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Smithsonian / USGS Weekly Volcanic Activity Report

Weekly Volcanic Activity Map

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 6 December-12 December 2023
Name Country Volcanic Province Eruption Start Date Report Status
Ambae Vanuatu Vanuatu Volcanic Arc New
Ioto Japan Ogasawara Volcanic Arc New
Marapi Indonesia Sunda Volcanic Arc 2023 Dec 3 New
Ulawun Papua New Guinea Bismarck Volcanic Arc New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
East Epi Vanuatu Vanuatu Volcanic Arc Continuing
Ebeko Russia Kuril Volcanic Arc 2022 Jun 11 Continuing
Great Sitkin United States Aleutian Ridge Volcanic Arc 2021 May 25 Continuing
Karangetang Indonesia Sangihe Volcanic Arc Continuing
Kirishimayama Japan Ryukyu Volcanic Arc Continuing
Krakatau Indonesia Sunda Volcanic Arc Continuing
Lewotolok Indonesia Sunda Volcanic Arc 2020 Nov 27 Continuing
Mayon Philippines Eastern Philippine Volcanic Arc 2023 Apr 27 ± 2 days Continuing
Merapi Indonesia Sunda Volcanic Arc 2020 Dec 31 Continuing
Semeru Indonesia Sunda Volcanic Arc 2017 Jun 6 Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
Shishaldin United States Aleutian Ridge Volcanic Arc Continuing
Stromboli Italy Aeolian Volcanic Arc 1934 Feb 2 Continuing
Suwanosejima Japan Ryukyu Volcanic Arc 2004 Oct 23 Continuing
Ubinas Peru Central Andean Volcanic Arc 2024 May 6 Continuing
Villarrica Chile Southern Andean Volcanic Arc 2014 Dec 2 ± 7 days Continuing
Yasur Vanuatu Vanuatu Volcanic Arc 1270 ± 110 years Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,553 individual reports over 1,240 weeks (average of 17 per week) on 338 different volcanoes.

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Adams Cotopaxi Iliwerung Llaima Popocatepetl Sumisujima
Agung Cuicocha Inielika Lokon-Empung Purace Sundoro
Ahyi Cumbal Ioto Lonquimay Puyehue-Cordon Caulle Suoh
Aira Dabbahu Irazu Lopevi Rabaul Suretamatai
Akan Davidof Iwatesan Machin Raikoke Suwanosejima
Alaid Dempo Iya Makushin Ranakah Taal
Alu-Dalafilla Descabezado Grande Izu-Torishima Maly Semyachik Raoul Island Tair, Jebel at
Ambae Dieng Volcanic Complex Jackson Segment Manam Rasshua Takawangha
Ambang Dukono Kaba Manda Hararo Raung Talang
Ambrym East Epi Kadovar Marapi Redoubt Tambora
Anatahan Ebeko Kaitoku Seamount Maroa Reventador Tanaga
Aniakchak Ebulobo Kama'ehuakanaloa Martin Reykjanes Tandikat-Singgalang
Antillanca Volcanic Complex Edgecumbe Kambalny Masaya Rincon de la Vieja Tangkoko-Duasudara
Antuco Egon Kanaga Matthew Island Rinjani Tangkuban Parahu
Apoyeque Ekarma Kanlaon Maule, Laguna del Ritter Island Tara, Batu
Arenal Eldey Karangetang Mauna Loa Rotorua Ta'u
