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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 10 September-16 September 2025
Name Country Volcanic Region Eruption Start Date Report Status
Akan Japan Kuril Volcanic Arc — New
Kanlaon Philippines Negros-Sulu Volcanic Arc 2024 Oct 19 New
Lokon-Empung Indonesia Sangihe Volcanic Arc — New
Sabancaya Peru Central Andean Volcanic Arc — New
Taal Philippines Luzon Volcanic Arc — New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Dukono Indonesia Halmahera Volcanic Arc 1933 Aug 13 Continuing
Great Sitkin United States Aleutian Ridge Volcanic Arc 2021 May 25 Continuing
Ibu Indonesia Halmahera Volcanic Arc 2008 Apr 5 Continuing
Katmai United States Alaska Peninsula Volcanic Arc — Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group 2024 Dec 23 Continuing
Kirishimayama Japan Ryukyu Volcanic Arc 2025 Jun 22 Continuing
Krasheninnikov Russia Eastern Kamchatka Volcanic Arc 2025 Aug 2 Continuing
Lewotobi Indonesia Sunda Volcanic Arc 2023 Dec 23 Continuing
Lewotolok Indonesia Sunda Volcanic Arc 2025 Jan 16 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
Ranakah Indonesia Sunda Volcanic Arc — 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 2019 Feb 24 Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
St. Helens United States High Cascades Volcanic Arc — 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 21,748 individual reports over 1,289 weeks (average of 17 per week) on 343 different volcanoes.

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


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


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

 Criteria & Disclaimers

Criteria



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

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

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

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

Disclaimers



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

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

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

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

5. USGS Disclaimer Statement for this Website:

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

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

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

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

 Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

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

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

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

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

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

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

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

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

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

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

OFDA - Office of US Foreign Disaster Assistance

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

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

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

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)

