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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, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail.

This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed narratives on various volcanoes are published as reports of the Bulletin of the Global Volcanism Network.

Smithsonian / USGS Weekly Volcanic Activity Report for the week of 28 August-3 September 2019
Name Location Eruption Start Date Report Status
Stromboli Aeolian Islands (Italy) 1934 Feb 2 New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Asosan Kyushu (Japan) Continuing
Dukono Halmahera (Indonesia) 1933 Aug 13 Continuing
Ebeko Paramushir Island (Russia) 2016 Oct 20 Continuing
Fuego Guatemala 2002 Jan 4 Continuing
Ibu Halmahera (Indonesia) 2008 Apr 5 Continuing
Karangetang Siau Island (Indonesia) 2018 Nov 25 Continuing
Karymsky Eastern Kamchatka (Russia) Continuing
Kerinci Indonesia 2018 Apr 21 Continuing
Klyuchevskoy Central Kamchatka (Russia) Continuing
Merapi Central Java (Indonesia) Continuing
Nevados de Chillan Chile 2016 Jan 8 Continuing
Pacaya Guatemala 2015 Jun 7 ± 1 days Continuing
Sabancaya Peru 2016 Nov 6 Continuing
Sangeang Api Indonesia Continuing
Santa Maria Guatemala 1922 Jun 22 Continuing
Semisopochnoi United States Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Shishaldin Fox Islands (USA) Continuing
Tangkuban Parahu Western Java (Indonesia) Continuing
Ubinas Peru Continuing
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 16,153 individual reports over 1,038 weeks (average of 16 per week) on 307 different volcanoes.

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


Download Smithsonian / USGS Weekly Volcanic Activity Report Network RSS Feed

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



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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 Stromboli
INGV reported that the paroxysmal eruption at Stromboli recorded at 1217 on 28 August produced an ash plume that rose 4 km above the summit. The eruption consisted of three explosions; the first two occurred at the Area C-S (South Central crater area), and the less intense third event occurred at Area N (north crater area) and ejected material onto the Sciara del Fuoco. Material from the collapse of the eruption plume contributed to the generation of a pyroclastic flow that traveled down the Sciara del Fuoco and several hundred meters out to sea. Morphological changes to Area N were evident after the paroxysm. The complex of small scoria cones, which had grown around the vents during the last few weeks, were destroyed. The NW crater rim of Area N had subsided, allowing lava flows to travel down the Sciara del Fuoco. During an overflight on 30 August volcanologists noted that Area N had collapsed and contained three vents generating Strombolian activity, and Area C-S had one large crater exhibiting Strombolian activity.

