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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 14 May-20 May 2025
Name Country Volcanic Region Eruption Start Date Report Status
Bezymianny Russia Eastern Kamchatka Volcanic Arc 2024 Dec 24 New
Kanlaon Philippines Negros-Sulu Volcanic Arc 2024 Oct 19 New
Klyuchevskoy Russia Eastern Kamchatka Volcanic Arc 2025 Apr 8 New
Lewotobi Indonesia Sunda Volcanic Arc 2023 Dec 23 New
Raung Indonesia Sunda Volcanic Arc New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Dukono Indonesia Halmahera Volcanic Arc 1933 Aug 13 Continuing
Etna Italy Sicily Volcanic Province 2022 Nov 27 Continuing
Great Sitkin United States Aleutian Ridge Volcanic Arc 2021 May 25 Continuing
Ibu Indonesia Halmahera Volcanic Arc 2008 Apr 5 Continuing
Karymsky Russia Eastern Kamchatka Volcanic Arc 2025 Apr 30 Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group 2024 Dec 23 Continuing
Lewotolok Indonesia Sunda Volcanic Arc 2025 Jan 16 Continuing
Manam Papua New Guinea Bismarck Volcanic Arc 2018 May 10 ± 10 days Continuing
Marapi Indonesia Sunda Volcanic Arc 2023 Dec 3 Continuing
Merapi Indonesia Sunda Volcanic Arc 2020 Dec 31 Continuing
Nevado del Ruiz Colombia Northern Andean Volcanic Arc 2014 Nov 18 Continuing
Ontakesan Japan Nankai Volcanic Arc Continuing
Poas Costa Rica Central America Volcanic Arc 2025 Jan 5 Continuing
Reventador Ecuador Northern Andean Volcanic Arc 2008 Jul 27 Continuing
Sangay Ecuador Northern Andean Volcanic Arc 2019 Mar 26 Continuing
Semeru Indonesia Sunda Volcanic Arc 2017 Jun 6 Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
Suwanosejima Japan Ryukyu Volcanic Arc 2004 Oct 23 Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 21,328 individual reports over 1,272 weeks (average of 17 per week) on 339 different volcanoes.

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Adams Cotopaxi Ijen Lewotobi Peuet Sague St. Helens
Agung Cuicocha Iliamna Lewotolok Pinatubo Stromboli
Ahyi Cumbal Iliwerung Little Sitkin Planchon-Peteroa Sulu Range
Aira Dabbahu Inielika Llaima Poas Sumbing
Akan Davidof Ioto Lokon-Empung Popocatepetl Sumisujima
Alaid Dempo Irazu Lonquimay Purace Sundoro
Alu-Dalafilla Descabezado Grande Iwatesan Lopevi Puyehue-Cordon Caulle Suoh
Ambae Dieng Volcanic Complex Iya Machin Rabaul Suretamatai
Ambang Dukono Izu-Torishima Makushin Raikoke Suwanosejima
Ambrym East Epi Jackson Segment Maly Semyachik Ranakah Taal
Anatahan Ebeko Kaba Manam Raoul Island Tair, Jebel at
Aniakchak Ebulobo Kadovar Manda Hararo Rasshua Takawangha
Antillanca Volcanic Complex Edgecumbe Kaitoku Seamount Marapi Raung Talang
Antuco Egon Kama'ehuakanaloa Maroa Redoubt Tambora
Apoyeque Ekarma Kambalny Martin Reventador Tanaga
Arenal Eldey Kanaga Masaya Reykjanes Tandikat-Singgalang
Asamayama Erebus Kanlaon Matthew Island Rincon de la Vieja Tangkoko-Duasudara
Askja Erta Ale Karangetang Maule, Laguna del Rinjani Tangkuban Parahu
Asosan Etna Karkar Mauna Loa Ritter Island Tara, Batu
Atka Volcanic Complex Etorofu-Yakeyama [Grozny Group] Karthala Mayon Rotorua Ta'u
Augustine Eyjafjallajokull Karymsky McDonald Islands Ruang Taupo
Avachinsky Fagradalsfjall Kasatochi Melebingoy Ruapehu Telica
Awu Fentale Katla Melimoyu Ruby Tenerife
Axial Seamount Fernandina Katmai Merapi Ruiz, Nevado del Tengger Caldera
Azul, Cerro Fogo Kavachi Midagahara Sabancaya Three Sisters
Azumayama Fonualei Kelimutu Misti, El Sakar Tinakula