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Report for Akan
The Japan Meteorological Agency (JMA) reported increasing unrest at Me-Akan (also known as Meakan-dake, which means Meakan Peak) of the Akan volcanic complex during 11-15 September. The number of small-amplitude volcanic earthquakes with epicenters near Ponmachineshiri Crater began to increase at around 1500 on 11 September and remained elevated during the week with daily counts of 19-50 events. A large tilt change in the direction of the crater was detected at 1440 on 12 September, followed by a period of volcanic tremor during approximately 1440-1447. Tilt continued at a lower rate through 15 September. At around 1800 on 12 September, the typical white steam-and-gas plumes at 96-1 Crater within Ponmachineshiri became more voluminous and taller, rising to 100 m above the crater rim and drifting N, NE, and E. The plumes remained voluminous on 12, 13, and 15 September; weather conditions obscured views on 14 September. Increased thermal activity at the crater was confirmed based on field observations on 15 September. At 1520 on 15 September the Alert Level was raised to 2 (the second lowest level on a 5-level scale) and the public was warned to exercise caution within 500 m of Ponmachineshiri Crater. During an overflight on 16 September scientists confirmed that the vigorous steam-and-gas plumes were rising 200 m above 96-1 Crater and there were proximal ash deposits, mainly to the N. No significant changes were detected in the ground surface temperatures around 96-1 Crater.
Source: Japan Meteorological Agency (JMA)
Report for Kanlaon
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing unrest and an ash emission at Kanlaon during 9-16 September. Daily gas-and-steam emissions of variable densities rose 300-900 m above the crater rim and drifted E, NW, W, and SW. Daily sulfur dioxide emissions ranged from 1,031 to 2,338 tonnes per day (t/d); the average was 2,594 t/d in 2025. A 20-minute-long ash emission began at 0510 on 10 September and produced ash plumes that rose 600 m and drifted WSW. A total of 41 volcano-tectonic (VT) earthquakes were detected from 2200 on 13 September to 1000 on 14 September that were located at depths of 0-7 km beneath the NW flank. The strongest events were classified at Intensity III and felt in La Carlota City (14 km W), Bacolod City (35 km NW), and Canlaon City (10 km ESE), Negros Oriental, as well as in Bago City (30 km NW), Murcia (17 km NNW), and La Castellana (16 km SW), Negros Occidental. During 0000-0800 on 15 September the seismic network recorded 72 VT earthquakes located at depths of 0-12 km. The events were 0.8-3.6 local magnitudes. The strongest events were classified at Intensity I and felt in La Carlota City and Canlaon City. The Alert Level remained at 2 (on a scale of 0-5); the public was warned to stay out of the 4-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Lokon-Empung
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported continuing unrest at Lokon-Empung during 10-16 September. Seismicity continued to be elevated. Daily white steam-and-gas plumes rose as high as 150 m above the Tompaluan Crater rim and drifted in multiple directions. Incandescence at the crater was visible in a few nighttime webcam images. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 2.5 km away from Tompaluan Crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Sabancaya
The Instituto Geofísico del Perú’s (IGP) Centro Vulcanológico Nacional (CENVUL) reported that at 1625 on 13 September an explosion at Sabancaya generated an ash plume that rose 5 km above the crater rim and drifted at least 20 km W, S, and SE. Pyroclastic flows descended the NW, N, and NE flanks as far as 1.6 km. Sulfur dioxide emissions were at low levels, averaging 218 tons per day, and no thermal anomalies were identified. The Alert Level was raised to Orange (the second highest level on a four-color scale) on 13 September and the public was warned to stay outside of a 12 km radius from the summit.
Source: Instituto Geofísico del Perú (IGP)
Report for Taal
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported eruptive activity at Taal during 9-16 September. The seismic network recorded 1-9 daily periods of volcanic tremor ranging from two minutes up to almost 29 hours. There were 5-10 daily volcanic earthquakes that included the volcanic tremor signals during 9-13 September, though no volcanic earthquakes were recorded on 14 September. Daily gas-and-steam emissions with variable densities rose 600-1,200 m above the crater rim and drifted SW. Sulfur dioxide emissions averaged 1,749 tonnes per day (t/d) on 9 September and 1,456 t/d on 11 September. One minor phreatic event occurred on 11 September and lasted for two minutes. Volcano Island (TVI) was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain prohibited. Pilots were warned to avoid flying over TVI.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Aira
The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano) during 8-15 September. Nightly crater incandescence was visible in webcam images. Small eruptive events were occasionally recorded. Sulfur dioxide emissions were characterized as high, averaging 2,800 tons per day on 8 September. 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 9-16 September. Daily white-and-gray gas-and-ash plumes rose as high as 1 km above the summit and drifted in multiple directions. 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 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 9-16 September. Satellite data indicated that the flow was advancing at a rate of about 5 m per day near the vent, with some rockfalls occurring along the S and E margins. The SE half of the lava dome continued to slightly inflate. Small daily earthquakes were detected by the seismic network, including signals probably caused by the small rockfalls. Weather clouds sometimes obscured satellite and webcam views; elevated surface temperatures were identified in satellite data during 9-10 September. 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 10-16 September. Daily dense gray or white-and-gray ash plumes rose 300-600 m above the summit and drifted in multiple directions. Incandescence at the summit was visible in a few nighttime webcam images. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Katmai
The Alaska Volcano Observatory (AVO) reported that on 11 September strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes dispersed unconsolidated ash up to 1.2 km (4,000 ft) a.s.l. to the SE. The ash was originally deposited during the Novarupta-Katmai eruption in 1912. The Volcano Alert Level remained at Normal (the lowest level on a four-level scale) and the Aviation Color Code remained at Green (the lowest level on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Kilauea
The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, characterized by episodic fountaining, incandescence, and intermittent spatter from craters along the SW margin of Halema’uma’u Crater, continued at variable levels during 9-16 September. Patterns of tremor indicated that gas pistoning (a shallow, gas-driven rise and fall of a lava surface) was likely occurring deeper within the vent, producing low-frequency seismic bursts every 3-8 minutes during 9-13 September. Elevated levels of gas continued to be emitted from the vent area; average sulfur dioxide emission rates during pauses in lava fountaining were typically 1,200 to 1,500 tonnes per day, though rates varied on short timescales in association with gas pistoning. Incandescence was visible at both the N and S vents overnight during 15-16 September. 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 Kirishimayama