Asamayama Erebus Karkar Mayon Ruang Taupo
Askja Erta Ale Karthala McDonald Islands Ruapehu Telica
Asosan Etna Karymsky Melebingoy Ruby Tenerife
Atka Volcanic Complex Etorofu-Yakeyama [Grozny Group] Kasatochi Melimoyu Ruiz, Nevado del Tengger Caldera
Augustine Eyjafjallajokull Katla Merapi Sabancaya Three Sisters
Avachinsky Fagradalsfjall Katmai Midagahara Sakar Tinakula
Awu Fernandina Kavachi Misti, El Salak Tofua
Axial Seamount Fogo Kelimutu Miyakejima San Cristobal Tokachidake
Azul, Cerro Fonualei Kelud Momotombo San Miguel Tolbachik
Azumayama Fournaise, Piton de la Kerinci Monowai San Vicente Toliman
Bagana Fourpeaked Ketoi Montagu Island Sangay Tongariro
Balbi Fuego Kharimkotan Moyorodake [Medvezhia] Sangeang Api Trident
Bamus Fujisan Kick 'em Jenny Mutnovsky Santa Ana Tungurahua
Banda Api Fukutoku-Oka-no-Ba Kie Besi Myojinsho Santa Maria Turrialba
Bardarbunga Galeras Kikai Nabro Sao Jorge Ubinas
Barren Island Galunggung Kilauea Negra, Sierra Sarigan Ugashik-Peulik
Batur Gamalama Kirishimayama Negro, Cerro Sarychev Peak Ukinrek Maars
Bezymianny Gamkonora Kita-Ioto Nightingale Island Saunders Ulawun
Bogoslof Gareloi Kizimen Nishinoshima Savo Unnamed
Brava Gaua Klyuchevskoy Nisyros Semeru Unnamed
Bristol Island Gorely Kolokol Group Novarupta Semisopochnoi Veniaminof
Bulusan Great Sitkin Koryaksky NW Rota-1 Seulawah Agam Villarrica
Calbuco Grimsvotn Krakatau Nyamulagira Sheveluch Vulcano
Callaqui Guagua Pichincha Krummel-Garbuna-Welcker Nyiragongo Shishaldin West Mata
Cameroon Guallatiri Krysuvik-Trolladyngja Ofu-Olosega Simbo Westdahl
Campi Flegrei Guntur Kuchinoerabujima Okataina Sinabung Whakaari/White Island
Campi Flegrei del Mar di Sicilia Hachijojima Kurikomayama Okmok Sinarka Witori
Cayambe Hakoneyama Kusatsu-Shiranesan Ontakesan Siple Wolf
Chachadake [Tiatia] Heard Kverkfjoll Oraefajokull Sirung Wrangell
Chaiten Hekla La Palma Osorno Slamet Yakedake
Chiginagak Helgrindur Lamington Pacaya Snaefellsjokull Yasur
Chikurachki Hierro Lamongan Pagan Soputan Yellowstone
Chiles-Cerro Negro Hokkaido-Komagatake Langila Palena Volcanic Group Sorikmarapi Yufu-Tsurumi
Chillan, Nevados de Home Reef Lanin Paluweh Sotara Zaozan [Zaosan]
Chirinkotan Hood Lascar Panarea Soufriere Hills Zavodovski
Chirpoi Huaynaputina Late Papandayan Soufriere St. Vincent Zhupanovsky
Ciremai Hudson, Cerro Lateiki Pavlof South Sarigan Seamount Zubair Group
Cleveland Huila, Nevado del Lengai, Ol Doinyo Pelee Spurr
Colima Hunga Tonga-Hunga Ha'apai Leroboleng Peuet Sague St. Helens
Colo Ibu Lewotobi Pinatubo Stromboli
Concepcion Ijen Lewotolok Planchon-Peteroa Sulu Range
Copahue Iliamna Little Sitkin Poas Sumbing
 News Feeds and Google Placemarks


