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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 15 December-21 December 2021
Name Country Volcanic Province Eruption Start Date Report Status
Davidof United States Aleutian Ridge Volcanic Arc — New
Fagradalsfjall Iceland Iceland Neovolcanic Rift Volcanic Province — New
Hunga Tonga-Hunga Ha'apai Tonga Tofua Volcanic Arc — New
Piton de la Fournaise France Reunion Hotspot Volcano Group — New
San Cristobal Nicaragua Central America Volcanic Arc — New
Semeru Indonesia Sunda Volcanic Arc 2017 Jun 6 New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Fuego Guatemala Central America Volcanic Arc 2002 Jan 4 Continuing
Great Sitkin United States Aleutian Ridge Volcanic Arc 2021 May 25 Continuing
Karymsky Russia Eastern Kamchatka Volcanic Arc 2024 Jun 20 Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group 2024 Sep 15 Continuing
La Palma Spain Canary Volcanic Province — Continuing
Lewotolok Indonesia Sunda Volcanic Arc — Continuing
Manam Papua New Guinea Bismarck Volcanic Arc 2018 May 10 ± 10 days Continuing
Merapi Indonesia Sunda Volcanic Arc 2020 Dec 31 Continuing
Pavlof United States Aleutian Ridge Volcanic Arc — Continuing
Popocatepetl Mexico Trans-Mexican Volcanic Belt 2005 Jan 9 Continuing
Santa Maria Guatemala Central America Volcanic Arc 1922 Jun 22 Continuing
Semisopochnoi United States Aleutian Ridge Volcanic Arc — Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
Suwanosejima Japan Ryukyu Volcanic Arc 2004 Oct 23 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 20,652 individual reports over 1,244 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
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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)

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Report for Davidof
AVO reported that the earthquake swarm at Davidof declined during 14-21 December with up to two shallow earthquakes recorded per day. A shallow earthquake recorded on 17 December was a M 3.9. The closest seismometers are approximately 15 km E, on Little Sitkin Island. Davidof is also monitored by satellite data and remote infrasound and lightning networks. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Fagradalsfjall
Icelandic Meteorological Office (IMO) reported that as of 18 December no eruptive activity at the Krýsuvík-Trölladyngja volcanic system had been observed for the previous three months, so the eruption was officially declared to have ended on 18 September. IMO noted that deformation data showed continuing magma accumulation beneath Geldingadalir.

Seismicity increased at 1800 on 21 December in an area 2-4 km NE of Geldingadalir. The seismicity notably intensified at 0030 on 22 December with 1-10 earthquakes recorded per minute, bringing the total number of events to about 900 by 0222. The largest event was a M 3.3. The Aviation Color Code was raised to Orange.
Source: Icelandic Meteorological Office (IMO)
Report for Hunga Tonga-Hunga Ha'apai
According to a news article, Tonga’s head geologist reported that an eruption at Hunga Tonga-Hunga Ha'apai began at 0935 on 20 December. The eruption produced a steam-rich gas-and-ash plume that initially rose to 6 km (19,700 ft) a.s.l. by 0940, and then continued to ascend to 16 km (52,500 ft) a.s.l. and drift N. Lightning was present in the plume and about 9 kilotons of sulfur dioxide was detected in satellite data. Residents of Vava'u, 270 km NE, heard a series of explosions at a rate of several times per minute for the first 1-2 hours, after which they became sporadic. Explosions were heard through the night within the first 12 hours of the eruption. Ash emissions ceased at around 0200 on 21 December, though intermittent gas plumes with lightning continued at least through that day. Based on pilot observations, the Wellington VAAC noted that plumes rose 6.1-12.2 km (20,000-40,000 ft) a.s.l. and drifted N and NE on 21 December.
Sources: Matangi Tonga Online, Simon Carn, TROPOMI SO2, National Environmental Satellite, Data, and Information Service (NESDIS), Tonga Meteorological Services, Government of Tonga, Scott Bryan, Queensland University of Technology, personal comm, Wellington Volcanic Ash Advisory Center (VAAC)
Report for Piton de la Fournaise
OVPF reported that a seismic crisis at Piton de la Fournaise began at 0105 on 22 December and was accompanied by rapid deformation beneath the S flank. Volcanic tremor located beneath the S part of the caldera began at 0330, signifying the arrival of magma at the surface. Webcam images showed that at least three fissures opened on the S flank, producing lava fountains and descending flows.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Report for San Cristobal
INETER reported that a series of five low- to medium-intensity explosions were recorded at San Cristóbal between 0522-0526 on 15 December. Ash plumes rose 2.5 km above the crater rim and drifted W, causing ashfall in La Grecia, Rancherías (8 km NW), and El Viejo (18 km SW). Rocks were ejected 500 m from the vent onto the flanks.
Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Report for Semeru
PVMBG reported that the eruption at Semeru continued during 14-21 December. Incandescent lava avalanches from the end of a 1.8-km-long lava flow in the Kobokan drainage on the SE flank descended 200-800 m during 14-15 December. Crater incandescence was visible overnight during 15-16 December and two incandescent avalanches traveled 500 m from the crater. On 16 December three pyroclastic flows, recorded at 0901, 0930, and 1542, traveled a maximum of 4.5 km down the SE flank. At 2300 PVMBG raised the Alert Level to 3 (on a scale of 1-4), noting increasing distances of pyroclastic flows and expanded the exclusion zone to a 5 km radius around the crater and 13 km in the SSE sector. The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, and other drainages originating on Semeru including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Two pyroclastic flows descended 500 m during 17-18 December and ash plumes rose 200 m and drifted SW. At 0556 on 20 December an eruptive event produced an ash plume that rose 1.5 km above the crater rim. One pyroclastic flow traveled 3 km SE that day and another one the next day. The crater was incandescent overnight during 20-21 December when weather permitted visual observations. According to BNPB, 11,658 people were in 52 evacuation centers by 14 December.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Badan Nacional Penanggulangan Bencana (BNPB)
Report for Aira
JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were detected during 13-20 December. The sulfur dioxide emission rate was slightly high at 1,200 tons per day on 13 December. Crater incandescence was visible at night during 13-17 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 Fuego
INSIVUMEH reported that 3-13 explosions per hour were recorded at Fuego during 14-21 December, generating ash plumes as high as 1.1 km above the crater rim and periodic shock waves that were felt in communities around the volcano. Ash plumes drifted as far as 40 km NW, W, SW, and SE; ashfall was reported 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), San Pedro Yepocapa (8 km NW), Sangre de Cristo (8 km WSW), finca Palo Verde, Santa Sofía (12 km SW), and Yucales (12 km SW) during 16-18 and 20-21 December. Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), and Las Lajas (SE) drainages, often reaching vegetated areas. Explosions ejected incandescent material up to 100-300 m above the summit during 14-15 and 17-19 December. Winds lifted “curtains” of ash around the volcano during 18-19 December, and crater incandescence was visible overnight during 20-21 December.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Great Sitkin
AVO reported that slow lava effusion at Great Sitkin likely continued during 15-19 December and very low seismicity persisted. A radar image acquired during 14-15 December showed a growing flow field with lava lobes advancing down the N, W, and S flanks. Elevated surface temperatures at the summit were detected overnight during 15-16 and 18-19 December. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Karymsky
KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 11, 13, and 15-16 December. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
HVO reported that lava effusion continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 14-20 December. The sulfur dioxide emission rate was about 1,400 tonnes per day on 16 December. By 19 December the lake had risen a total of 69 m since the beginning of the eruption. A series of partial overturns of the lake was visible on 20 December, though by the next morning there was no lava effusion from the vent and the lake had crusted over. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for La Palma
Observations at La Palma on 15 December showed no lava flowing from vents at the W base of the main cone, from tubes, or at the lava delta in the Las Hoyas area. During 15-20 December tremor levels were at background levels and seismicity was very low at all depths. Sporadic gas emissions rose from the vents and from cooling lava flows. Small collapses from the walls of the main and secondary cone craters were visible through the week. Sulfur dioxide levels varied between extremely low and medium values (less than 5 to 999 tons per day) consistent with a cooling and degassing lava flow field. Even though air quality levels had improved overall, a few measurements of diffuse carbon dioxide emissions showed levels around 9 times average background. Authorities warned the public to exercise caution in areas surrounding the flow field due to volcanic gases in the area and noted that lava flows, although cooling, remained at high temperatures.
