Smithsonian / USGS Weekly Volcanic Activity Report

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday and averaging 16 reported volcanoes, this is not a comprehensive list of all eruptions this week, but rather a summary of activity that meet criteria discussed in the "Criteria and Disclaimers" section below.

Volcanic activity reported here is preliminary and subject to change. Carefully reviewed, detailed narratives over longer time periods are published as reports of the Bulletin of the Global Volcanism Network available through volcano profile pages.

Smithsonian / USGS Weekly Volcanic Activity Report for the week of 7 December-13 December 2022
Name	Location	Eruption Start Date	Report Status
Ahyi	Mariana Islands (USA)	2024 Jan 1	New
Fuego	South-Central Guatemala	2002 Jan 4	New
Lascar	Northern Chile	—	New
Mauna Loa	Hawaiian Islands (USA)	—	New
Semeru	Eastern Java	2017 Jun 6	New
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Alaid	Kuril Islands (Russia)	—	Continuing
Cotopaxi	Ecuador	—	Continuing
Ebeko	Paramushir Island (Russia)	2022 Jun 11	Continuing
Great Sitkin	Andreanof Islands (USA)	2021 May 25	Continuing
Kilauea	Hawaiian Islands (USA)	—	Continuing
Merapi	Central Java	2020 Dec 31	Continuing
Pavlof	Alaska Peninsula, Alaska	—	Continuing
Sabancaya	Peru	2016 Nov 6	Continuing
San Miguel	Eastern El Salvador	—	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Stromboli	Aeolian Islands (Italy)	1934 Feb 2	Continuing
Suwanosejima	Ryukyu Islands (Japan)	2004 Oct 23	Continuing
Villarrica	Central Chile	2014 Dec 2 ± 7 days	Continuing
Whakaari/White Island	North Island (New Zealand)	—	Continuing

All times are local unless otherwise stated.

Ahyi | 7 December-13 December 2022 | New Activity / Unrest Cite this Report

Ahyi
Mariana Islands (USA)

Unrest continued to be detected at Ahyi Seamount during 7-13 December. Wake Island hydrophone sensors detected daily signals consistent with explosions during 10-12 December. No signs of underwater plumes were visible in satellite images during 10-11 December; weather clouds obscured the area on 12 December. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).

Source: US Geological Survey

Fuego | 7 December-13 December 2022 | New Activity / Unrest Cite this Report

Fuego
South-Central Guatemala

INSIVUMEH reported that the eruption at Fuego was ongoing during 7-13 December, though activity had notably intensified during 10-11 December. The seismic network recorded 4-10 explosions per hour during the week, with ash plumes rising as high as 1.2 km above the crater rim. The ash plumes generally drifted 10-20 km NW, W, 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), Finca Palo Verde, Sangre de Cristo (8 km WSW), San Pedro Yepocapa (8 km NW). 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), and El Jute (ESE) drainages, often reaching vegetated areas. Strombolian explosions ejected incandescent material as high as 200 m above the summit on a few of the days.

Activity increased on 10 December. In a special report posted at 2241, INSIVUMEH noted that in the previous minutes multiple explosions of variable intensities produced ash plume that rose 1.2 km above the summit and drifted 30 km W and NW. Pulsating lava fountains rose as high as 500 m above the summit. A lava flow had traveled 800 m down the Ceniza drainage by the time the report was issued, and avalanches of material spalled from its front reached vegetated areas. At 2300 pyroclastic flows descended the Las Lajas drainage several kilometers. Dense ash plumes and pyroclastic flows down the Las Lajas drainage continued for at least an hour. Just before 0030 on 11 December pyroclastic flows traveled several kilometers down the Ceniza drainage on the SW flank. Lava fountains rose as high as 300 m. By 0640 dense ash plumes were rising over 1.2 km above the summit and the lava flow remained active. Avalanches of material from the advancing lava front descended to vegetated areas. Satellite images showed that ash clouds had spread NE, E, and SE, covering a wide area in the department of Sacatepéquez and the central and southern parts of the department of Guatemala. Activity decreased by the early afternoon; lava fountaining, dense ash emissions, and pyroclastic flows had all ceased before 1410.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Lascar | 7 December-13 December 2022 | New Activity / Unrest Cite this Report

