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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 29 August-4 September 2012
Name Location Eruption Start Date Report Status
Bezymianny Central Kamchatka (Russia) 2010 May 21 (?) New
Chachadake [Tiatia] Kunashir Island (Japan/Russia) New
Etorofu-Yakeyama [Grozny Group] Iturup (Etorofu) Island (Japan/Russia) New
Krakatau Indonesia New
Little Sitkin United States New
Soufriere Hills Montserrat New
Tungurahua Ecuador New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Batu Tara Komba Island (Indonesia) Continuing
Cleveland Chuginadak Island (USA) Continuing
Fuego Guatemala 2002 Jan 4 Continuing
Karymsky Eastern Kamchatka (Russia) 2020 Apr 1 Continuing
Kilauea Hawaiian Islands (USA) 2021 Sep 29 Continuing
Nevado del Ruiz Colombia 2014 Nov 18 Continuing
Popocatepetl Mexico 2005 Jan 9 Continuing
Santa Maria Guatemala 1922 Jun 22 Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 17,140 individual reports over 1,086 weeks (average of 16 per week) on 316 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 Vulcano
Cameroon Guntur Kuchinoerabujima Nyiragongo Sheveluch West Mata
Campi Flegrei del Mar di Sicilia Hachijojima Kurikomayama Okataina Shishaldin Westdahl
Cayambe Hakoneyama Kusatsu-Shiranesan Okmok Simbo Whakaari/White Island
Chachadake [Tiatia] Heard Kverkfjoll Ontakesan Sinabung Witori
Chaiten Hekla La Palma Oraefajokull Sinarka Wolf
Chiginagak Helgrindur Lamington Osorno Siple Yasur
Chikurachki Hierro Lamongan Pacaya Sirung Zaozan [Zaosan]
Chiles-Cerro Negro Hokkaido-Komagatake Langila Pagan Slamet Zavodovski
Chillan, Nevados de Home Reef Lanin Palena Volcanic Group Snaefellsjokull Zhupanovsky
Chirinkotan Hood Lascar Paluweh Soputan Zubair Group
Chirpoi Huaynaputina Lateiki Panarea Sorikmarapi
Ciremai 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 cover longer time periods and are more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

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

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

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

5. USGS Disclaimer Statement for this Website:

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

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

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

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

 Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

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

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

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

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

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

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

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

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

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

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

OFDA - Office of US Foreign Disaster Assistance

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

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

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

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)

Report for Bezymianny
KVERT reported that seismic activity at Bezymianny had increased in the middle of August. During 24-31 August levels were moderate; 17 events were recorded on 28 August and 71 events were recorded on 31 August. Observers noted weak-to-moderate fumarolic activity during 25-26 and 29 August; cloud cover prevented observations on the other days. A thermal anomaly was detected in satellite imagery on 25 August.

Based on seismic data analyses, an explosive eruption occurred from 0716 to 0745 on 2 September. Ash plumes rose to altitudes of 10-12 km (32,800-39,400 ft) a.s.l. and drifted more than 1,500 km ENE. A thermal anomaly observed in satellite imagery was very bright before the explosion. The Aviation Color Code was raised to Orange, then Red. Ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. and drifted NE later that day, then ash emissions ceased. Ash plumes continued to be detected in satellite imagery and drifted 450-600 km ENE and SE. The Aviation Color Code was lowered to Yellow. On 3 September seismic activity was low. A viscous lava flow effused on the lava-dome flank, and was accompanied by fumarolic activity and hot avalanches.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Chachadake [Tiatia]
SVERT reported that a weak thermal anomaly over Tiatia was detected in satellite images on 1 September. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Etorofu-Yakeyama [Grozny Group]
Based on visual observations and analyses of satellite imagery, SVERT reported that during 23 August-3 September fumarolic activity at Grozny Group increased. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Krakatau
CVGHM reported that during 1 June-1 September observations of Anak Krakatau were often prevented by fog; occasionally diffuse white plumes were observed rising from the crater in June. Seismicity increased significantly in August. On 2 September seismicity again increased, and at 1830 a Strombolian eruption ejected lava 200-300 m above the crater. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the volcano within 1 km of the crater.

