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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 30 August-5 September 2023
Name Location Eruption Start Date Report Status
Villarrica Central Chile 2014 Dec 2 ± 7 days New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Dukono Halmahera 1933 Aug 13 Continuing
East Epi Vanuatu Continuing
Ebeko Paramushir Island (Russia) 2022 Jun 11 Continuing
Great Sitkin Andreanof Islands (USA) 2021 May 25 Continuing
Ibu Halmahera 2008 Apr 5 Continuing
Karangetang Sangihe Islands 2018 Nov 25 Continuing
Klyuchevskoy Central Kamchatka (Russia) 2023 Jun 22 Continuing
Lewotolok Lembata Island 2020 Nov 27 Continuing
Mayon Luzon (Philippines) 2023 Apr 27 ± 2 days Continuing
Merapi Central Java 2020 Dec 31 Continuing
Popocatepetl Mexico 2005 Jan 9 Continuing
Reventador Ecuador 2008 Jul 27 Continuing
Rincon de la Vieja Costa Rica 2021 Jun 28 Continuing
Sangay Ecuador 2019 Mar 26 Continuing
Semeru Eastern Java 2017 Jun 6 Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Shishaldin Fox Islands (USA) 2023 Jul 12 Continuing
Suretamatai Banks Islands (Vanuatu) Continuing
Suwanosejima Ryukyu Islands (Japan) 2004 Oct 23 Continuing
Ubinas Peru 2023 Jun 22 Continuing
Yasur Vanuatu 1270 ± 110 years Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,832 individual reports over 1,207 weeks (average of 16 per week) on 332 different volcanoes.

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


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



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

 Criteria & Disclaimers

Criteria



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

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

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

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

Disclaimers



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

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

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

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

5. USGS Disclaimer Statement for this Website:

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

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

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

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

 Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

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

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

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

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

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

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

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

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

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

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

OFDA - Office of US Foreign Disaster Assistance

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

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

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

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)