Bagana Fournaise, Piton de la Kelud Miyakejima Salak Tofua
Balbi Fourpeaked Kerinci Momotombo San Cristobal Tokachidake
Bamus Fuego Ketoi Monowai San Miguel Tolbachik
Banda Api Fujisan Kharimkotan Montagu Island San Vicente Toliman
Bardarbunga Fukutoku-Oka-no-Ba Kick 'em Jenny Moyorodake [Medvezhia] Sangay Tongariro
Barren Island Galeras Kie Besi Mutnovsky Sangeang Api Trident
Batur Galunggung Kikai Myojinsho Santa Ana Tungurahua
Bezymianny Gamalama Kilauea Nabro Santa Maria Turrialba
Bogoslof Gamkonora Kirishimayama Negra, Sierra Sao Jorge Ubinas
Brava Gareloi Kita-Ioto Negro, Cerro Sarigan Ugashik-Peulik
Bristol Island Gaua Kizimen Nightingale Island Sarychev Peak Ukinrek Maars
Bulusan Gede Klyuchevskoy Nishinoshima Saunders Ulawun
Calbuco Gorely Kolokol Group Nisyros Savo Unnamed
Callaqui Great Sitkin Kolumbo Northern EPR at 9.8°N Semeru Unnamed
Cameroon Grimsvotn Koryaksky Novarupta Semisopochnoi Veniaminof
Campi Flegrei Guagua Pichincha Krakatau NW Rota-1 Seulawah Agam Villarrica
Campi Flegrei del Mar di Sicilia Guallatiri Krummel-Garbuna-Welcker Nyamulagira Sheveluch Vulcano
Cayambe Guntur Krysuvik-Trolladyngja Nyiragongo Shishaldin West Mata
Chachadake [Tiatia] Hachijojima Kuchinoerabujima Ofu-Olosega Simbo Westdahl
Chaiten Hakoneyama Kurikomayama Okataina Sinabung Whakaari/White Island
Chiginagak Heard Kusatsu-Shiranesan Okmok Sinarka Witori
Chikurachki Hekla Kverkfjoll Ontakesan Siple Wolf
Chiles-Cerro Negro Helgrindur La Palma Oraefajokull Sirung Wrangell
Chillan, Nevados de Hierro Lamington Osorno Slamet Yakedake
Chirinkotan Hokkaido-Komagatake Lamongan Pacaya Snaefellsjokull Yasur
Chirpoi Home Reef Langila Pagan Soputan Yellowstone
Ciremai Hood Lanin Palena Volcanic Group Sorikmarapi Yufu-Tsurumi
Cleveland Huaynaputina Lascar Paluweh Sotara Zaozan [Zaosan]
Colima Hudson, Cerro Late Panarea Soufriere Hills Zavodovski
Colo Huila, Nevado del Lateiki Papandayan Soufriere St. Vincent Zhupanovsky
Concepcion Hunga Tonga-Hunga Ha'apai Lengai, Ol Doinyo Pavlof South Sarigan Seamount Zubair Group
Copahue Ibu Leroboleng Pelee Spurr
 News Feeds and Google Placemarks


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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 Bezymianny
The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a thermal anomaly over Bezymianny was identified in satellite images during 8-15 May. According to the Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS), crater incandescence was visible during dark hours on some days when weather clouds did not obscure views. Hot avalanches of material descended the flanks on 12 May. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Dates are reported in UTC; specific events are in local time where noted.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS)
Report for Kanlaon
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that the five-minute eruption at Kanlaon on 13 May consisted of two successive ejections of incandescent material and an ash plume that rose possibly as high as 8 km above the crater rim; pyroclastic density currents descended the S flanks as far as 2 km. Ashfall impacted a total of 51 barangays in nine municipalities (four provinces). Sulfur dioxide emissions averaged 5,241 tonnes per day (t/d) that day. Satellite analysis indicated extensive drift of sulfur dioxide across the Philippines, Palawan Island, and N Borneo.

