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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 8 September-14 September 2021
Name Location Eruption Start Date Report Status
Askja Iceland New
Fukutoku-Oka-no-Ba Volcano Islands (Japan) 2021 Aug 13 New
La Palma Spain New
Pagan Mariana Islands (USA) New
Whakaari/White Island North Island (New Zealand) New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Cerro Hudson Chile Continuing
Ebeko Paramushir Island (Russia) 2016 Oct 20 Continuing
Great Sitkin Andreanof Islands (USA) 2021 May 25 Continuing
Grimsvotn Iceland Continuing
Ibu Halmahera (Indonesia) 2008 Apr 5 Continuing
Karymsky Eastern Kamchatka (Russia) 2020 Apr 1 Continuing
Krysuvik-Trolladyngja Iceland 2021 Mar 19 Continuing
Langila New Britain (Papua New Guinea) 2015 Oct 22 (?) Continuing
Lewotolok Lembata Island (Indonesia) 2020 Nov 27 Continuing
Merapi Central Java (Indonesia) 2020 Dec 31 Continuing
Nevados de Chillan Chile 2016 Jan 8 Continuing
Pavlof United States 2021 Aug 5 Continuing
Semisopochnoi Aleutian Islands (USA) 2021 Feb 2 ± 2 days Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Suwanosejima Ryukyu Islands (Japan) 2004 Oct 23 Continuing
Taal Luzon (Philippines) Continuing
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 17,021 individual reports over 1,080 weeks (average of 16 per week) on 315 different volcanoes.

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


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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 monthly, and 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 Askja
On 9 September IMO raised the Aviation Color Code for Askja to Yellow, noting that inflation that began in early August was ongoing and notably rapid. The uplift was centered at the W edge of Oskjuvatn caldera, which rose a total of 7 cm. The data suggested that magma was accumulating at 2-3.5 km depth.
Source: Icelandic Meteorological Office (IMO)
Report for Fukutoku-Oka-no-Ba
The Japan Coast Guard reported that during a 12 September overflight of Fukutoku-Oka-no-Ba, observers noted that the W island was unchanged while the E side had been completely eroded and submerged. Yellow-green to yellow-brown discolored water extended from the vent area to the SW, S, and SE, suggesting continuing eruptive activity. Another area of discolored water had an approximate diameter of 2 km and was about 2 km ENE of the volcano. The discolored water prompted JMA to issue a navigation warning to nearby vessels.
Source: Japan Coast Guard
Report for La Palma
Instituto Geográfico Nacional (IGN) and Instituto Volcanológico de Canarias (INVOLCAN) reported that a seismic swarm beneath Cumbre Vieja at the S part of La Palma began at 1618 on 11 September and was likely associated with a magmatic intrusion. The swarm intensified in number of events and magnitude, and by 1600 on 12 September a total of 315 earthquakes had been recorded and ranged 8-13 km in depth. The largest event was a M 2.8 (on the Mb_lg scale). On 13 September a scientific committee comprised of representatives from multiple agencies and institutions raised the Alert Level to Yellow (the second lowest level on a four-color scale) for the municipalities of El Paso, Los Llanos de Aridane, Mazo, and Fuencaliente de la Palma. By 0800 on 14 September 2,935 earthquakes had been detected. Larger events were felt by residents during 13-14 September; the largest earthquake was a M 3.9, recorded at 0600 on 14 September. Overall, the events were becoming shallower (8-10 km) and hypocenters migrated slightly to the W. GPS and tiltmeter networks showed deformation totaling 1.5 cm centered over the clusters of epicenters.

A total of 10 seismic swarms have been detected at La Palma since 2017; one in 2017, one in 2018, five in 2020, and three in 2021. The earthquakes in the previous swarms were deeper, between 20 and 30 km, and were less intense than the current swarm.
Sources: Instituto Volcanológico de Canarias (INVOLCAN), Gobierno de Canarias, Instituto Geográfico Nacional (IGN)
Report for Pagan
The U.S. Geological Survey reported that emissions of ash and sulfur dioxide from Pagan were last detected on 6 September, though robust steam plumes occasionally continued to be visible at least through 14 September. The Aviation Color Code and the Volcano Alert Level were lowered to Yellow and Advisory, respectively, on 10 September.