Lascar
Northern Chile

SERNAGEOMIN reported that an eruption at Láscar began at 1236 on 10 December with an explosive event that produced a dense ash plume and pyroclastic flows proximal to the crater. Hikers were near the crater and took video of the eruption. According to SEGEMAR the pyroclastic flows traveled short distances to the N and SE. The ash plume rose about 6 km above the crater rim and drifted SW. The event was coincident with a long-period earthquake detected by the seismic network. Later that day the Alert Level was raised to Yellow (the second lowest level on a four-color scale) and the public were warned to stay at least 5 km away from the crater. ONEMI declared an Alert Level Yellow (the middle level on a three-color scale) for San Pedro de Atacama (70 km NW). CKELAR noted that the thermal anomaly had intensified during the five days prior to the eruption along with increased sulfur dioxide gas emissions.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Servicio Geológico Minero Argentino (SEGEMAR), Instituto Milenio de Investigación en Riesgo Volcánico (CKELAR), Red Geocientífica de Chile

Mauna Loa | 7 December-13 December 2022 | New Activity / Unrest Cite this Report

Mauna Loa
Hawaiian Islands (USA)

HVO reported that activity at Mauna Loa’s Fissure 3 declined during 7-9 December and then ceased on 10 December. The main lava flow had only advanced a small distance during 6-7 December, at a rate of about 6 m per hour, possibly due to a significant breakout that had occurred about 4.5 km upslope of the flow front. Lava erupting from Fissure 3 was greatly reduced by the morning of 8 December. Lava overtopped channels near the vent but had not advanced farther than 4.4 km from the vent by 0930. The channel at lower elevations appeared to be drained and was likely no longer feeding the main flow which had stalled about 2.8 km from the Daniel K. Inouye Highway (Saddle Road). The sulfur dioxide emission rate had declined to 30,000 tonnes per day. By 1130 on 9 December low lava fountains at Fissure 3 fed flows that traveled as far as 2.65 km NE. By 0700 on 10 December a lava pond in the Fissure 3 vent was visible and fed short lava flows that stagnated at 2.6 km. Tremor levels were slowly declining and the sulfur dioxide emission rate was about 2,000 tonnnes per day. Lava was confined to the small pond by 1435 and gas emissions had significantly declined. HVO lowered the Volcano Alert Level to Watch (the second highest level on a four-level scale); the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

No activity was visible on the flow field overnight during 10-11 December, and by 0700 on 11 December the Fissure 3 vent was barely incandescent. Scientists observed no lava movement and only minor incandescence at the vent during an overflight in the early morning of 12 December. They heard a small explosion that accompanied a spray of spatter from the W end of the fissure. On 13 December HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Yellow and noted that lava effusion at Fissure 3 had ceased on 10 December, sulfur dioxide emissions had decreased to near pre-eruption background levels, and volcanic tremor and earthquakes associated with the eruption were greatly diminished.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Semeru | 7 December-13 December 2022 | New Activity / Unrest Cite this Report

Semeru
Eastern Java

BNPB reported that residents continued to be impacted by the collapses and large pyroclastic flows on Semeru’s SE flank on 4 December. As of 6 December, there were 781 people spread across 21 evacuation shelters and heavy ashfall prevented aid from easily reaching Pronojiwo Village, according to BNPB. Kajar Kuning was the worst affected village.

PVMBG reported that lava continued to erupt from the summit vent during 4-9 December, though activity generally declined. Ongoing thermal anomalies were identified in satellite images, though the intensity had decreased. The rate of deformation had declined based on tiltmeter data. Four pyroclastic flows moved as far as 6 km down the SE flanks, and avalanches of material traveled 300-500 m SE. At 0521 on 8 December a gray-to-white ash plume rose around 300 m above the summit and drifted N. At 0536 a gray ash plume rose 400 m and drifted N, as reported by a ground-based observer. A dense gray ash plume rose 500 m and drifted N at 0521 on 9 December. Later that day, at 1200, the Alert Level was lowered to 3 (the second highest level on a scale of 1-4) and the public was warned to stay at least 5 km away from the summit, as far as 13 km from the summer on the SE flanks, and 500 m from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Eruptive activity continued during 10-13 December. At 0653 on 10 December a dense white-to-gray ash plume rose about 700 m above the summit and drifted N. White-and-gray ash plume were visible at 0652 on 11 December and 0727 on 12 December rising at least 500 m and drifting S and SW, respectively.