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The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. At the end of each report is a list of the sources used. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. This feature was first made available on 5 March 2008.



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A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

 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.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

5. USGS Disclaimer Statement for this Website:

Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL: https://volcano.si.edu/reports_weekly.cfm

 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 Ambae
On 4 December the Vanuatu Meteorology and Geohazards Department (VMGD) reported that steam-and-gas emissions at Ambae were ongoing based on satellite images. According to the Wellington VAAC an eruption produced an ash plume visible in satellite images at 1240 on 11 December that rose to 4.3 km (14,000 ft) a.s.l. and drifted NE. The Alert Level remained at 2 (on a scale of 0-5) and the public was warned to stay outside of the Danger Zone, defined as a 2-km radius around the active vents in Lake Voui, and away from drainages during heavy rains.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)
Report for Ioto
According to a news article the eruption at Ioto (Iwo-jima), from a submarine vent about 1 km off the SE coast at Okinahama, continued on 4 December. During an overflight of the volcano passengers observed explosions that produced 100-m-high black plumes every few minutes. Ejected material combined with wave erosion transformed the shape of the island into a “J” shape, 500 m long and with the curved part about 200 m offshore of the main island. The island was covered with brown ash and blocks, and the surrounding water was green to brown in color and there were areas of floating pumice.
Source: NHK (Japan Broadcasting Corporation)
Report for Marapi
PVMBG reported that eruptive activity at Marapi was ongoing during 6-12 December, though foggy and raining weather conditions often prevented visual observations of the summit. White-and-gray ash plumes rose 400-500 m and drifted NE, E, and W on 6 December. Eruptive events were recorded by the seismic network at 1009 on 6 December and at 0141 on 7 December though no ash emissions were observed. On 11 December white-and-gray ash plumes rose 200-400 m above the summit and drifted E and S. At 0805 that same day a dense gray ash plume rose 400 m above the summit and drifted N. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 3 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ulawun
According to ReliefWeb, the U.S. Agency for International Development (USAID) reported that the 20 November eruption at Ulawun resulted in five deaths and the evacuation of more than 16,000 people, with many more affected, as of 9 December. Ashfall from the eruption impacted oil palm trees, water sources, household gardens, and nearby properties.
Source: ReliefWeb
Report for Aira
JMA reported ongoing activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano) during 4-11 December, with incandescence at the crater observed nightly. Small eruptive events were recorded during 4-8 December. Sulfur dioxide emissions were high, averaging 2,900 tons per day on 8 December. Explosions at 1028 and 1533 on 10 December produced ash plumes that rose 1.5-1.8 km above the crater rim and drifted N. An eruptive event at 1748 on that same day produced an ash plume that rose 1.2 km and drifted N. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.
Source: Japan Meteorological Agency (JMA)
Report for East Epi
On 4 December the Vanuatu Meteorology and Geohazards Department (VMGD) reported that minor unrest continued at East Epi during November. Volcanic seismicity was sustained, though no activity was observed above the ocean surface. The Alert Level remained at 1 (on a scale of 0-5) and the public was warned to stay outside of the Danger Zone, defined as a 2-km radius around the active submarine vent.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)
Report for Ebeko
KVERT reported that moderate explosive activity at Ebeko was ongoing during 1-7 December. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during the week generated ash plumes that rose as high as 3 km (10,000 ft) a.s.l and drifted E, NE, and N. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; 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 6-12 December with a thick flow in the summit crater mainly expanding E. Seismicity was low. Weather clouds obscured views during most of the week. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Karangetang
PVMBG lowered the Alert Level for Karangetang to 2 (on a scale of 1-4) on 29 November due to declining activity. According to a news article seismic data and visual observations indicated that effusion had decreased or ceased and that lava avalanches were no longer observed. Seismicity decreased and deformation data indicated deflation. The public was warned to stay 1.5 km away from both Main Crater and North Crater with an extension to 2.5 km on the S and SE flanks.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Antara News
Report for Kirishimayama
JMA lowered the Alert Level for Kirishimayama to 1 (on a 5-level scale) on 6 December. The number of volcanic earthquakes had increased during July-August in an area around the NE side of Karakunidake and on 15 September and had remained low since then. Minor inflation detected in May slowed in October and was no longer detected in November. Fumarolic areas remained at normal levels.
Source: Japan Meteorological Agency (JMA)
Report for Krakatau
PVMBG reported that the eruption at Krakatau continued during 6-12 December. White-and-gray ash plumes that were sometimes dense and dark rose as high as 1.2 km above the summit and drifted NE, N, and NW during 6-8 and 10 December. White plumes that rose as high as 150 m and drifted N and NE were visible on the other days. Webcam images posted with the daily reports showed incandescence at the vent. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay at least 5 km away from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 6-12 December. White steam-and-gas plumes rose 300-500 m above the summit and drifted in multiple directions on 6, 9, and 12 December. White-and-gray ash plumes rose 300-400 m during 7-8 and 10-11 December and drifted E, N, and W. Ejections of incandescence lava at the summit were visible on 6 and 12 December. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay at least 2 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Mayon