Report for Villarrica
SERNAGEOMIN reported that a long-period earthquake recorded at 1643 on 2 September was accompanied by a minor ash plume that rose to 180 m above Villarrica’s summit crater rim and dispersed SE. According to the Buenos Aires VAAC, periods of continuous gas-and-ash emissions were visible in webcam images from 1830 on 2 September to 0110 on 3 September. POVI reported that the lava lake was active and during 3-4 September lava fountaining was visible for the first time since 26 March. Fountains captures in webcam images at 2133 on 3 September and 0054 on 4 September rose as high as 60 m above the crater rim and ejected material onto the upper W flank. The Volcanic Alert level remained at Yellow (the second highest on a four-level scale) according to SERNAGEOMIN and the public was warned to stay 500 m away from the crater. SENAPRED maintained the Alert Level at Yellow (the middle level on a three-color scale) for the communities of Villarrica, Pucón (16 km N), Curarrehue, and Panguipulli.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Sistema y Servicio Nacional de Prevención y Repuesta Ante Desastres (SENAPRED), Proyecto Observación Villarrica Internet (POVI), Buenos Aires Volcanic Ash Advisory Center (VAAC)
Report for Aira
JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 28 August-4 September. Incandescence at Minamidake was observed nightly. An explosion at 0640 on 31 August from the same crater ejected large blocks 400 m away and likely produced a plume that was obscured by weather clouds. Very small eruptive events continued to be detected during the rest of the week. A very small eruption at Showa Crater was also recorded on 4 September. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.
Source: Japan Meteorological Agency (JMA)
Report for Dukono
PVMBG reported that the eruption at Dukono was ongoing during 30 August-4 September. Dense white-and-gray plumes rose as high as 400 m above the summit and drifted E, NW, and W during 31 August and 2-5 September; weather conditions sometimes prevented views. The Alert Level remained at Level 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for East Epi
On 31 August the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that minor unrest continued at Epi. Volcanic seismicity was sustained, though no surficial activity was observed. The Alert Level remained at 1 (on a scale of 0-5) and the public was warned to stay outside of the Danger Zone, defined as a 2-km radius around the active vent.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)
Report for Ebeko
KVERT reported that moderate explosive activity at Ebeko was ongoing during 24-31 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 27-31 August generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l and drifted to the E and SE. A thermal anomaly was identified in satellite images during 27 and 29-30 August; 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 Great Sitkin
AVO reported that slow lava effusion continued at Great Sitkin during 30 August-5 September, producing a thick flow in the summit crater that expanded E, based on a satellite image from 30 August and fieldwork. Seismicity was low; two earthquakes were detected during 2-4 September and five were recorded during 4-5 September. An AVO field geology team visited the volcano on 1 September and sampled the lava flow, did airborne photography and thermal imaging surveys, and measured gas emissions. During a visit on 3 September the team observed that the flows were warm and steaming, moving about 1 m every 3-4 days. Weakly elevated surface temperatures were identified in satellite data during 4-5 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
PVMBG reported that Ibu continued to erupt during 30 August-4 September. Daily white-and-gray ash emissions generally rose as high as 800 m above the summit and drifted E, NE, N, and SW. Gray ash plumes rose as high as 1.5 km on 31 August that drifted N and NE, and as high as 1 km on 5 September and drifted W and NW. The Alert Level remained at a 2 (the second highest level on a four-level scale), and the public was advised to stay outside of the 2 km hazard zone, and to stay 3.5 km away from the N area of the active crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karangetang
PVMBG reported that dense white gas-and-steam plumes from Karangetang were visible daily rising as high as 200 m and drifting multiple directions during 30 August-5 September. Weather clouds sometimes prevented views of the summit. According to news articles, incandescent lava avalanches from Main Crater (S crater) traveled as far as 1.5 km down the Batuawang and Kahetang drainages and as far as 1 km down the Batang, Timbelang, and West Beha drainages. Incandescence at the S and N craters continued to be visible. The Alert Level remained at 3 (on a scale of 1-4) and the public were advised to stay 2.5 km away from Main Crater with an extension to 3.5 km on the S and SE flanks.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Antara News, Antara News, Antara News, Antara News
Report for Klyuchevskoy
KVERT reported that the explosive Strombolian eruption at Klyuchevskoy continued during 24-31 August and a daily bright thermal anomaly was identified in satellite images. A plume of ash resuspended by strong winds drifted 95 km E at 3-3.5 km (10,000-11,500 ft) a.s.l., prompting KVERT to raise the Aviation Color Code to Orange (the third level on a four-color scale) at 1240 on 4 September, local time. By 1940 the plume had drifted as far as 170 km E, remining at the same altitudes; the Aviation Color Code was lowered back to Yellow at 1954 (local time). The Aviation Color Code was again raised to Orange for a few hours, during 1532-1808 local time on 5 September, due to plumes of resuspended ash drifting 120 km ENE. KVERT noted that Strombolian activity continued, feeding a lava flow that advanced down the Kozyrevsky drainage on the SW flank. Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 30 August-5 September. Almost daily white steam-and-gas plumes rose as high as 700 m above the summit and drifted W and NW. White-and-gray ash plumes rose as high as 700 m and drifted E, SW, and W on 1 September. A Volcano Observatory Notices for Aviation (VONA) described an ash plume rising 500 m and drifting SE on 3 September; a webcam image showed incandescent material at the crater and on the upper flank. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay at least 2 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Mayon