Source: US Geological Survey
Report for Whakaari/White Island
On 14 September GeoNet reported that intermittent ash emissions at Whakaari/White Island continued to be visible during the previous week. Vigorous fumarolic plumes from the active vent area sometimes carried minor amounts of ash downwind at low altitudes and occasionally deposited ash on the island. Periods where ash was visible in the emissions did not correspond to explosive seismic or acoustic signals, suggesting that the ash was produced by weak wall fragments falling into the gas stream through the active vents and not from eruptive activity. Seismicity was characterized by low levels of volcanic tremor and occasional volcanic earthquakes. The Volcanic Alert Level remained at 2 and the Aviation Color Code remained at Yellow.
Source: GeoNet
Report for Aira
JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 6-10 September. Deformation data showed inflation beginning at around 0300 on 13 September. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Cerro Hudson
SERNAGEOMIN lowered the Alert Level for Cerro Hudson to Green (the lowest level on a four-color scale) on 7 September, based on decreased activity. Neither morphological changes nor thermal anomalies were visible in satellite images or webcam views during 16-31 August. Seismicity remained low and sulfur dioxide emissions were not recorded.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Report for Ebeko
According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 4 and 6-8 September produced ash plumes that rose as high as 2 km (6,600 ft) a.s.l. and drifted N, S, and E. Ash fell in Severo-Kurilsk on 6 and 8 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Great Sitkin
AVO reported that lava effusion continued at Great Sitkin during 7-14 September, though weather clouds often prevented webcam and satellite views. Seismicity remained elevated and was characterized by small earthquakes consistent with lava effusion. A radar image from 9 September indicated that the lava dome had grown to 1,100 m E to W and 860 m N to S, and was 25-30 m thick. Lava began to advance though a gap in the S rim of the summit crater. Elevated surface temperatures were visible in satellite data on 14 September. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Grimsvotn
Icelandic Meteorological Office (IMO) reported that the jökulhlaup from the eastern and western parts of Grímsvötn's caldera that began on 1 September had decreased during 8-10 September. IMO warned of continuing flood conditions in the downstream parts of the Skaftá river.
Source: Icelandic Meteorological Office (IMO)
Report for Ibu
PVMBG reported that during 7-12 September gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted N and W. The Alert Level remained at a 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karymsky
KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 3-10 September. Ash plumes rose 4 km (13,100 ft) a.s.l. and drifted 165 km E during 2-6 and 9 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Krysuvik-Trolladyngja
The fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, had paused for several days. The Institute of Earth Sciences reported that based on aerial photography acquired on 9 September, during the pause, the area of the flow field had grown to 4.6 square kilometers, and the total volume erupted was 143 million cubic meters. The crater floor was visible and was at least 70 m deep, with a deeper cavity or drainage sometimes visible.

Lava visibly returned on 11 September; RSAM values increased and low lava fountains emerged from a few areas on the flow field to the W of the main crater. Lava also returned to the main vent. Lava fountains from the main crater were visible for periods of 5-10 minutes on 13 September and lava advanced in multiple directions. Lava flowed N on 14 September. By 15 September lava quickly advanced S, flowing past the earthen barriers constructed at the S end of Geldingadalur valley, and turning E into the Nàtthagi valley. The Aviation Color Code remained at Orange due to the lack of ash and tephra emissions, though IMO warned of the potential for lapilli and scoria fallout within a 650 m radius of the active vent. Authorities also warned of gas emission hazards.
Sources: Icelandic Meteorological Office (IMO), Institute of Earth Sciences, Icelandic National Broadcasting Service (RUV), Oliver Lamb (University of North Carolina), Icelandic National Broadcasting Service (RUV), Benjamin Hennig (University of Iceland)
Report for Langila
Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 11-12 September ash plumes from Langila rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted W. A thermal anomaly at the summit was identified in satellite data.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 7-14 September. White-and-gray plumes rose as high as 700 m above the summit and drifted NWW, SW, and S. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Merapi
BPPTKG reported that both of Merapi’s two lava domes, situated just below the SW rim and in the summit crater, continued to grow during 3-9 September. The SW dome grew 5 m taller and had an estimated volume of 1.55 million cubic meters and the summit lava dome grew 1 m wider and had an estimated volume of 2.85 million cubic meters. One pyroclastic flow traveled 2 km down the SW flank and as many as 129 lava avalanches traveled a maximum of 2 km SW. According to the Darwin VAAC ash plumes rose 3 km (10,000 ft) a.s.l. and drifted E on 9 September, based on satellite and webcam views. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location.