Sources: Badan Nacional Penanggulangan Bencana (BNPB), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Aira | 7 December-13 December 2022 | Continuing ActivityCite this Report

Aira
Kyushu (Japan)

JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 5-12 December consisting of a few eruptive events and three explosions. Crater incandescence was visible nightly. Explosions produced ash plumes that rose as high as 2.7 km above the crater rim and ejected large blocks as far as 1.1 km away. Sulfur dioxide emissions were high at 2,800 tons per day on 6 December. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Alaid | 7 December-13 December 2022 | Continuing ActivityCite this Report

Alaid
Kuril Islands (Russia)

KVERT reported that the eruption at Alaid was ongoing during 1-8 December. A thermal anomaly was identified in satellite images on 2 and 8 December; weather clouds obscured observations on the other days. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Cotopaxi | 7 December-13 December 2022 | Continuing ActivityCite this Report

Cotopaxi
Ecuador

IG reported that the low-level eruption at Cotopaxi continued during 7-13 December characterized by steam-and-gas emissions and occasional ash emissions. Sulfur dioxide emissions measured by satellite almost daily averaged 665-2,745 tons per day. Steam-and-gas emissions observed during 7-10 December rose as high as 2 km above the crater rim and drifted SW, W, and NW. Ash emissions during 0758-0816 on 8 December rose 1 km and drifted WNW. The Washington VAAC issued three advisories noting that ash rose 800-1,100 m and drifted W. A tremor signal that started at 0832 on 9 December was probably related to gas-and-ash emissions, though cloudy weather conditions prevented visual confirmation. During the night of 9-10 December several steam-and-ash emissions were identified in satellite images rising as high as 1.1 km and drifting NW. Minor ashfall was reported in Conocoto-Pichincha in the morning of 10 December. At 0930 on 11 December the seismic stations recorded a signal related to gas-and-ash emissions that rose 2 km and drifted W. Ash fell in Control Caspi, located at the S entrance to Parque Nacional Cotopaxi. Several gas-and-steam emissions with low ash content were visible that afternoon and during the morning of 12 December rising as high as 500 m and drifting W. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)

Ebeko | 7 December-13 December 2022 | Continuing ActivityCite this Report

Ebeko
Paramushir Island (Russia)

KVERT reported that moderate activity at Ebeko was ongoing during 1-8 December. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 1-2 and 7 December generated ash plumes that rose to 2.5 km (8,200 ft) a.s.l. and drifted NE. The volcano was quiet or obscured by weather clouds on the other days of the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Great Sitkin | 7 December-13 December 2022 | Continuing ActivityCite this Report

Great Sitkin
Andreanof Islands (USA)

AVO reported that slow lava effusion continued at Great Sitkin during 27 November-11 December based on satellite images. Cloud cover mostly prevented satellite and webcam observations during 7-12 December. Seismicity remained at low levels. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Kilauea | 7 December-13 December 2022 | Continuing ActivityCite this Report

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 6-8 December and entered the lava lake, though the eruption rate had diminished, and the floor of the crater had deflated. The eruption ceased on 9 December. During 10-12 December the lake crusted over, no incandescence was visible, and sulfur dioxide emissions had decreased to near pre-eruption background levels. On 13 December HVO lowered the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code to Yellow (the second lowest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Merapi | 7 December-13 December 2022 | Continuing ActivityCite this Report

Merapi
Central Java

BPPTKG reported that the eruption at Merapi continued during 2-8 December and seismicity remained at high levels. The SW lava dome produced two lava avalanches that traveled as far as 1.6 km down the SW flank (upstream in the Kali Bebeng drainage). No significant morphological changes to the central and SW lava domes were evident. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location.

Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)

Pavlof | 7 December-13 December 2022 | Continuing ActivityCite this Report

Pavlof
Alaska Peninsula, Alaska

AVO reported that seismic tremor and a few low-frequency earthquakes at Pavlof indicated continuing unrest during 7-13 December; one explosion was recorded on 7 December. No explosions or lava flow activity was detected in seismic, infrasound, satellite, or webcam data during the rest of the week. The report noted that events on 3 December resulted in the erosion of a narrow, 2-km-long gully beneath the ice below the vent. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sabancaya | 7 December-13 December 2022 | Continuing ActivityCite this Report

Sabancaya
Peru

Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 December with a daily average of 40 explosions. Gas-and-ash plumes rose as high as 2 km above the summit and drifted SW, S, and NE. Two thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.

Source: Instituto Geofísico del Perú (IGP)

San Miguel | 7 December-13 December 2022 | Continuing ActivityCite this Report

San Miguel
Eastern El Salvador

On 7 December MARN reported that activity at San Miguel had decreased. No explosions had been recorded since 29 November and seismicity had decreased. Sulfur dioxide emissions were below the baseline of 300 tons per day.

Source: Ministerio de Medio Ambiente y Recursos Naturales (MARN)

Sheveluch | 7 December-13 December 2022 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that the ongoing eruption at Sheveluch during 2-8 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 60 km NE and E during the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Stromboli | 7 December-13 December 2022 | Continuing ActivityCite this Report

Stromboli
Aeolian Islands (Italy)

INGV reported that lava continued to flow from the vent that opened on 4 December just downslope of the N2 vent in Stromboli’s Area N. The flow had descended the Sciara del Fuoco and reached the coast by around 1700 on 4 December. By 7 December only the top third of the flow was active while the rest of the flow was cooling. The flow was last confirmed to be active in webcam images on 8 December, but afterwards the webcam stream was interrupted. Explosions at three vents in Area N ejected coarse material (bombs and lapilli) less than 80 m high at a rate of 1-7 explosions per hour during 5-11 December.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Suwanosejima | 7 December-13 December 2022 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Islands (Japan)

JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 5-12 December and crater incandescence was visible nightly. No explosions were recorded. Eruption plumes rose as high as 1.7 km above the crater rim and blocks were ejected as far as 200 m from the vent. Ashfall was occasionally reported in Toshima village (3.5 km SSW). The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Villarrica | 7 December-13 December 2022 | Continuing ActivityCite this Report

Villarrica
Central Chile

SERNAGEOMIN reported that during an overflight of Villarrica on 6 December scientists observed intense gas emissions from the lava lake and tephra deposits on the S and SE flanks, as far as 500 m from the crater. During 7-12 December seismicity slightly increased, whitish, low-altitude gas plumes were emitted, and incandescence from the crater was sometimes visible. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and the public was warned that material could be ejected within 500 m of the crater. ONEMI remained the Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)

Whakaari/White Island | 7 December-13 December 2022 | Continuing ActivityCite this Report

Whakaari/White Island
North Island (New Zealand)

On 12 December GeoNet reported continuing unrest at Whakaari/White Island characterized by minor-to-moderate gas-and-steam emissions and low levels of gas. During an overflight on 6 December sulfur dioxide gas emissions averaged around 273 tonnes per day and carbon dioxide emissions averaged around 787 tonnes per day, levels similar to those last measured on 14 October. The lake level had decreased. No signs of ash emissions or other eruptive activity were recorded. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcanic Alert Level remained at 2 (on a scale of 0-5).

Source: GeoNet

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Criteria & Disclaimers

Criteria

The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:

- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.

Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.

It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.

Disclaimers

1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are cover longer time periods and are more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.

3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.