PHIVOLCS lowered the Alert Level for Mayon to 2 (on a 0-5 scale) at 0800 on 8 December due to a continuing decline in activity during the previous several weeks. Volcanic earthquakes indicating lava extrusion, degassing, and occasional fracturing beneath the edifice decreased from an average of 11 events per day in November to almost zero events per day in the first week of December. Similarly, the average number of daily rockfalls and pyroclastic density currents (PDCs, or pyroclastic flows) decreased from monthly averages of 122 to 87 and 5 to 2 events per day, respectively, from October to November; there were almost zero events per day in the first week of December. Incandescence at the summit crater and from lava flows had declined starting in the last week of November. The length of the lava flows in the Mi-Isi (S), Bonga (SE), and Basud (E) drainages had remained at 2.8 km, 3.4 km, and 1.1 km, respectively, since July and August; the newest lava deposits observed since 23 November were in the Bonga within 400 m of the summit. Sulfur dioxide gas emissions peaked at 4,756 tonnes per day (t/d) on 16 August and had been variable but declining overall since; a monthly average of 1,417 t/d in November decreased to an average of 1,095 t/d in December. Electronic Distance Measuring (EDM), continuous GPS, and electronic tilt monitoring data showed continuing deformation. Deflation was detected in GPS data beginning around August-September and in tilt data starting in November. Net inflation in the longer-term was indicated in electronic tilt data as far back as June and in EDM data starting in February. Residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Merapi
BPPTKG reported that the eruption at Merapi (on Java) continued during 1-8 December. Two pyroclastic flows traveled S as far as 1.3 km down the upper part of the Boyong drainage and four pyroclastic flows traveled SW as far as 3 km down the upper parts of the Bebeng and Krasak drainages during 1-7 December. Minor ashfall occurred in the Sawangan District (15 km W), Magelang, and the Selo District (5 km NNE), Boyolali. The SW lava dome produced a total of 192 lava avalanches; 23 traveled as far as 1.5 km down the Boyong drainage and 169 traveled as far as 1.7 km down the Bebeng drainage. According to BNPB several dark gray pyroclastic flows were detected by the seismic network starting at 1449 on 8 December and traveled as far as 3.5 km down the Krasak drainage on the SW flank. Ash mixed with rain fell in Krinjing (5 km WNW) and Paten (9 km WNW) villages, Dukun District in the Magelang Regency, as well as in the Stabelan (4 km NW), Klakah (4 km NW), and Tlogolele (5 km NW) villages in the Selo District, Boyolali Regency. BPPTKG noted that minor morphological changes to the SW lava dome were identified in webcam images due to continuing lava effusion and collapses of material. Seismicity remained at high levels during the week. 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.
Sources: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG), Badan Nacional Penanggulangan Bencana (BNPB)
Report for Semeru
PVMBG reported that eruptive activity continued at Semeru during 6-12 December. Daily white-and-gray ash plumes that were often dense rose as high as 1 km above the summit and drifted in multiple directions during 8-12 December. The Alert Level remained at 3 (third highest on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Sheveluch
KVERT reported that the eruption at Sheveluch continued during 1-7 December. A daily thermal anomaly was identified in satellite images. During 3-6 December plumes of resuspended ash drifted about 230 km E and SE. The Aviation Color Code remained at Orange (the third 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 Shishaldin
AVO reported that unrest continued at Shishaldin during 6-12 December. Seismicity remained low with small, frequent, low-frequency earthquakes recorded daily. Weak explosions were detected in infrasound data during 6 and 8-9 December, though none produced ash. Elevated surface temperatures were identified in a clear satellite image during 8-9 December, and minor steaming at the summit was observed in webcam images during 8-10 December. Cloudy weather sometimes prevented views of the summit. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Stromboli
INGV reported that eruptive activity continued at Stromboli during 4-10 December. Webcam images showed Strombolian activity at three vents in Area N (two at N1 and one at N2), within the upper part of the Sciara del Fuoco, and from two vents in Area C-S (South-Central Crater) in the crater terrace. Explosions of low-to-medium intensities occurred at a rate of 5-6 per hour at Area N2 and ejected mainly coarse material (bombs and lapilli), sometimes mixed with ash, lower than 150 m above the vents. Variable-intensity explosions in sector S2 (Area C-S) averaged 5-9 per hour from the vents, ejecting a mix of coarse material higher than 150 m. The Dipartimento della Protezione Civile maintained the Alert Level at Yellow (the second lowest level on a four-level scale).
Sources: Dipartimento della Protezione Civile, Sezione di Catania - Osservatorio Etneo (INGV)
Report for Suwanosejima
JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 4-11 December and crater incandescence was visible nightly. No explosions were detected, though ash plumes rose as high as 900 m above the crater rim. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Ubinas
According to the Washington VAAC an ash puff from Ubinas was identified in a satellite image at 0040 on 11 December rising 5.5 km (18,000 ft) a.s.l. and drifting NW. Webcam images at 0620 and 1220 showed continuous steam emissions possibly containing diffuse ash rising as high as 7 km (23,000 ft) a.s.l. Steam emissions containing small amounts of ash were visible at 1810. Emissions were no longer visible in satellite and webcam images at 0010 on 12 December.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Villarrica
POVI reported that vigorous Strombolian activity at Villarrica was visible overnight during 2-3 December. Incandescent material was ejected as high as 85 m above the crater rim. SERNAGEOMIN reported that at 2030 on 9 December a long-period (LP) earthquake associated with fluid movement was accompanied by an emission that rose 120 m above the vent and drifted ENE. The Volcanic Alert level remained at Yellow (the third level on a four-level scale) according to SERNAGEOMIN.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Proyecto Observación Villarrica Internet (POVI)
Report for Yasur
On 4 December the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a level of “major unrest,” as defined by the Alert Level 2 status (the middle level on a scale of 0-4) during November. Recent satellite observations indicated an increase in steam, gas, and ash emissions from the summit crater. Explosions continued, with some ejecting bombs that landed back in and around the crater. The public was reminded to not enter the restricted area within 600 m around the boundaries of the Permanent Exclusion Zone, defined by Danger Zone A on the hazard map.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)