PHIVOLCS reported that the eruption at Mayon continued during 30 August-5 September, with slow lava effusion from the summit crater feeding flows on the S, SE, and E flanks. The lengths of the lava flow in the Mi-Isi (S), Bonga (SE), and Basud (E) drainages remained at 2.8 km, 3.4 km, and 1.1 km, respectively. Collapses at the lava dome and from the lava flows produced incandescent rockfalls and pyroclastic density currents (PDCs, or pyroclastic flows) that descended the three drainages as far as 4 km. Each day seismic stations recorded 115-196 rockfall events and 1-6 PDC events. There were 2-37 daily volcanic earthquakes; those totals included three tremor events, each with durations of 1-38 minutes, during 1-2 September. Sulfur dioxide emissions were measured on a few days and averaged between 1,673 and 2,247 tonnes per day, with the highest value recorded on 3 September. The Alert Level remained at 3 (on a 0-5 scale) and residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ). PHIVOLCS recommended that civil aviation authorities advise pilots to avoid flying close to the summit.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Merapi
BPPTKG reported that the eruption at Merapi (on Java) continued during 25-31 August and seismicity remained at elevated levels. The SW lava dome produced a total of 118 lava avalanches that descended the S and SW flanks; two traveled as far as 1 km down the upper part of the Boyong drainage, 115 traveled as far as 2.3 km down the upper Bebeng drainage, and one traveled 500 m down the Senowo drainage. Morphological changes to the SW lava dome were due to continuing collapses of material. No changes were observed at the dome in the main crater. 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 Popocatepetl
CENAPRED reported that eruptive activity continued at Popocatépetl during 29 August-4 September. Long-period events totaling 30-99 per day were accompanied by steam-and-gas plumes that sometimes contained minor amounts of ash. Periods of volcanic tremor (20-389 minutes) were recorded daily; low- to medium-amplitude, high-frequency tremor during 31 August-2 September was accompanied by continuous gas-and-steam emissions that contained minor amounts of ash, rose 1-2 km above the crater rim, and drifted WSW. A few volcano-tectonic earthquakes were recorded during 30 August-1 September. Minor and moderate explosions were recorded at 1848 on 30 August, at 0032, 1614, and 1702 on 31 August, at 1524 and 1755 on 1 September, at 0442, 0720, 2221 on 3 September, at 1745 on 4 September, and at 0758, 0859, and 1000 on 5 September. Ashfall was reported in Ozumba (18 km W), Atlautla (16 km W), Tepetlixpa (21 km W), and Ecatzingo (15 km SW) in the State of México and in Cuernavaca (65 km WSW), Temixco (67 km WSW), Huitzilac (67 km W), Tepoztlán (49 km W), and Jiutepec (59 km SW) in the State of Morelos on 1 and 5 September. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Reventador
IG-EPN reported that the eruption at Reventador was ongoing during 29 August-5 September. Seismicity was characterized by 23-48 daily explosions, long-period earthquakes, volcano-tectonic events, harmonic tremor, and tremor associated with emissions. Crater incandescence was visible overnight during 29 August-3 September; incandescent material was sometimes ejected onto the flanks and then descended as far as 500 m. Daily ash-and-gas plumes rose 600-1,000 m above the crater rim and drifted NW, W, and SW. Weather conditions sometimes prevented views of the volcano. Secretaría de Gestión de Riesgos 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 Rincon de la Vieja
OVSICORI-UNA reported that small phreatic events and gas-and-steam emissions continued at Rincón de la Vieja during 29 August-5 September. Three small eruptive events generated steam-and-gas plumes that rose 2-3 km above the crater rim during 28-29 August. Multiple events produced steam-and-gas plumes during 30-31 August. At 1526 on 1 September an eruptive event generated a steam-and-gas plume that rose 2 km above the crater rim and ejected material onto the flanks. Small events were detected in infrasound data during 2-3 September. At 1251 on 4 September a steam-and-gas plume that rose 1 km above the crater rim and drifted W. The Alert Level remained at Level 3, Orange, the third level on a four-level scale.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Sangay
IG-EPN reported a high level of eruptive activity at Sangay during 29 August-5 September, with seismic stations recording 355-723 daily explosions. Nightly webcam images showed incandescent material at the crater, explosions ejecting material above the crater, and incandescent material descending the SE flank as far as 1.8 km. Several ash-and-gas plumes rose as high as 2 km above the crater rim and drifted mainly SW and W each day except for 1 September, when weather clouds prevented views. Secretaría de Gestión de Riesgos 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
PVMBG reported that eruptive activity continued at Semeru during 30 August-5 September. At 0843 and 0916 on 30 August dense gray-to-white ash plumes rose 500-800 m above the summit and drifted NW and SW, respectively. White gas-and-steam emissions rose as high as 100 m above the summit and drifted in variable directions during 1-3 September; weather clouds sometimes hindered views. The Alert Level remained at 3 (third highest on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Sheveluch
KVERT reported that the eruption at Sheveluch continued during 24-31 August. Intense fumarolic activity was visible at the active dome, and daily thermal anomalies were identified in satellite images. A plume of resuspended ash drifted 650 km SE during 30-31 August. Plumes of resuspended ash drifted 110 km E at altitudes of 2.5-3 (8,200-10,000 ft) a.s.l. on 4 September. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Shishaldin
AVO reported that the eruption at Shishaldin continued during 30 August-5 September. Weather conditions sometimes prevented observations. Daily, small, repetitive explosions were recorded in seismic and infrasound data, though high winds occasionally masked the signals. Elevated surface temperatures at the summit were identified in satellite data on most days. Hot deposits on the NE flank, emplaced during 25-26 August, were visible in a 1 September satellite image, along with steam emissions obscuring the summit vent. Possible incandescence at the summit was visible in nighttime webcam images during 3-4 September, and small steam emissions were visible in daytime images.