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Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

CVGHM (formerly VSI) - Center of Volcanology and Geological Hazard Mitigation

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

IGNS - Institute of Geological and Nuclear Sciences (New Zealand) - now GNS Science

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

INGV-CT - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (Italy)

INSIVUMEH - Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (Guatemala)

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

NIED - National Research Institute for Earth Science and Disaster Prevention (Japan)

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

OVDAS - Observatorio Volcanologico de los Andes del Sur (Chile)

OFDA - Office of US Foreign Disaster Assistance

ONEMI - Oficina Nacional de Emergencia - Ministerio del Interior (Chile)

OVPDLF - Observatoire Volcanologique du Piton de la Fournaise (France)

OVSICORI-UNA - Observatorio Vulcanologico y Sismologico de Costa Rica, Universidad Nacional (Costa Rica)

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)

Report for Ahyi
Unrest continued to be detected at Ahyi Seamount during 7-13 December. Wake Island hydrophone sensors detected daily signals consistent with explosions during 10-12 December. No signs of underwater plumes were visible in satellite images during 10-11 December; weather clouds obscured the area on 12 December. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).
Source: US Geological Survey

Report for Fuego
INSIVUMEH reported that the eruption at Fuego was ongoing during 7-13 December, though activity had notably intensified during 10-11 December. The seismic network recorded 4-10 explosions per hour during the week, with ash plumes rising as high as 1.2 km above the crater rim. The ash plumes generally drifted 10-20 km NW, W, 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), Finca Palo Verde, Sangre de Cristo (8 km WSW), San Pedro Yepocapa (8 km NW). 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), and El Jute (ESE) drainages, often reaching vegetated areas. Strombolian explosions ejected incandescent material as high as 200 m above the summit on a few of the days.

Activity increased on 10 December. In a special report posted at 2241, INSIVUMEH noted that in the previous minutes multiple explosions of variable intensities produced ash plume that rose 1.2 km above the summit and drifted 30 km W and NW. Pulsating lava fountains rose as high as 500 m above the summit. A lava flow had traveled 800 m down the Ceniza drainage by the time the report was issued, and avalanches of material spalled from its front reached vegetated areas. At 2300 pyroclastic flows descended the Las Lajas drainage several kilometers. Dense ash plumes and pyroclastic flows down the Las Lajas drainage continued for at least an hour. Just before 0030 on 11 December pyroclastic flows traveled several kilometers down the Ceniza drainage on the SW flank. Lava fountains rose as high as 300 m. By 0640 dense ash plumes were rising over 1.2 km above the summit and the lava flow remained active. Avalanches of material from the advancing lava front descended to vegetated areas. Satellite images showed that ash clouds had spread NE, E, and SE, covering a wide area in the department of Sacatepéquez and the central and southern parts of the department of Guatemala. Activity decreased by the early afternoon; lava fountaining, dense ash emissions, and pyroclastic flows had all ceased before 1410.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Report for Lascar
SERNAGEOMIN reported that an eruption at Láscar began at 1236 on 10 December with an explosive event that produced a dense ash plume and pyroclastic flows proximal to the crater. Hikers were near the crater and took video of the eruption. According to SEGEMAR the pyroclastic flows traveled short distances to the N and SE. The ash plume rose about 6 km above the crater rim and drifted SW. The event was coincident with a long-period earthquake detected by the seismic network. Later that day the Alert Level was raised to Yellow (the second lowest level on a four-color scale) and the public were warned to stay at least 5 km away from the crater. ONEMI declared an Alert Level Yellow (the middle level on a three-color scale) for San Pedro de Atacama (70 km NW). CKELAR noted that the thermal anomaly had intensified during the five days prior to the eruption along with increased sulfur dioxide gas emissions.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Servicio Geológico Minero Argentino (SEGEMAR), Instituto Milenio de Investigación en Riesgo Volcánico (CKELAR), Red Geocientífica de Chile

Report for Mauna Loa
HVO reported that activity at Mauna Loa’s Fissure 3 declined during 7-9 December and then ceased on 10 December. The main lava flow had only advanced a small distance during 6-7 December, at a rate of about 6 m per hour, possibly due to a significant breakout that had occurred about 4.5 km upslope of the flow front. Lava erupting from Fissure 3 was greatly reduced by the morning of 8 December. Lava overtopped channels near the vent but had not advanced farther than 4.4 km from the vent by 0930. The channel at lower elevations appeared to be drained and was likely no longer feeding the main flow which had stalled about 2.8 km from the Daniel K. Inouye Highway (Saddle Road). The sulfur dioxide emission rate had declined to 30,000 tonnes per day. By 1130 on 9 December low lava fountains at Fissure 3 fed flows that traveled as far as 2.65 km NE. By 0700 on 10 December a lava pond in the Fissure 3 vent was visible and fed short lava flows that stagnated at 2.6 km. Tremor levels were slowly declining and the sulfur dioxide emission rate was about 2,000 tonnnes per day. Lava was confined to the small pond by 1435 and gas emissions had significantly declined. HVO lowered the Volcano Alert Level to Watch (the second highest level on a four-level scale); the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