The Japan Meteorological Agency (JMA) reported that activity continued at Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group) during 8-15 September. The number of volcanic earthquakes located beneath Shinmoedake, first detected in late October 2024, continued to be frequent; volcanic tremor was last detected on 4 September. Gas-and-steam plumes rose as high as 500 m above the crater rim and fumarolic plumes rose as high as 20 m along the fissures on the W flank. Sulfur dioxide emissions were low on 12 September, averaging 300 tons per day. The Alert Level remained at 3 (on a 5-level scale) and the public was warned to exercise caution within 3 km from Shinmoedake Crater.
Source: Japan Meteorological Agency (JMA)
Report for Krasheninnikov
The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that the eruption at Krasheninnikov continued during 5-11 September. A thermal anomaly over the volcano was identified in satellite images during 4, 7-9, and 11 September; weather clouds obscured views on the other days. Dates and times are provided in Coordinated Universal Time (UTC); specific events are indicated in local time where specified.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Lewotobi
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported decreased surficial activity and lower levels of seismicity at Lewotobi Laki-laki during 9-16 September. White steam-and-gas plumes with variable densities rose as high as 700 m above the summit and drifted in various directions. Diffuse steam-and-gas plumes rose from fracture zones on the upper NW and NE flanks. Eight avalanches of material were seismically detected but not visually observed. Seismic levels fluctuated and were dominated by non-harmonic tremors; other types of seismic signals were at lower levels compared to the previous week. At 1500 on 16 September the Alert Level was lowered to 3 (on a scale of 1-4) and the public was warned to stay 6 km away from the center of Laki-laki.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Lewotolok
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 10-16 September. Daily white-to-gray ash plumes rose 200-800 m above the summit of the cone and drifted W and NW. Several nighttime webcam images showed Strombolian ejections of incandescent material above the cone and onto the flanks. 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.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Marapi
The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi (on Sumatra) continued during 10-16 September. Almost daily white steam-and-gas plumes rose as high as 200 m above the crater rim and drifted in multiple directions. Eruptive events were recorded at 2205 on 11 September and at 0823 on 16 September, but weather conditions prevented visual confirmation. 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 5-11 September. Earthquakes were more intense compared to the previous week. The SW lava dome produced 11 lava avalanches that traveled as far as 1.9 km SW down the Bebeng drainage, 25 that traveled as far as 2 km SW down the Krasak drainage, 47 that traveled as far as 2 km W down the Sat/Putih drainage, and one that descended the Boyong drainage on the S flank as far as 1.8 km. Small morphological changes to the SW lava dome resulted from lava effusion and minor collapses. 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 Kegunungapian (BPPTK)
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 9-15 September, though weather conditions sometimes obscured visual observations. Seismic data indicated that events associated with fluid movement decreased in number but increased in intensity compared to the previous week, though levels were low-to-moderate overall. Some of the seismic events were associated with pulsating ash emissions, including some with higher-temperature ejecta. Gas, steam, and ash emissions generally rose as high as 400 m above the summit and mainly drifted NW, though some plumes drifted WNW, W, and WSW. A few plumes rose to 1 km above the summit, but the highest plume rose to 1.5 km above the summit at 0821 on 14 September. Seismicity associated with rock fracturing decreased in both number and intensity compared to the previous week. The earthquakes were mainly located at depths of 1-8 km below Arenas Crater and the flanks within 10 km. Daily sulfur dioxide emissions were similar to the previous week. Low-level thermal anomalies at the bottom of the crater were periodically identified in satellite images. The Alert Level remained at Yellow (the second level on a four-level scale).
Source: Servicio Geológico Colombiano (SGC)
Report for Ranakah
At 1100 on 17 September the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) lowered the Alert Level for Ranakah to 1 (on a scale of 1-4) noting decreased seismicity. The numbers of both of deep volcanic earthquakes and low-frequency earthquakes had increased in December 2024 but since then seismicity decreased, specifically the number of deep volcanic earthquakes. No changes at the lava dome had been observed. The public was warned to stay away from the active crater area.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Reventador
The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 9-16 September. Seismicity included 67-108 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Ash-and-gas plumes visible in webcam and/or satellite images on most days rose as high as 1.4 km above the crater rim and drifted mainly NW, W, and SW. Webcams recorded multiple nightly instances of incandescent material descending the flanks as far as 1.1 km below the crater rim. Cloudy weather occasionally obscured views. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Orange (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 Sangay
The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that the eruption continued at Sangay during 9-16 September. The seismic network recorded 34-85 explosions each day. Ash-and-gas plumes were observed on most days in webcam and/or satellite images rising as high as 1.5 km above the summit and drifting NW, W, and SW, though weather clouds often obscured views. A small thermal anomaly at the crater was visible overnight during 13-14 September. 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 10-16 September, with multiple daily eruptive events recorded by the seismic network. White-and-gray or gray ash plumes rose 300-800 m above the summit and drifted in multiple direction on most days; emissions were not visible on 10 or 16 September. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 3 km away from the summit in all directions, 8 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 13 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) reported continuing eruptive activity at Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 5-11 September. Thermal anomalies over the domes were identified in satellite images during 7-10 September; weather clouds obscured views on the other days. An ash plume drifted 72 km SE on 8 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for St. Helens
The Cascades Volcano Observatory (CVO) reported that on 16 September strong winds in the vicinity of Mount St. Helens dispersed unconsolidated ash to the WNW. The resuspended ash was reported by commercial pilots in the area. The ash was originally deposited during the 1980 eruptions. The Volcano Alert Level remained at Normal (the lowest level on a four-level scale) and the Aviation Color Code remained at Green (the lowest level on a four-color scale).
Source: US Geological Survey Cascades Volcano Observatory (CVO)
Report for Suwanosejima
The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 8-15 September. Incandescence was observed nightly in webcam images. Eruptive events during 11-12 and 14-15 September generated ash plumes that rose 1.3-1.7 km above the crater rim and drifted E, NE, E, and NW. Large blocks were occasionally ejected as high as 100 m above the vent. Volcanic earthquakes, likely located beneath the W side of the island, had been increasing since October 2024. An earthquake at 1239 on 12 September was felt at the observation post in Toshima Village (3.5 km SSW) and classified as an Intensity I event. 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)