Sources: Instituto Volcanológico de Canarias (INVOLCAN), Gobierno de Canaries, Instituto Geográfico Nacional (IGN)
Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 14-21 December. White, gray, and black ash plumes that were sometimes dense rose as high as 1 km above the summit. Incandescent material was ejected from the vent up to 300 m often to the E and SE, but sometimes in all directions. Rumbling and booming sounds were often heard. The Alert Level remained at 3 (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 Manam
The Darwin VAAC reported that a thermal anomaly over Manam was identified in satellite images on 15 December, prior to an ash emission that rose to 6.1 km (20,000 ft) a.s.l. and drifted SW. An ash plume rising to the same altitude was visible in satellite images on 16 December but had dissipated by mid-morning. Later that day diffuse ash plumes rising to 2.4 km (8,000 ft) a.s.l. were visible in satellite images and reported by ground observers, according to RVO. An eruptive event was recorded by the seismic network at 0600 on 17 December; ground observations indicated that an ash plume likely rose to 3 km (10,000 ft) a.s.l. and drifted SE. At 0840 ash emissions identified in satellite images and by observers rose to 3 km, drifted SE, and dissipated within about five hours. At 0220 on 18 December an ash plume rose to 3 km, drifted SE, and again dissipated within about five hours; a thermal anomaly over the summit was visible in the satellite data. At 1600 on 21 December an ash plume rose to 1.5 km (5,000 ft) a.s.l., drifted NE, and dissipated within about three hours. The thermal anomaly persisted.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Merapi
BPPTKG reported no significant morphological changes at Merapi’s lava domes, located just below the SW rim and in the summit crater, during 10-16 December. The estimated dome volumes were almost 1.63 million cubic meters for the SW dome and just over 3 million cubic meters for the summit dome. The intensity of the seismic signals remained at high levels. As many as 116 lava avalanches traveled a maximum of 2 km SW down the Bebeng drainage, and three pyroclastic flows traveled a maximum of 2.2 km SW. At 1643 on 18 December a pyroclastic flow advanced 2 km SW and produced an ash plume that rose 400 m. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location.
Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)
Report for Pavlof
AVO reported seismicity at Pavlof was elevated during 14-21 December and was mainly characterized by periods of sustained tremor and discrete low-frequency events. Strongly elevated surface temperatures were visible in satellite images during 14-16 and 18-21 December, consistent with lava effusion. Numerous small explosions were recorded during 19-21 December. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Popocatepetl
CENAPRED reported that each day during 14-21 December there were 11-23 steam-and-gas emissions from Popocatépetl that drifted NW, NE, E, and SE. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale).
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Santa Maria
INSIVUMEH reported that in recent months the dome in Caliente crater, the active part of Santa María’s Santiaguito lava-dome complex, has grown due to a higher rate of extrusion. Blocky lava descending the W flank of the dome produced block avalanches, though avalanches often descended the flanks in multiple directions. A larger number of volcano-tectonic earthquakes began to be recorded on 11 December simultaneously with increased surficial activity. The lava extrusion rate increased on 16 December at the WSW part of the dome, causing intense incandescence at the dome, an increase in block avalanches on the W, S, and E flanks, and higher gas emissions. On 17 December strong explosions produced ash plumes that rose as high has 2 km above the dome and drifted 30 km W. Strong explosions continued to be recorded though 19 December; explosions were weak during 20-21 December. Ash fell in areas downwind including San Marcos Palajunoj (8 km SW) and Loma Linda (6 km WSW) during 16-18 December. Strong incandescence and block avalanches on the W, SW, and S flanks continued through 21 December.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semisopochnoi
AVO reported that low-level eruptive activity and elevated seismicity at Semisopochnoi's North Cerberus crater continued during 15-21 December. Small daily explosions were detected in seismic and infrasound data. Low-level ash-and-steam emissions were observed daily by webcams and were occasionally identified in satellite images when weather conditions permitted. Elevated surface temperatures were also identified in satellite data during 15-17 and 19-20 December. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 10-17 December. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Suwanosejima
JMA reported that crater incandescence at Suwanosejima's Ontake Crater was visible nightly during 13-20 December. The number of explosions increased on 15 December; there were 152 explosions during 13-17 December. Eruption plumes rose as high as 1.2 km above the crater rim and bombs were ejected 800 m from the vent. There were 288 explosions recorded during 17-20 December. Resulting plumes rose as high as 1.9 km above the crater rim and bombs were ejected as far as 800 m from the vent. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Yasur
The Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur increased at around 2100 on 18 December. Thirty minutes later webcam images showed deposits of incandescent volcanic bombs that had been ejected from the crater and landed on the flanks. Ash-and-gas plumes were visible at 1015, 1430, and 1545 on 19 December drifting W. The Alert Level remained at 2 (on a scale of 0-4).
Source: Vanuatu Meteorology and Geohazards Department (VMGD)