No activity was visible on the flow field overnight during 10-11 December, and by 0700 on 11 December the Fissure 3 vent was barely incandescent. Scientists observed no lava movement and only minor incandescence at the vent during an overflight in the early morning of 12 December. They heard a small explosion that accompanied a spray of spatter from the W end of the fissure. On 13 December HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Yellow and noted that lava effusion at Fissure 3 had ceased on 10 December, sulfur dioxide emissions had decreased to near pre-eruption background levels, and volcanic tremor and earthquakes associated with the eruption were greatly diminished.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Semeru
BNPB reported that residents continued to be impacted by the collapses and large pyroclastic flows on Semeru’s SE flank on 4 December. As of 6 December, there were 781 people spread across 21 evacuation shelters and heavy ashfall prevented aid from easily reaching Pronojiwo Village, according to BNPB. Kajar Kuning was the worst affected village.

PVMBG reported that lava continued to erupt from the summit vent during 4-9 December, though activity generally declined. Ongoing thermal anomalies were identified in satellite images, though the intensity had decreased. The rate of deformation had declined based on tiltmeter data. Four pyroclastic flows moved as far as 6 km down the SE flanks, and avalanches of material traveled 300-500 m SE. At 0521 on 8 December a gray-to-white ash plume rose around 300 m above the summit and drifted N. At 0536 a gray ash plume rose 400 m and drifted N, as reported by a ground-based observer. A dense gray ash plume rose 500 m and drifted N at 0521 on 9 December. Later that day, at 1200, the Alert Level was lowered to 3 (the second highest level on a scale of 1-4) and the public was warned to stay at least 5 km away from the summit, as far as 13 km from the summer on the SE flanks, and 500 m from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Eruptive activity continued during 10-13 December. At 0653 on 10 December a dense white-to-gray ash plume rose about 700 m above the summit and drifted N. White-and-gray ash plume were visible at 0652 on 11 December and 0727 on 12 December rising at least 500 m and drifting S and SW, respectively.
Sources: Badan Nacional Penanggulangan Bencana (BNPB), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Aira
JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 5-12 December consisting of a few eruptive events and three explosions. Crater incandescence was visible nightly. Explosions produced ash plumes that rose as high as 2.7 km above the crater rim and ejected large blocks as far as 1.1 km away. Sulfur dioxide emissions were high at 2,800 tons per day on 6 December. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)

Report for Alaid
KVERT reported that the eruption at Alaid was ongoing during 1-8 December. A thermal anomaly was identified in satellite images on 2 and 8 December; weather clouds obscured observations on the other days. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Cotopaxi
IG reported that the low-level eruption at Cotopaxi continued during 7-13 December characterized by steam-and-gas emissions and occasional ash emissions. Sulfur dioxide emissions measured by satellite almost daily averaged 665-2,745 tons per day. Steam-and-gas emissions observed during 7-10 December rose as high as 2 km above the crater rim and drifted SW, W, and NW. Ash emissions during 0758-0816 on 8 December rose 1 km and drifted WNW. The Washington VAAC issued three advisories noting that ash rose 800-1,100 m and drifted W. A tremor signal that started at 0832 on 9 December was probably related to gas-and-ash emissions, though cloudy weather conditions prevented visual confirmation. During the night of 9-10 December several steam-and-ash emissions were identified in satellite images rising as high as 1.1 km and drifting NW. Minor ashfall was reported in Conocoto-Pichincha in the morning of 10 December. At 0930 on 11 December the seismic stations recorded a signal related to gas-and-ash emissions that rose 2 km and drifted W. Ash fell in Control Caspi, located at the S entrance to Parque Nacional Cotopaxi. Several gas-and-steam emissions with low ash content were visible that afternoon and during the morning of 12 December rising as high as 500 m and drifting W. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)