Strombolian activity resumed after the paroxysm on 28 August; lava flows from Area N reached the coastline by 1945. The next day lava from Area N flowed halfway down the Sciara del Fuoco at 2123 on 29 August and shed material from the front that rolled down to the coast. A new explosive sequence at Area C-S began at 2243 and produced tephra fall in Ginostra (1.5 km from the summit). A low-intensity explosion was recorded at 2329. A lava flow from Area C-S reached the sea during the early part of 30 August. Strombolian activity persisted at moderate levels during 31 August-3 September.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
Report for Aira
JMA reported that during 26 August-2 September very small eruptive events were detected at Minamidake crater (at Aira Caldera’s Sakurajima volcano), though none of them were explosive. Crater incandescence was visible in webcams at night during 1-2 September. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Asosan
JMA and the Tokyo VAAC reported that an eruptive event at Asosan was recorded at 1929 on 29 August; a plume rose 200 m above the crater rim and drifted N. During 30 August-3 September ash plumes rose as high as 250 m and drifted E, NE, N, and NW. The Alert Level remained at 2 (on a scale of 1-5).
Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Dukono
Based on satellite and wind model data, and information from PVMBG, the Darwin VAAC reported that during 28 August-3 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ebeko
KVERT reported that a thermal anomaly over Ebeko was identified in satellite images on 23 August. Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E, observed explosions during 27-28 August that sent ash plumes up to 3 km (10,000 ft) a.s.l. and drifted E. 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 Fuego
INSIVUMEH reported that there were multiple explosions per hour recorded at Fuego during 28 August-3 September, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-20 km W and SW. Explosions sometimes produced shock waves that rattled houses in nearby communities. Incandescent material was ejected 200-300 m high and caused avalanches of material that occasionally traveled long distances (reaching vegetated areas) down Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), El Jute (SE), Las Lajas (SE), and Honda ravines. Ashfall was reported in several areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), Sangre de Cristo (8 km WSW), Finca Palo Verde, San Pedro Yepocapa (8 km NW), and El Porvenir (8 km ENE).
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Ibu
PVMBG reported that at 1847 on 31 August an ash plume from Ibu rose at least 800 m above the summit and drifted N. Seismicity was characterized by an explosion signal and earthquakes indicating rock avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karangetang
PVMBG reported that during 26 August-1 September lava continued to effuse from Karangetang’s Main Crater (S) and Dua Crater (N), traveling as far as 1.5 km SW down the Nanitu and Pangi drainages, 1.4 km down a drainage W of Pangi, and 1.8 km down the Sense drainage. Sometimes dense white plumes rose to 200 m above the summit. The Alert Level remained at 2 (on a scale of 1-4).
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karymsky
KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 23-24 August along with ash plumes drifting 51 km SE. 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 Kerinci
The Darwin VAAC reported that on 2 September a possible minor ash plume from Kerinci rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted WSW, based on satellite images and weather models.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Klyuchevskoy
KVERT reported that a weak thermal anomaly over Klyuchevskoy was sometimes visible in satellite images and that gas-and-steam emissions continued, though ash was last emitted on 2 July. The Aviation Color Code was lowered to Yellow (the second highest lowest on a four-color scale) on 30 August.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Merapi
PVMBG reported that during 26 August-1 September the lava-dome volume at Merapi did not change and was an estimated 461,000 cubic meters, based on analyses of drone images on 8 August. Extruded lava fell into the upper parts of the SE flank, generating block-and-ash flows that traveled down the Gendol drainage; one flow traveled 2 km on 27 August. Diffuse white plumes rose as high as 80 m above the summit. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to stay outside of the 3-km exclusion zone.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Nevados de Chillan
ONEMI and SERNAGEOMIN issued special reports noting as many as three explosions per day at Nevados de Chillán’s Nicanor Crater during 28 August-1 September, with each explosion associated with long-period earthquakes. The webcam recorded gas emissions that turned gray with explosions rising 160-550 m above the crater during the daytime, and explosions ejecting incandescent material onto the NNE flank at night. Plumes drifted SE, NE, and NNW. The Alert Level remained at Orange, the second highest level on a four-color scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the communities of Pinto, Coihueco, and San Fabián, and stated that the public should stay at least 3 km away from the crater on the SW flank and 5 km away on the ENE flank.
Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI), Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Report for Pacaya
INSIVUMEH reported that during 28 August-3 September Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 30 m above the crater rim. Lava flows on the N and NNW flanks continued to advance, producing minor avalanches from the flow fronts.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Sabancaya
Instituto Geofísico del Perú (IGP) reported that an average of 26 low-to-medium intensity explosions per day occurred at Sabancaya during 26 August-1 September. Gas-and-ash plumes rose as high as 2 km above the summit and drifted SE, NW, and SW. There were 11 thermal anomalies identified in satellite data. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.
Source: Instituto Geofísico del Perú (IGP)
Report for Sangeang Api
The Darwin VAAC reported that during 28 August-3 September intermittent ash plumes from Sangeang Api were identified in satellite images rising to 3 km (10,000 ft) a.s.l. and drifting N, NW, W, and SW. The Alert Level remained at 2 (on a scale of 1-4).
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Santa Maria
INSIVUMEH reported that on most days during 28 August-3 September there were 2-4 explosions per hour detected at Santa María's Santiaguito lava-dome complex. Ash plumes rose 700-900 m above the complex and drifted SW and W. Avalanches of material descended the E, SE, and S flanks, sometimes producing ash plumes that rose along the path of the avalanche. Ash fell in Monte Claro (S) on 31 August.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semisopochnoi
AVO reported that low-level eruptive activity at Semisopochnoi possibly continued during 28 August-3 September. Seismic activity was relatively minor and characterized by intermittent low-frequency earthquakes. Minor tremor was detected until 30 August. Satellite images were obscured by clouds. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 22-25 August. Ash plumes on 25 August rose to 4.5-5 km (14,800-16,400 ft) a.s.l. and drifted more than 500 km NW. At 1510 on 29 August explosions produced ash plumes that rose to 10 km (32,800 ft) a.s.l. The leading part of the plume drifted W and then curved counterclockwise to the S, then E, and finally drifted 550 km N. Explosions at 1957 on 30 August produced ash plumes that rose to 7-7.5 km (23,000-24,600 ft) a.s.l. and drifted 50 km SSE. Ash plumes drifted SE at an altitude of 5.5 km (18,000 ft) a.s.l. on 3 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 Shishaldin
Low-level lava fountaining and minor explosive activity within Shishaldin’s summit crater was last observed on 17 August and likely continued during 28 August-2 September; continuous tremor was recorded by the seismic network and moderately-elevated surface temperatures were visible in satellite images. 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 Tangkuban Parahu
PVMBG reported that during 26 August-1 September emissions at Tangkubanparahu's Ratu Crater were characterized by puffs of dense black ash plumes rising as high as 20 m above the vent and white vapor plumes containing minor amounts of ash rising as high as 200 m. A larger event recorded at 0930 on 31 August generated a dense black tephra plume that rose 300 m and a white steam plume that rose 600 m. Ashfall was localized around Ratu Crater. The seismic network recorded continuous tremor. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 1.5 km away from the active crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ubinas
IGP reported that during 27 August-2 September gas-and-water-vapor plumes from Ubinas rose to heights less than 1 km above the summit, and three thermal anomalies were recorded by the MIROVA system. The number of seismic events was 2,828 (all under M 2.3), with volcano-tectonic (VT) signals being the most numerous. There was a slight increase in the number of long-period, hybrid, and VT events compared to the previous week. Beginning at 2145 on 1 September a period of continuous ash emissions was recorded by the webcam. An explosion at 1358 on 3 September generated an ash plume that rose 1.3 km above the summit and drifted more than 10 km S and SE. Prior to this event, the last explosion as recorded on 22 July. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 15-km radius.
Source: Instituto Geofísico del Perú (IGP)