All times are local unless otherwise stated.

Bezymianny (Russia) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Bezymianny Eastern Kamchatka Volcanic Arc	KVERT reported that during 22-29 April a bright thermal anomaly on Bezymianny was detected in satellite imagery. A gas-and-steam plume that drifted 27 km NW was also detected on 22 April. According to ground-based observations, gas-and-steam activity was noted during 22 and 24-25 April. The Aviation Color Code was lowered to Yellow. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Gamkonora (Indonesia) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Gamkonora Halmahera Volcanic Arc	CVGHM reported that during January-April diffuse white plumes from Gamkonora rose 25-100 m above the crater rim. Seismicity increased during 29 April-3 May. On 1 May, white plumes rose 150 m above the crater rim. The next day, white plumes rose 300 m above the crater rim and incandescence from the crater was observed. Residents near the volcano's base noted a sulfur smell. The Alert level was raised to 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Kizimen (Russia) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Kizimen Eastern Kamchatka Volcanic Arc	Based on analyses of satellite imagery, KVERT reported that during 22-29 April a large bright thermal anomaly was detected over Kizimen daily and ash plumes drifted 135 km in multiple directions. Ground-based observations indicated that gas-and-steam plumes with a small amount of ash rose to an altitude of 3.5 km (11,500 ft) a.s.l. and drifted W during 20-21 April. The Aviation Color Code remained at Orange. On 3 May seismic data indicated a possible series of ash plumes and avalanches. An ash plume may have risen to an altitude of 10 km (33,000 ft) a.s.l. The Aviation Color Code was raised to Red. On 4 May seismicity decreased but remained high. Satellite imagery showed ash plumes at altitudes of 4-6 km (13,100-19,700 ft) a.s.l. The Aviation Color Code was lowered to Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Planchon-Peteroa (Chile) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Planchon-Peteroa Andean Southern Volcanic Arc	SERNAGEOMIN reported that during 1-15 April a camera installed in Romeral, approximately 61 km NW of Planchón-Peteroa, recorded predominantly white vapor plumes that rose at most 600 m. During 16-19, 21 and 25-29 April episodes of ash-plume production changed from discreet plumes to more continuous emissions. Ash plumes during 17-19 and 29 April rose 1.2 km and contained ash- to lapilli-sized particles. During overflights on 26, 27, and 29 April, a geologist noted that the crater geometry and fumarolic activity had changed very little during the previous few months and that ash emissions drifted mainly SW. SERNAGEOMIN stated that because ash-and-gas emissions were becoming almost continuous, the Alert Level was raised to Level 3, Yellow on 29 April. Based on analyses of satellite imagery, SIGMET notices, and ODVAS web camera observations, the Buenos Aires VAAC reported that during 2-3 May gas-and-ash plumes rose to altitudes of 4.6-5.5 km (15,000-18,000 ft) a.s.l. and drifted NE and E. Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC), Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Puyehue-Cordon Caulle (Chile) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Puyehue-Cordon Caulle Andean Southern Volcanic Arc	ODVAS-SERNAGEOMIN reported that on 26 April an overflight was conducted in response to recent increased seismicity and nearby residents noting fumarolic activity in the vicinity of Puyehue-Cordón Caulle. Scientists did not observe anything unusual that would indicate increased activity at Puyehue or Cordón Caulle, just typical fumarolic activity. On 27 April a seismic swarm was detected at depths of 4-6 km; a majority of the events were hybrid earthquakes and the largest was M 3.9. Seismicity decreased but was continuing through 29 April. The Alert Level was raised to 3, Yellow. Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Ruapehu (New Zealand) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Ruapehu Taupo Volcanic Zone	On 2 May, GeoNet reported that the temperature of Ruapehu's summit Crater Lake continued to slowly cool and was about 30 degrees Celsius, down from a peak of 41 degrees in March. The lake level remained below the overflow level and no earthquakes had been located within 10 km of the Crater Lake for two weeks. The Aviation Colour Code was lowered to Green and the Volcanic Alert Level remained at 1 (signs of volcano unrest). Source: GeoNet
Tungurahua (Ecuador) | 27 April-3 May 2011 | New Activity / Unrest Cite this Report
