Logo link to homepage

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 21 November-27 November 2018
Name Location Eruption Start Date Report Status
Fuego Guatemala 2002 Jan 4 New
Karangetang Siau Island (Indonesia) 2018 Nov 25 New
Mayon Luzon (Philippines) New
Suwanosejima Ryukyu Islands (Japan) 2004 Oct 23 New
Veniaminof United States New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Dukono Halmahera (Indonesia) 1933 Aug 13 Continuing
Ebeko Paramushir Island (Russia) 2016 Oct 20 Continuing
Ibu Halmahera (Indonesia) 2008 Apr 5 Continuing
Krakatau Indonesia Continuing
Kuchinoerabujima Ryukyu Islands (Japan) Continuing
Merapi Central Java (Indonesia) 2020 Dec 31 Continuing
Pacaya Guatemala 2015 Jun 7 ± 1 days Continuing
Rincon de la Vieja Costa Rica 2021 Jun 28 Continuing
Sabancaya Peru 2016 Nov 6 Continuing
Sangay Ecuador 2019 Mar 26 Continuing
Santa Maria Guatemala 1922 Jun 22 Continuing
Semisopochnoi Aleutian Islands (USA) 2021 Feb 2 ± 2 days Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Turrialba Costa Rica Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 17,119 individual reports over 1,085 weeks (average of 16 per week) on 316 different volcanoes.

Search by Date



Use the dropdowns to choose the year and week for archived Weekly Reports.

Use the dropdowns to choose the year and week for archived Weekly Reports.          



Search by Volcano



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


Download Smithsonian / USGS Weekly Volcanic Activity Report Network RSS Feed

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.



Download Smithsonian / USGS Weekly Volcanic Activity Report Network CAP Feed

The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.



Download Smithsonian/USGS Weekly Volcanic Activity Report Network Link Download Smithsonian / USGS Weekly Volcanic Activity Report Network Link

