at Fuego during 29 November-6 December, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km W, WSW, and SW causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Los Yucales (12 km SW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), Finca Palo Verde, Ojo de Agua, and Santa Emilia. Daily shock waves rattled structures in communities around the volcano. Daily block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, Las Lajas (SE), El Jute (ESE), and Trinity drainages, often reaching vegetated areas. Strombolian explosions ejected incandescent material as high as 400 m above the summit on a few of the days.

Great Sitkin - Andreanof Islands (USA) : AVO reported that slow lava effusion continued at Great Sitkin during 30 Novmeber-6 December. Lobes of lava advanced an additional 25-30 m along the S edge of the flow field and about 15 m SE, based on 25 November satellite images. Cloud cover prevented satellite and webcam observations during 30 Novmeber-6 December. Seismicity remained at low levels.

Kerinci - Central Sumatra : PVMBG reported that white steam-and-gas plumes rose as high as 300 m above Kerinci’s summit and drifted E almost daily during 29 November-5 December. Gray and white-to-brown plumes rose 100-300 m above the summit during 1-3 December. At 0822 on 6 December a gray-to-black ash plume rose about 700 m above the summit and drifted SW.

Kilauea - Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 30 November-6 December entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level most of the week, fluctuating only a few meters during 4-6 December.

Late - Tonga Ridge : On 29 November Tonga Geological Services reported results from a recent visit to Late. The observers noted warmed ground surfaces, steam rising from fresh cracks, and vents at the summit. The features were too small to be identified in satellite images processed by VOLCAT (Volcanic Cloud Analysis Toolkit) software. They concluded that the features were the result of low-temperature hydrothermal activity driven by a shallow magma body at depth, and that the cracks were the result of past volcanic activity. There were no risks to local communities and mariners were advised to report any observable changes to the island.

Machin - Colombia : On 2 December SGC reported that an increase in seismicity was detected at Cerro Machín beginning at 1123 on 2 December, with signals indicating rock fracturing. By 1320 a total of 393 signal were counted. The largest event, a M 4.5 recorded at 1236, was located 900 m SSW of the main dome at a depth of 3 km and was felt in Cajamarca (14 km WSW), Ibagué (17 km ESE), and in other municipalities of Tolima.

Merapi - Central Java : BPPTKG reported that the eruption at Merapi continued during 25 November-1 December and seismicity remained at high levels. The SW lava dome produced five lava avalanches that traveled as far as 1.5 km down the SW flank (upstream in the Kali Bebeng drainage). No significant morphological changes to the central and SW lava domes were evident.

Nevado del Ruiz - Colombia : Servicio Geológico Colombiano’s (SGC) reported that increased seismicity at Nevado del Ruiz began to be recorded at around 1016 on 2 December and increased further on 3 December. The signals indicated moving fluids within the volcano’s conduit and were associated with gas-and-ash emissions seen from several municipalities in Tolima and Caldas. The gas-and-ash plumes generally rose less than 900 m above the summit and drifted SW but occasionally rose as high as 2.9 km.

Pavlof - Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 29 November-6 December and nearly continuous seismic tremor was recorded. Daily small explosions were recorded through 3 December. Elevated surface temperatures were identified in satellite and webcam images during 29 November-1 December; weather clouds often prevented views during most of the week. A small plume was visible during 5-6 December; the ash content was unknown.

Reventador - Ecuador : IG described the ongoing eruption at Reventador as moderate during 29 November-6 December. Daily seismicity was characterized by explosions, long-period earthquakes, periods of harmonic tremor, and signals that indicated emissions. Gas, steam, and ash plumes, observed almost daily with webcams or reported by the Washington VAAC, rose as high as 1.9 km above the summit and drifted in multiple directions. Weather clouds occasionally prevented webcam and satellite views of the volcano. Active lava flows on the N and NE flanks were periodically visible in webcam views.

Santa Maria - Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 29 November-6 December. Effusion from Caliente cone fed lava flows that descended the San Isidro and El Tambor drainages on the W and SW flanks. Occasional block avalanches from the dome, and from both the ends and sides of the flows, descended the S, SW, and W flanks. The avalanches sometimes generated minor ash plumes that rose along their paths. Almost daily explosions produced gas-and-steam plumes with minor amounts of ash that rose as high as 800 m above the complex and sometimes drifted 5-8 km SW.

Sheveluch - Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch during 24 November-1 December was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A daily thermal anomaly was identified in satellite images. Collapses generated hot avalanches and ash plumes that drifted 90 km NE on 26 and 29 November, and 1 December.

Stromboli - Aeolian Islands (Italy) : INGV reported that starting at 1510 on 4 December lava overflowed Stromboli’s Area N (North Crater area) in conjunction with intense explosive activity. A strong explosion occurred at Area C-S (South-Central Crater area) at 1516, and at 1528 small collapses began shedding material onto the upper parts of the Sciara del Fuoco. At 1531 lava overflows and explosive activity likely collapsed part of a crater rim in Area N, resulting in pyroclastic flows that descended the Sciara del Fuoco. At 1619 a large pyroclastic flow descended the Sciara del Fuoco for several minutes and generated abundant ash clouds that temporarily blocked the view of the summit area. The pyroclastic flow went some distance over the water and caused a small tsunami. A lava flow was visible on the Sciara del Fuoco at 1640, and by about 1700 it had reached the coast. The lava flow originated from a fissure located just downslope of the N2 vent in the Area N. Abundant amounts of reddish-colored tephra fell in Ginostra, 1.5 km SW of summit. The Dipartimento della Protezione Civile raised the Alert Level to Orange (the second highest level on a four-color scale). Explosive activity continued at Area N. Lava effused from the vent at variable rates during 5-6 December, with higher rates corresponding to more intense explosive activity. Beginning at about 0830 on 5 December most explosions occurred at N2, with coarse material ejected a few tens of meters above the vent. Boulders rolled down the Sciara del Fuoco and caused diffuse ash plumes that quickly dispersed. Explosions at the summit were generally infrequent.

Suwanosejima - Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 28 November-5 December and crater incandescence was visible nightly. No explosions were recorded. Eruption plumes rose as high as 1.8 km above the crater rim and blocks were ejected as far as 300 m from the vent. Ashfall was occasionally reported in Toshima village (3.5 km SSW).