Tungurahua Andean Northern Volcanic Arc	IG reported that, although visual observations of Tungurahua were occasionally limited due to cloud cover during 26 April-3 May, ash plumes were noted daily and rose to altitudes of 7-12 km (23,000-39,400 ft) a.s.l. The plumes drifted in multiple directions. Ashfall was reported daily in areas within 8 km NNE, N, NW, W, and SW. On 27 and 29 April and during 1-3 May ashfall was reported in areas farther away including the Tungurahua Observatory (OVT) in Guadalupe (11 km N), Ambato (31 km NW), Mocha (25 km W), and 40 km WSW. Blocks ejected from the crater rolled down the flanks on most days and explosions periodically caused doors and windows to vibrate. On 29 April tremor intensified and Strombolian activity increased. According to news articles, an IG scientist noted that boulders the size of a truck were ejected from the crater, causing impact craters 10 m wide where they fell on the flanks. About 300 people evacuated. Sources: Batangas Today, Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Aira (Japan) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 27-30 April and 2-3 May explosions from Sakura-jima produced plumes that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted N, NE, E, SE, and S. On 29 April and 2 May, pilots observed ash plumes that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted S and SE. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Batu Tara (Indonesia) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Batu Tara Sunda Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that during 28 April-3 May ash plumes from Batu Tara rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 10-130 km N, NW, W, and SW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Dukono (Indonesia) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that during 28 April-2 May ash plumes from Dukono rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted 55-150 km NW, W, and SW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Fuego (Guatemala) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Fuego Central America Volcanic Arc	INSIVUMEH reported that during 28-29 April explosions from Fuego produced ash plumes that rose 300-600 m above the crater and drifted SW and S. The explosions sometimes produced shock waves. Lava flows traveled 200 m S and block avalanches descended the Ceniza and Santa Teresa drainages. Explosions during 1-2 May produced ash plumes that rose 200 m above the crater. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Karymsky (Russia) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported moderate seismic activity at Karymsky during 22-29 April and a thermal anomaly that was detected daily in satellite imagery. Seismic data indicated that possible ash plumes rose to an altitude of 3.4 km (11,200 ft) a.s.l. Visual observations showed that moderate explosive activity continued. During 22-23 April gas-and-steam plumes detected in satellite imagery drifted 38 km S. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea (United States) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 27 April-3 May, HVO reported that the level of Kilauea's summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava from one or two vent sources continued to fill in a new lava lake in the center of the crater floor. Lava overflowed the edges of the lake, constructing a perched lava lake. During 30 April-1 May the overflows filled the entire crater floor before receding back within the boundaries of the perched lava lake. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Santa Maria (Guatemala) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	INSIVUMEH reported that during 28-29 April explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 600-800 m above the crater and drifted S, SW, and W. Block avalanches descended the flanks of Caliente dome. At night pyroclastic flows traveled down the Rio Nima I and Rio Nima II drainages. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch (Russia) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that during 22-29 April seismic data at Shiveluch indicated that possible ash plumes rose to an altitude of 6.7 km (22,000 ft) a.s.l. Satellite imagery showed a thermal anomaly daily on the lava dome. According to ground-based observations during 22 and 25-27 April ash plumes rose to an altitude of 7.5 km (24,600 ft) a.s.l. and drifted N and SE. Satellite imagery showed ash plumes drifting 153 km N on 22 April and as far as 400 km SE during 23-24 and 27 April. KVERT noted that the Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 1 May an eruption produced a plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)
Suwanosejima (Japan) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Suwanosejima Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 3 May. Details of a possible resulting plume were not reported. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Tengger Caldera (Indonesia) | 27 April-3 May 2011 | Continuing ActivityCite this Report
Tengger Caldera Sunda Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that on 27 April an ash plume from Tengger Caldera's Bromo cone rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted about 75 km WSW. On 2 May an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted about 75 km N. Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,322 individual reports over 1,229 weeks (average of 17 per week) on 336 different volcanoes.

Use the dropdowns to choose the year and week for archived Weekly Reports.

 News Feeds and Google Placemarks

 Criteria & Disclaimers

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.

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.

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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)