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 Fuego
On 23 November INSIVUMEH reported that during the previous few days moderate explosions at Fuego generated shock waves that vibrated structures within 20 km. Ash plumes from the explosions rose 1.3 km above the cone in the summit crater and drifted 20 km W and SW, causing ashfall in areas downwind including Panimaché (8 km SW), El Porvenir (8 km ENE), Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Palo Verde Estate, and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 150 m high, causing avalanches, some that traveled long distances in the Las Lajas (SE), Ceniza (SSW), and Seca (W) drainages and reached vegetated areas. During 24-25 November there were 12-15 weak-to-moderate explosions per hour, generating ash plumes that rose as high as 1.1 km and drifted 20-25 km W and SW. Shock waves continued to vibrate local structures, and ashfall was again reported in Panimaché, El Porvenir, Morelia, Santa Sofia, Sangre de Cristo, Palo Verde Estate, and San Pedro Yepocapa. Moderate-to-strong Vulcanian explosions on 26 November generated ash plumes that rose as high as 1.2 km and drifted N. The explosions were heard, and shock waves felt, mostly within 25 km, though some explosions were audible to residents of Guatemala City (city center is about 40 km ENE). Explosions continued the next day at a rate of 10-15 per hour. Ash plumes rose as high as 1.3 km and drifted 20-25 km W and SW. Incandescent material was ejected 200 m high, and avalanches of material descended multiple drainages. Ashfall was reported in areas downwind.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Coordinadora Nacional para la Reducción de Desastres (CONRED)
Report for Karangetang
PVMBG reported that at 1314 on 25 November an eruption at Karangetang produced an ash plume that rose at least 500 m above the crater rim; weather clouds prevented clear views of the plume. The Aviation Color Code was raised to Orange, though the Alert Level remained at 2 (on a scale of 1-4).
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Mayon
PHIVOLCS reported that during 21-26 November white steam plumes periodically emitted from Mayon rose as high as 750 m and drifted WSW and SW. Crater incandescence was visible at night during 24-27 November. Two phreatic explosions were recorded during 0759 and 0805 on 26 November. The events generated grayish ash plumes that rose 300-500 m and drifted SW. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Suwanosejima
JMA reported that 16 explosions at Suwanosejima’s Ontake Crater were recorded during 16-22 November. The highest ash plume rose 2 km, and material was ejected 300 m from the crater. Ashfall was reported in an area 4 km SSW on 17 November. The Alert Level remained at 2 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Veniaminof
Ash emissions from the cone in Veniaminof’s ice-filled summit caldera significantly increased overnight during 20-21 November, prompting AVO to raise the Aviation Color Code to Red and the Volcano Alert Level to Warning (the highest levels on four-level scales). Ash emissions rose to below 4.6 km (15,000 ft) a.s.l. and drifted more than 240 km SE. On 21 November observers and webcam views in Perryville (35 km SE) indicated continuous ash emissions through most of the day; ash plumes drifted SE, extending as far as 400 km by around 1445. A short eruptive pulse was recorded during 1526-1726, and then afterwards ash plumes rose to below 3 km (10,000 ft) a.s.l. Low-altitude ash emissions on 22 November drifted 100 km S. Minor ashfall was reported in Perryville. AVO lowered the Aviation Color Code and Volcano Alert Level to Orange and Watch, respectively, because of decreased ash emissions. Elevated thermal anomalies were identified in satellite data overnight, and incandescence was visible from a Perryville webcam, suggesting continuing lava effusion which had been obscured by the increased period of ash emissions. Lava effusion was persistent through 27 November.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Aira
JMA reported that four events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) were recorded during 19-22 November, producing ash plumes that rose as high as 1.6 km above the crater rim. Material was ejected 500-700 m from the crater. Occasional, very small events occurred during 22-26 November. Crater incandescence was visible at night during 20-21 November, for the first time since 20 September, and continued through 26 November. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Dukono
Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 21-27 November ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NE, E, and SE.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Ebeko
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 15-23 November that sent ash plumes to 3.2 km (10,500 ft) a.s.l. Ash plumes drifted NE and S. 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 Ibu
The Darwin VAAC reported that on 26 November an ash plume from Ibu was identified in satellite images rising to 1.8 km (6,000 ft) a.s.l. and drifting SE. 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 active crater, and 3.5 km away on the N side.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Krakatau
PVMBG reported that events at Anak Krakatau were recorded at 0611 on 24 November, at 0810 on 25 November, and at 0900 and 1037 on 26 November, each lasting between 30 and 42 seconds. Ash plumes from the events rose 300-600 m and drifted NE and SW; the ash plumes from the 1037 event were dense and black. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Kuchinoerabujima
JMA reported that during 22-26 November intermittent events at Kuchinoerabujima’s Shindake Crater generated plumes that rose as high as 2.1 km above the crater rim. The Alert Level remained at 3 (on a scale of 1-5).
Source: Japan Meteorological Agency (JMA)
Report for Merapi
PVMBG reported that during 16-22 November the lava dome in Merapi’s summit crater grew at a rate of 2,600 cubic meters per day, slower than the previous week. By 21 November the volume of the dome, based on photos taken from the SE, was an estimated 308,000 cubic meters. White emissions of variable density rose a maximum of 125 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Pacaya
INSIVUMEH reported that during 24-27 November Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 25 m above the crater rim. As many as three lava flows were active on the NW flanks, advancing towards Cerro Chino. Minor avalanches of material descended the SE flank during 26-27 November.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Rincon de la Vieja
OVSICORI-UNA reported that at 0237 on 27 November a hydrothermal explosion at Rincón de la Vieja produced a plume of water vapor and gas that rose 600 m above the crater rim and drifted SW.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Sabancaya
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 20 explosions per day occurred at Sabancaya during 19-25 November. Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 2.7 km above the crater rim and drifted 40 km NW and N. MIROVA detected six thermal anomalies, and on 22 November the sulfur-dioxide gas flux was high at 3,000 tons per day. The report noted that the public should not approach the crater within a 12-km radius.
Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET), Instituto Geofísico del Perú (IGP)
Report for Sangay
IG reported that since 8 August activity at Sangay was characterized by the extrusion of lava flows on the ESE flank and ash emissions that rose between 500 and 1,500 m and mainly drifted W and NW. Lava flows were 1-2 km long, though block avalanches from the flow fronts traveled additionally as far as 5 km. The seismic network recorded more than 50 signals per day indicating explosions. The activity continued at least through 21 November; the report noted that this phase has lasted longer than any other since 2015.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Santa Maria
INSIVUMEH reported that during 24-27 November explosions at Santa María's Santiaguito lava-dome complex generated ash plumes that rose 700-900 m and drifted SW, causing ashfall in Monte Claro. Avalanches of material descended the SE and NE flanks of the lava dome.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semisopochnoi
AVO reported that no evidence of activity at Semisopochnoi had been detected since an explosion was recorded in infrasound data on 31 October. The satellite link for transmitting seismic data failed on 1 November, though no activity was observed in satellite or infrasound data since then. As a result, the Aviation Color Code was lowered to Yellow and Volcano Alert Level was lowered to Advisory (both are the second lowest levels on four-level scales) on 21 November.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 16-17 and 19-20 November. 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 Turrialba
OVSICORI-UNA reported that at 0710 on 22 November an event at Turrialba generated an ash plume that rose 100 m above the crater rim and drifted W. The next day there were frequent pulses of ash. During 23-25 November occasional Strombolian explosions ejected lava bombs that were deposited near the crater; residents of Cascajal de Coronado reported hearing several booming sounds. Ash plumes rose as high as 500 m. During 26-27 November passive emissions with small quantities of ash were visible. Minor ashfall was reported in San Jose (Cascajal de Coronado and Dulce Nombre), San Pedro Montes de Oca, and neighborhoods of Heredia.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)