Seismicity began to gradually increase at around 0300 on 5 September and activity escalated around 0830. A pilot in the vicinity of the volcano reported an ash plume at about 7.6 km (25,000 ft) a.s.l. at 0842 that was continuing to rise. The ash plume was large and may have risen as high as 9.7 km (32,000 ft) a.s.l. and drifted SSE based on satellite images. AVO raised the Aviation Color Code to Red (the highest color on a four-color scale) and the Volcano Alert Level to Warning (the highest level on a four-level scale) at 0901. Seismic amplitude decreased rapidly at around 1100, and remained low, and the altitude of ash emissions observed in satellite images also decreased to an estimated 4.5 km (15,000 ft) a.s.l. By 1200 the lower-altitude portion of the ash plume had drifted 125 km E. Significant ash emissions ended by 1330 based on webcam images. At 1440 AVO lowered the Aviation Color Code to Orange and the Volcano Alert Level to Watch. This event marks the ninth period of elevated eruptive activity resulting in significant ash emissions and mass flows of volcanic debris on the volcano's flanks since the onset of the current eruption.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Suretamatai
On 31 August the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Suretamatai continued at a level of “minor unrest.” No notable volcanic emissions were identified in the most recent satellite data, though steam emissions from areas around the cone and the Sulphur River continued to be locally observed. The public was reminded that the danger zone was near the cone and the Sulphur River, though the risk to the public was low.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)
Report for Suwanosejima
JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 28 August-4 September. Eruptive events produced volcanic plumes that rose as high as 700 m above the crater rim. An eruptive event at 1949 on 4 September produced an ash plume that rose 1 km above the crater rim and drifted SW. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Ubinas
Instituto Geofísico del Perú (IGP) reported that the eruption at Ubinas continued during 28 August-3 September. There were daily averages of 78 volcano-tectonic earthquakes indicating rock fracturing and 42 long-period earthquakes signifying the movement of gas and magma. In addition, seismic signals associated with ash emissions were recorded for an average of 30 minutes per day, with a maximum of 1 hour on 3 September. Webcams recorded ash-and-gas emissions rising as high as 600 m above the crater rim and drifting as far as 5 km E and SE during 28 August-4 September. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay 4 km away from the crater.
Source: Instituto Geofísico del Perú (IGP)
Report for Yasur
On 31 August the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest,” as defined by the Alert Level 2 status (the middle level on a scale of 0-4). Recent satellite observations indicated an increase in steam, gas, and ash emissions from the summit crater. Explosions continued, with some ejecting bombs that landed back in and around the crater. The public was reminded to not enter the restricted area within 600 m around the boundaries of the Permanent Exclusion Zone, defined by Danger Zone A on the hazard map.
Source: Vanuatu Meteorology and Geohazards Department (VMGD)