Activity continued during 14-20 May. Gas-and-steam plumes with occasional ash content drifted W and SW on 14 May. Diffuse gas-and-steam plumes rose as high as 100 m above the summit and drifted NW, W, and SW during the rest of the week. The seismic network recorded 2-16 daily volcanic earthquakes. Daily sulfur dioxide emissions ranged from 852 to 2,533 tonnes per day. The Alert Level remained at 3 (on a scale of 0-5); the public was warned to stay 6 km away from the summit and pilots were warned not to fly close to the volcano.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Klyuchevskoy
The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a thermal anomaly at Klyuchevskoy was periodically identified in satellite images during 8-15 May. The Aviation Color Code remained at Yellow (the second lowest 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 Lewotobi
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Lewotobi Laki-laki continued during 12-20 May, with a larger eruption on 18 May. White steam-and-gas plumes rose 50-800 m above the crater rim and drifted in various directions during 14 and 16-17 May. White-and-gray plumes rose as high as 300 m above the summit and drifted SW and W on 15 May. At 0120 on 18 May a gray ash plume rose 900 m above the summit and drifted SW and S.

A period of continuous ash, steam, and gas emissions began at around 1149 on 18 May with a dense gray ash plume that rose 800 m above the summit and drifted N. Dense ash emissions continued through the day and rumbling and banging was heard at the nearest observation post. The ash plume rose to 2 km by 1209 and 3 km by 1218, drifting N and NE. During 1246-1323 the ash plume was as high as 3.5 km above the summit and began drifting also NW. By 1405 the plume had risen to 6 km above the summit and expanded NE, N, NW, W, and SW. The plume was lower at 1430, rising to 4 km and drifting N, NW, and W. Hazy conditions due to ash in the air, possibly mixed with weather clouds based on webcam views prevented visual observations at 1527 and 1614. A dense ash plume rose to 2 km above the summit and drifted NW at 1637. At 2000 PVMBG raised the Alert Level to 4 (on a scale of 1-4). The public was warned to stay 6 km away from the center of Laki-laki and 7 km in a semicircle clockwise from the W to the NE.

At 0008 on 19 May a dense gray ash plume rose 1.2 km above the summit and drifted N and NE. Eruptive events were recorded at 0936, at 1248, at 1342, and at 1406, though conditions prevented visual observations. Ash emissions were ongoing during 1437-2149 with ash plumes rising as high as 5 km above the summit and fanning out from the E counterclockwise to the W. Webcam images at 2145 and 2150 showed incandescent material on the upper flanks and at the summit. Ash plumes rose 4 km above the summit at 2152, 1 km above the summit at 2217, and 500 m above the summit at 2315 and drifted W and NW. Incandescence at the summit was visible in corresponding webcam images. Ash plumes rose 500 m and 300 m above the summit at 0209 and 0224, respectively, on 20 May. Incandescence was again visible at the summit in corresponding webcam images.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Raung
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported increasing volcanic activity at Raung on 16 May. At 0551 an observer saw an ash plume rise to around 1,250 m above the summit and drift S to SW. According to the Darwin VAAC the plume had dissipated by 1140 that same day. 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.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Aira
The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano). No eruptive events were recorded during 5-15 May, though inflation continued to be detected in deformation data, notably starting at 2000 on 12 May. Sulfur dioxide emissions were slightly low, averaging 300 tons per day (t/d); the last measurement was 900 t/d on 2 May. Continuous eruptive activity, including seven explosions, began at around 1045 on 15 May and ended at around 0400 on 16 May, producing ash plumes that rose as high has 3 km above the summit and drifted in multiple directions. Large blocks were ejected as far as 1.2 km from the vent. Field observations confirmed notable ashfall on the E part of the island on 15 May and the N side of the island on 16 May. Deformation data showed a period of deflation after explosions on 15 May, then inflation resumed. Eruptive activity occurred intermittently during 16 May through at least 1500 on 19 May; 86 eruptive events and 44 explosions were detected, generating ash plumes that generally rose as high as 2.9 km above the crater and ejecting blocks as far as 900 m from the crater rim. An ash plume from an explosion at 1854 on 18 May rose 3.2 km above the crater rim and rifted SE, and large blocks were ejected as far as 1.2 km from the crater rim. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to be cautious within 2 km of both the Minimadake and Showa craters.