Report for Ebeko
KVERT reported that moderate activity at Ebeko was ongoing during 1-8 December. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 1-2 and 7 December generated ash plumes that rose to 2.5 km (8,200 ft) a.s.l. and drifted NE. The volcano was quiet or obscured by weather clouds on the other days of the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Great Sitkin
AVO reported that slow lava effusion continued at Great Sitkin during 27 November-11 December based on satellite images. Cloud cover mostly prevented satellite and webcam observations during 7-12 December. Seismicity remained at low levels. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Kilauea
HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-8 December and entered the lava lake, though the eruption rate had diminished, and the floor of the crater had deflated. The eruption ceased on 9 December. During 10-12 December the lake crusted over, no incandescence was visible, and sulfur dioxide emissions had decreased to near pre-eruption background levels. On 13 December HVO lowered the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code to Yellow (the second lowest level on a four-color scale).
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Merapi
BPPTKG reported that the eruption at Merapi continued during 2-8 December and seismicity remained at high levels. The SW lava dome produced two lava avalanches that traveled as far as 1.6 km down the SW flank (upstream in the Kali Bebeng drainage). No significant morphological changes to the central and SW lava domes were evident. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location.
Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)

Report for Pavlof
AVO reported that seismic tremor and a few low-frequency earthquakes at Pavlof indicated continuing unrest during 7-13 December; one explosion was recorded on 7 December. No explosions or lava flow activity was detected in seismic, infrasound, satellite, or webcam data during the rest of the week. The report noted that events on 3 December resulted in the erosion of a narrow, 2-km-long gully beneath the ice below the vent. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Sabancaya
Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 December with a daily average of 40 explosions. Gas-and-ash plumes rose as high as 2 km above the summit and drifted SW, S, and NE. Two thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.
Source: Instituto Geofísico del Perú (IGP)

Report for San Miguel
On 7 December MARN reported that activity at San Miguel had decreased. No explosions had been recorded since 29 November and seismicity had decreased. Sulfur dioxide emissions were below the baseline of 300 tons per day.
Source: Ministerio de Medio Ambiente y Recursos Naturales (MARN)

Report for Sheveluch
KVERT reported that the ongoing eruption at Sheveluch during 2-8 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 60 km NE and E during the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Stromboli
INGV reported that lava continued to flow from the vent that opened on 4 December just downslope of the N2 vent in Stromboli’s Area N. The flow had descended the Sciara del Fuoco and reached the coast by around 1700 on 4 December. By 7 December only the top third of the flow was active while the rest of the flow was cooling. The flow was last confirmed to be active in webcam images on 8 December, but afterwards the webcam stream was interrupted. Explosions at three vents in Area N ejected coarse material (bombs and lapilli) less than 80 m high at a rate of 1-7 explosions per hour during 5-11 December.
Source: Sezione di Catania - Osservatorio Etneo (INGV)

Report for Suwanosejima
JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 5-12 December and crater incandescence was visible nightly. No explosions were recorded. Eruption plumes rose as high as 1.7 km above the crater rim and blocks were ejected as far as 200 m from the vent. Ashfall was occasionally reported in Toshima village (3.5 km SSW). The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)

Report for Villarrica
SERNAGEOMIN reported that during an overflight of Villarrica on 6 December scientists observed intense gas emissions from the lava lake and tephra deposits on the S and SE flanks, as far as 500 m from the crater. During 7-12 December seismicity slightly increased, whitish, low-altitude gas plumes were emitted, and incandescence from the crater was sometimes visible. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and the public was warned that material could be ejected within 500 m of the crater. ONEMI remained the Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)

Report for Whakaari/White Island
On 12 December GeoNet reported continuing unrest at Whakaari/White Island characterized by minor-to-moderate gas-and-steam emissions and low levels of gas. During an overflight on 6 December sulfur dioxide gas emissions averaged around 273 tonnes per day and carbon dioxide emissions averaged around 787 tonnes per day, levels similar to those last measured on 14 October. The lake level had decreased. No signs of ash emissions or other eruptive activity were recorded. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcanic Alert Level remained at 2 (on a scale of 0-5).
Source: GeoNet