All times are local unless otherwise stated.

Cleveland (United States) | 14 September-20 September 2011 | New Activity / Unrest Cite this Report
Cleveland Aleutian Ridge Volcanic Arc	AVO reported that during 13-17 September no lava-dome activity in Cleveland's summit crater was observed in partly cloudy satellite images. During 17-18 September a thermal anomaly was detected in satellite images. A report on 20 September noted that recent observations revealed the lava dome had grown to about 165 m in diameter, remained contained within the crater, and was 20 m below the E crater rim. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Etna (Italy) | 14 September-20 September 2011 | New Activity / Unrest Cite this Report
Etna Sicily Volcanic Province	Sezione di Catania - Osservatorio Etneo reported that the fourteenth eruption from Etna's New SE Crater in 2011 occurred during poor weather conditions on 19 September. Lava fountains rose from multiple vents within the crater and lava flows descended the W slope of the Valle del Bove. An ash plume drifted NE; ash and lapilli fell in an area to the N of Giarre (16 km E). The main phase of the event lasted from about 1020 until just after 1300. During the evening the lava flows were active and weak spattering continued from a vent at the SE base of the SE Crater cone. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Hierro (Spain) | 14 September-20 September 2011 | New Activity / Unrest Cite this Report
Hierro Canary Volcanic Province	Instituto Geográfico Nacional (IGN) reported more than 900 seismic events at Hierro island during 8-19 September, three of them felt by residents. The total number of located earthquakes had reached more than 7,200 since anomalous activity began on 16 July, with patterns alternating between relatively calm and high-energy periods. The GPS local network showed similar deformation rates compared to previous weeks. Source: Instituto Geográfico Nacional (IGN)

Aira (Japan) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 14-20 September explosions from Sakura-jima produced plumes that rose to altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. and drifted S, SW, W, and NW. On 14 September a pilot observed an ash plume that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted W. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Batu Tara (Indonesia) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Batu Tara Sunda Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that during 13-20 September ash plumes from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 25-75 km W, WNW, and NW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Bezymianny (Russia) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Bezymianny Eastern Kamchatka Volcanic Arc	KVERT reported that during 9-15 September seismic activity at Bezymianny was low. An observer in the area on 6 September noted that lava continued to effuse on the SSE flank. The Aviation Color Code remained at Yellow. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Fuego (Guatemala) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Fuego Central America Volcanic Arc	INSIVUMEH reported that during 13-14 September explosions from Fuego produced ash plumes that rose 800 m above the crater. The explosions occasionally produced shock waves detected 7 km away. Incandescence at night emanated from the crater and from avalanches on the flanks. During 15-16 September cloud cover prevented observations of the crater but explosions were heard. Block avalanches descended the flanks and an ash plume drifted 7 km W. During 19-20 September explosions produced ash plumes that rose 500 m above the crater and drifted W. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Karymsky (Russia) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported that seismic activity continued at a moderate level at Karymsky during 9-15 September, and indicated that possible ash plumes rose to an altitude of 4.6 km (15,100 ft) a.s.l. during 13-14 September. An observer in the area noted that ash explosions produced ash plumes all week that did not rise higher than 3.5 km (11,500 ft) a.s.l. A thermal anomaly was detected daily in satellite imagery and ash plumes drifted 80 km E and SE during 11-12 and 14 September. The Aviation Color Code remained at Orange. Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 20 September an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NE. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Kilauea (United States) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 14-20 September, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated and circulated. Daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At the E rift zone, lava in the E lava lake overflowed the E rim of Pu'u 'O'o crater on 13 September and advanced a few hundred meters. Lava erupted within the W lava lake and the next day overflowed the W edge of the crater through two broad gaps in Pu'u 'O'o cone, spreading up to several hundred meters downslope and mantling the W flank of Pu'u 'O'o. The flows had stopped by the evening of 15 September. During 15-16 September the level of the lava lakes had dropped 10-15 m. During 17-18 September the W lake was inactive and the E lake weakly bubbled and slowly circulated. Activity within the W lake increased abruptly on 19 September and, during 19-20 September, lava flowed across the W part of the crater floor. On 20 September lava refilled two perched lava ponds on the W edge of the crater, overflowed the southern-most pond, and produced a channelized lava flow that advanced 800 m down Pu'u 'O'o's W flank. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Kizimen (Russia) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported that during 9-15 September volcanic tremor magnitude at Kizimen continued to increase; 1,200-1,500 earthquakes were recorded daily. A thermal anomaly on the volcano was detected in satellite images. Lava on the E flank continued to flow and video images showed strong fumarolic activity. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Puyehue-Cordon Caulle (Chile) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Puyehue-Cordon Caulle Southern Andean Volcanic Arc	Based on seismicity during 14-16 and 18-20 September, OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Although cloudy weather mostly prevented observations of the vent, a plume was observed in satellite imagery drifting 60 km E on 14 September, and the next day, a plume observed by an area camera rose 4 km above the crater and drifted SE. Plumes observed in satellite imagery drifted 40-70 km N and NW during 18-20 September. Plumes observed during 19-20 September by an area camera rose 3-4 km above the crater. According to a news article, on 17 September the first commercial plane landed at the airport in Bariloche, about 60 km SE, since the airport had closed on 4 June. Private planes had been occasionally using the airport since mid-July. The Alert Level remained at Red. Sources: Agence France-Presse (AFP), Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Santa Maria (Guatemala) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	INSIVUMEH reported that during 13-16 September lava flows were active on the SW and SE flanks of Santa María's Santiaguito lava dome complex. Avalanches from the lava-flow fronts also descended the flanks. Ash plumes drifted ENE. An explosion accompanied by rumbling generated an ash plume that rose 700 m above the crater and drifted SW. On 15 September a small lahar traveled down the Rio Nima II drainage. Incandescence emanated at night during 15-16 September from the lava flows and during 15-16 and 19-20 September from the crater. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch (Russia) | 14 September-20 September 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that seismic activity at Shiveluch was moderate during 9-15 September, and indicated that possible ash plumes rose to altitudes of 6.5 km (14,100 ft) and 10.3 km (33,800 ft) a.s.l. on 9 and 11 September, respectively. Ground-based observers noted ash plumes that rose to an altitude of 4.7 km (15,400 ft) a.s.l. on 9 September and fumarolic activity on 9 and 14 September. A thermal anomaly on the volcano was also observed in satellite imagery on 9 and 13 September. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,627 individual reports over 1,243 weeks (average of 17 per week) on 338 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)