Source: Japan Meteorological Agency (JMA)
Report for Dukono
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 14-20 May. Daily white-and-gray or white, gray, and black gas-and-ash plumes rose 600-1,500 m above the summit and drifted N, NE, E, and SE. The emissions were continuous most of the day on 14 May, during approximately 0517-1703 on 15 May, from about 0803 on 16 May to about 2217 on 19 May, and during the morning of 20 May. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Etna
The Sezione di Catania - Osservatorio Etneo (INGV) reported continuing eruptive activity at Etna’s SE Crater and gas emissions at Bocca Nuova Crater, NE Crater, and Voragine during 12-18 May. Strombolian activity at SE Crater began in the late afternoon of 12 May, though weather clouds obscured visual observations. The activity was visually confirmed at 2030 during a break in the weather clouds. An eruption cloud drifted downwind and caused minor tephra fall along the SE flank reaching the towns of Petrulli and Zafferana Etnea. Two small lava flows descended the S and E flanks of SE Crater, as far as 0.8 km and 1.8 km, respectively.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
Report for Great Sitkin
The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin’s summit crater during 14-20 May. Small daily earthquakes were detected by the seismic network. Weakly elevated surface temperatures consistent with lava effusion were observed in clear satellite views during 16-19 May and steaming from the active vent was observed during 17-18 May. Weather clouds sometimes obscured views of the volcano. A 20 May radar image confirmed that lava was slowly advancing NE. 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 Ibu
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 14-20 May. Daily gray, white-to-gray, or white-to-brown ash plumes rose as high as 1 km above the summit and drifted in various directions. Nighttime crater incandescence was visible in some webcam images. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karymsky
The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that, in general, moderate explosive activity continued at Karymsky during 8-15 May. Ash clouds were identified in satellite images drifting as far as 250 km SE and NE during 10-11 May. A thermal anomaly over the volcano was identified during 11-15 May; weather clouds obscured views on other days. 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 Kilauea
The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, from two vents along the SW margin of Halema’uma’u Crater, continued at variable levels during 14-20 May. Incandescence at both the N and S vents was visible during 13-16 May, and occasional spattering at the N vent occurred during the evening of 14 May. Small, sporadic, “gas-piston” events that produced spatter fountains and short lava flows began at the N vent at 2245 on 15 May. Five more “gas-piston” events and lava flows occurred the next morning at 0030, 0100, 0125, 0154, and 0243 on 16 May. Dome fountains overflowed the crater at 0440, and sustained high fountaining began at 0513. Fountain heights peaked at 300 m around 0600, then began to oscillate between 100 and 150 m. By 0610 the fountains were producing multiple lava flows that covered about 30-40 percent of the crater floor. The gas plume rose as high as 3 km and drifted WSW, away from populated areas. Sulfur dioxide emission rates were expected to be similar to those recorded during other moderate-to-high fountaining episodes, or around 50,000 tonnes per day (t/d). After over 10 hours of high fountains, that activity ceased at 1529 after an estimated 3.8 million cubic meters of lava had been erupted.

Incandescence from the lava flows was visible near the active vent region and along the N margin of the crater floor overnight during 16-17 May, and incandescence at both the N and S vents was visible during 16-20 May. 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 Hawaiian Volcano Observatory (HVO)
Report for Lewotolok
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 14-20 May. Daily white steam-and-gas plumes rose as high as 100 m above the summit of the cone and drifted NW and W. A nighttime webcam image on 15 May showed incandescence at the summit. At 0751 on 19 May a gray ash plume rose around 500 m above the summit and drifted NW. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Manam
The Darwin Volcanic Ash Advisory Centre (VAAC) reported that an ash plume from Manam was identified in a satellite image at 1020 on 16 May drifting SE. The plume had dissipated by 1220.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Marapi
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity from Verbeek Crater at Marapi (on Sumatra) continued during 14-20 May, characterized by occasional dense gray ash plumes. The tallest ash plume rose 1.6 km above the crater rim at 0942 on 14 May and drifted NE. At 1939 on 15 May an ash plume rose 800 m and drifted E. Ash plumes at 0947 and 0954 on 17 May rose 1 km and 600 m above the crater rim, respectively, and drifted N and NE. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Merapi