Sources: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG), Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Nevados de Chillan
SERNAGEOMIN reported continuing explosive and effusive activity at Nevados de Chillán’s Nicanor Crater during 16-31 August, though weather conditions often prevented visual confirmation. Explosions generated ash plumes that rose as high as 1.1 km above the crater rim and were denser towards the end of August. Crater incandescence was sometimes visible at night, and though not intense, it brightened during explosive periods. The L5 and L6 lava flows continued to advance, though at a very low rate, averaging 1 m/h for L5. The L5 lava flow was 1,380 m long and L6 was 850 m long based on satellite images, measured from the rim of Nicanor Crater to the distal end of the flows. A decrease in thermal anomalies over the flows identified in satellite images suggested that the flows were cooling. The average temperature was 73 degrees Celsius with a maximum of 100 degrees for L5 and an average of 79 degrees Celsius with a maximum of 100 degrees for L6. Temperatures at the vents at Nicanor Crater averaged 115 degrees Celsius and were as high as 252 degrees during explosive phases. Sulfur dioxide emissions measured from local DOAS stations abruptly decreased and remained low. There was a total of five thermal anomalies, all with low radiance values. On 29 August pyroclastic flows traveled 560 m NE and collapses of L5’s middle and distal parts of the flow were observed. The Alert Level remained at Yellow, the second lowest level on a four-color scale. ONEMI stated that Alert Level Yellow (the middle level on a three-color scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 2 km away from the crater.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
Report for Pavlof
AVO reported that seismicity at Pavlof continued at low levels during 7-14 September and was interspersed with periods of more energetic tremor. Although weather clouds often obscured views, a series of four very minor ash emissions were visible in webcam images for a period of five hours on 10 September. The explosions produced minor and diffuse ash emissions that rose from a vent on the E flank and dissipated within minutes. A small explosion was recorded on 12 September and on 13 September, though cloud cover prevented visual confirmation of both events. The Volcano Alert Level and Aviation Color Code remained at Watch and Orange, respectively.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Semisopochnoi
AVO reported that eruptive activity at Semisopochnoi's North Cerberus crater continued during 7-14 September. Seismicity was elevated and characterized by periods of continuous tremor. Short-lived explosions lasting several minutes were detected daily in infrasound data. Small ash clouds from the explosions rose 3-4.6 km (10,000-15,000 ft) and dissipated within two hours. Sulfur dioxide emissions were detected in satellite images at altitudes less than 3 km (10,000 ft) a.s.l., sometimes extending downwind for hundreds of kilometers. During 7-9 September periods of lower-altitude ash emissions interspersed with voluminous steam plumes were observed in web camera images moving horizontally by the wind and rising no higher than 1.5 km (5,000 ft) a.s.l. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that a bright thermal anomaly over Sheveluch was identified in satellite images during 3-10 September. The Kamchatka Branch of Geophysical Services (KBGS; Russian Academy of Sciences) Kamchatka volcano station reported that tourists visiting the volcano on 8 September experienced ashfall; weather conditions prevented views of summit. The next day they saw a small pyroclastic flow and that night saw crater incandescence and small incandescent avalanches traveling SE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Institute of Volcanology and Geodynamics, Russian Academy of Natural Science
Report for Suwanosejima
JMA reported that four explosions at Suwanosejima's Ontake Crater produced eruption plumes that rose as high as 3.3 km above the crater rim during 3-10 September. Large volcanic bombs were ejected 500 m from the crater. Crater incandescence was visible nightly. The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Taal
PHIVOLCS reported that gas-and-steam plumes from Taal rose as high as 2.5 km above the lake during 8-14 September and drifted NE, SE, S, and SW. Sulfur dioxide emissions were 5,246-11,840 tonnes/day during 9-10 and 12-13 September. The Volcano Alert Level remained at a 2 (on a scale of 0-5). PHIVOLCS reminded the public that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ) and that boating on Taal Lake was prohibited.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)