Based on analyses of satellite imagery, the Darwin VAAC reported that on 3 September ash plumes rose to altitudes of 2.4-4.3 km (8,000-14,000 ft) a.s.l. and drifted 35-95 km N.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Little Sitkin
AVO reported that at approximately 1915 on 29 August a swarm of high-frequency earthquakes was detected at Little Sitkin. The anomalous seismic activity continued through the night, prompting AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. The rate of anomalous seismicity varied during 30-31 August; the two most active periods were during the morning of 30 August and at about 0400 on 31 August. The rate of earthquakes started to decline at around 0600 on 31 August, but remained elevated through 3 September. Little Sitkin is monitored by a four-station seismic network as well as satellite imagery.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Soufriere Hills
MVO reported that during 24-31 August activity at the Soufrière Hills lava dome was at a low level, although seismicity remained slightly elevated. At 1545 on 29 August a small pyroclastic flow traveled 1-1.5 km E down the Tar River Valley. The flow lasted 75 seconds, generated an ash cloud that rose 900-1,200 m and drifted W over Plymouth, and had an extensive fine-grained surge component. The Hazard Level remained at 2 (on a scale of 1-5).
Source: Montserrat Volcano Observatory (MVO)
Report for Tungurahua
IG reported that during 29 August-4 September visual observations of Tungurahua were often limited due to cloud cover. Moderate seismicity was detected during 29-30 August and a few earthquakes were felt by residents. On 30 August steam plumes with low ash content rose 500 m above the crater and drifted W. Ashfall was reported in Manzano (8 km SW) and Choglontus. Incandescent blocks rolled 300 m down the flanks, roaring was heard, and structures in nearby areas vibrated. During 31 Auguts-1 September steam plumes rose 300-500 m and drifted W. Glow emanated from the crater and incandescent blocks rolled down the flanks, up to 500 m on 31 August. Ashfall was reported in Manzano. An explosion produced a plume that rose 300 m on 3 September, and a steam plume drifted W on 4 September.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Aira
JMA reported that during 27-31 August five explosive eruptions from Sakura-jima's Showa Crater were detected and ejected tephra as far as 1.3 km from the crater. Gas measurements taken on 20 and 22 August showed elevated sulfur dioxide emissions compared to the previous week. Based on information from JMA, the Tokyo VAAC reported that explosions during 29-30 August and 1-4 September often produced plumes that rose to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. The plumes sometimes drifted N and NE. Pilots observed ash plumes during 1-2 September that rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l.
Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Japan Meteorological Agency (JMA)
Report for Batu Tara
Based on analyses of satellite imagery, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that during 30 August-4 September ash plumes from Batu Tara rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted 45-55 km W and NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Cleveland
AVO reported that satellite images of Cleveland from 17 August showed that the summit crater was tephra-covered, funnel-shaped, and contained no lava dome. Cloud cover prevented observations during 28 August-3 September. 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 Fuego
INSIVUMEH reported that during 29-30 August lava flows from Fuego traveled 250 m down the Taniluyá drainage (SW), generating block avalanches that produced gray plumes and reached vegetated areas.

Seismicity increased on 3 September. During 3-4 September constant Strombolian explosions generated ash plumes that rose 900 m above the crater and drifted 8 km S and SW. The eruption was heard in areas 10 km away and vibrated structures in Panimaché (8 km SW), Morelia (8 km SW), and Santa Sofia (12 km SE). Lava was ejected 100 m high and spilled over the crater rim. Lava flows traveled 3 km down the Taniluyá and the Ceniza (SSW) drainages, producing block avalanches that again reached vegetated areas. A third lava flow descended the Las Lajas drainage (SE). Pyroclastic flows traveled SE. Ash plumes drifted 10-12 km S and SW, and produced ashfall in Panimaché, Morelia, Santa Lucía, Cotzumalguapa, Tierra Linda, and Popoya.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Karymsky
KVERT reported weak-to-moderate seismic activity from Karymsky during 24-31 August. Volcanologists working on the flank observed explosive activity; ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. on 25 August. Satellite imagery showed a thermal anomaly on the volcano during 23-24, 26, and 28 August. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
During 28 August-4 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. On 28 August two major collapses of the inner wall significantly disrupted the lake's circulation.

Lava flows were periodically active on the pali and the coastal plain. At Pu'u 'O'o, a collapse of the crater floor just before 0400 on 30 August enlarged the newer pit crater at the S edge, making it appear slightly larger in the webcam views than the older, active, pit crater on the E edge. A new pit crater formed at the N edge of the floor after 1000, and by 1300 it was filled with lava. The N rim of the E pit crater fell into the lava lake there just before 1700. During 30-31 August incandescence emanated from the lava lake in the E pit crater but was absent from the S pit crater. A few scattered areas of flow activity on the coastal plain more than 2 km from the coast were visible on web cameras. On 1 September glow emanated from the E and S pit craters. Crusted lava filled the N pit crater and sagged, and a couple of small lava flows traveled from the edge onto the sagging crust. The N pit appeared to be a passive lava lake, without a direct source of magma underneath. A collapse in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o continued to glow but was less bright the next day.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Nevado del Ruiz
According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 30-31 August variations in volcanic tremor amplitude were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Seismic activity was low during 2-4 September. Cloud cover mostly prevented observations of the volcano; a white gas plume rose 200 m on 4 September and drifted W and SW. During 3-4 September field measurements and analysis of satellite imagery showed a significant amount of sulfur dioxide in the atmosphere. The Alert Level remained at II (Orange; "eruption likely within days or weeks").
Source: Servicio Geológico Colombiano (SGC)
Report for Popocatepetl
CENAPRED reported that during 29 August-4 September seismicity at Popocatépetl indicated continuing gas-and-steam emissions that may have contained ash; cloud cover often prevented visual observations of the volcano. Incandescence from the crater was observed at night. Gas plumes, that were sometimes bluish, rose up to 1 km above the crater and drifted NE, W, SW, and WSW. On 1 September the Alert Level was lowered to Yellow, Phase Two.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Santa Maria
INSIVUMEH reported that on 29 August fumarolic plumes from Santa María's Caliente dome rose 250-300 m and drifted SE. Small avalanches were active on the S part of the dome. Explosions on 3 September produced ash plumes that rose 200-800 m above Caliente dome and drifted W and SW. Four active lava flows generated block avalanches that traveled S down the Rio Nima I and Rio Nima II drainages. On 4 September hot lahars traveled S down the Rio Nima I and San Isidro drainages. The lahar in the San Isidro channel was 30 m wide and 2 m deep, emitted a sulfur odor, and carried blocks up to 1 m in diameter.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Sheveluch
KVERT reported that during 24-31 August a viscous lava flow was active on the NE flank of Shiveluch's lava dome and was accompanied by hot avalanches. Satellite imagery showed a thermal anomaly over the lava dome during 24-26 August; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)