The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 9-15 May. Seismicity remained at high levels. The SW lava dome produced 43 lava avalanches that traveled as far as 2 km SW down the Bebeng drainage, 18 that traveled as far as 2 km SW down the Krasak drainage, and 32 that traveled as far as 2 km W down the Sat/Putih drainage. Small morphological changes to the SW lava dome resulted from continuing effusion and minor collapses of material. The hottest temperature was 247.4 degrees Celsius, and the volume of the dome increased by 71,200 cubic meters to an estimated 3,996,800 cubic meters, based on webcam images and a 12 May drone survey. The size of the central dome had not changed; the highest temperature decreased three degrees to 218 degrees Celsius. 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 Nevado del Ruiz
The Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that eruptive activity at Nevado del Ruiz continued during 13-19 May. Seismic data indicated that events associated with fluid movement decreased in both number and intensity compared to the previous week. Seismicity associated with rock fracturing increased in both number and intensity compared to the previous week. The earthquakes were mainly located below Arenas Crater and the NE and SW flanks within 12 km at depths of 1-7 km. Seismicity indicating growth of the lava dome remained at low levels. Low-energy thermal anomalies on the crater floor were identified in satellite data, though weather clouds often obscured views. Significant sulfur dioxide emissions continued to be detected in satellite data. Gas-and-steam plumes rose as high as 500 m above the summit and drifted NW, WNW, and W. The only confirmed gas-and-ash plume during the week rose 700 m above the summit at 0837 on 17 May. The Alert Level remained at Yellow (the second level on a four-level scale).
Source: Servicio Geológico Colombiano (SGC)
Report for Ontakesan
Escalating seismicity coupled with minor inflation at Ontakesan in January caused the Japan Meteorological Agency (JMA) to raise the Alert Level to 2 (on a scale of 1-5). Beginning in February deformation stagnated and only a few volcanic earthquakes were recorded by the seismic network through 20 May. The Alert Level was lowered to 1 at 1100 on 20 May.
Source: Japan Meteorological Agency (JMA)
Report for Poas
The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported continuing gas-and-steam emissions that occasionally contained ash at Poás during 14-20 May. Activity generally decreased during the week, and deformation data indicated deflation. Vigorous gas-and-steam emissions continued at Boca A and incandescence was visible at night. Water that had pooled at Boca C continued to bubble; torrential rains during the beginning of the week continued to fill the crater. A moderate phreatic eruption at 0408 on 18 May generated a gas-and-steam plume with minor amounts of ash that rose 1 km above the crater rim and drifted SW. Sulfur dioxide emissions detected in satellite data were estimated to be 650 tons per day (t/d) on 18 May, 350 t/d on 19 May, and 598 t/d on 20 May. The volcano’s Alert Level remained at 3 (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest color on a four-color scale).
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Reventador
The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 13-20 May. Seismicity included 68-106 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Multiple daily ash-and-gas plumes rose 200-2,000 m above the crater rim and drifted in multiple directions. Webcams recorded multiple nightly instances of incandescent material descending the flanks as far as 1.1 km below the crater rim, specifically down the ESE and SE flanks during 17-18 May. Weather clouds occasionally obscured views. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Orange (the second highest level on a four-color scale).
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Sangay
The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported high levels of eruptive activity at Sangay during 13-20 May. The seismic network recorded 98-194 daily explosions. Ash-and-gas plumes were observed in webcam and/or satellite images on most days rising as high as 2 km above the summit and drifting in multiple directions. Weather clouds often obscured observations, especially during the first half of the week. Crater incandescence was sometimes visible during dark hours from 17 May through 20 May. Incandescent avalanches of material descended the SE flank 600 m during 18-19 May. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Yellow (the second highest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Secretaría de Gestión de Riesgos (SGR)
Report for Semeru
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 14-20 May, with multiple daily eruptive events recorded by the seismic network. Daily white-and-gray or gray ash plumes rose 300-1,000 m above the summit and drifted in multiple directions. The Alert Level remained at 2 (the second lowest level 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
The Kamchatkan Volcanic Eruption Response Team (KVERT) and the Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) reported that lava extrusion may have continued at Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 8-15 May. Thermal anomalies over the domes were identified in satellite images almost daily; weather clouds sometimes obscured views. 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.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS)
Report for Suwanosejima
The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 15-19 May. Incandescence was observed nightly in webcam images. No explosions were detected, though plumes from eruptive events rose 1 km above the crater rim. The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to be cautious within 1.5 km of the crater.
Source: Japan Meteorological Agency (JMA)