All times are local unless otherwise stated.

Galeras (Colombia) | 7 December-13 December 2011 | New Activity / Unrest Cite this Report
Galeras Northern Andean Volcanic Arc	INGEOMINAS reported that activity continued at Galeras during 7-13 December, with steam rising from the main crater and two craters to the N and SW (Paisita and Chavas, respectively). On 9 and 11 December earthquakes of M 2.3 and 2.5, felt by local residents, occurred near the crater at a depth of 1.5 km. The Alert Level remains at III (Yellow; "changes in the behavior of volcanic activity"). olcanic activity"). Source: Servicio Geológico Colombiano (SGC)
Gamalama (Indonesia) | 7 December-13 December 2011 | New Activity / Unrest Cite this Report
Gamalama Halmahera Volcanic Arc	Based on information from CVGHM, the Darwin VAAC reported that during 7-10 December ash plumes from Gamalama rose to altitudes of 2.1-6.1 km (7,000-20,000 ft) a.s.l. and drifted E and SE. The Alert Level for Gamalama remains at 3 (on a scale from 1-4). Source: Washington Volcanic Ash Advisory Center (VAAC)
Sorikmarapi (Indonesia) | 7 December-13 December 2011 | New Activity / Unrest Cite this Report
Sorikmarapi Sunda Volcanic Arc	CVGHM reported increased seismicity from Sorik Marapi during 1-12 December and white plumes rose 40-50 m above the summit. CVGHM raised the Alert Level on 12 December from 1 to 2 (on a scale of 1-4) based on seismic data. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Sundoro (Indonesia) | 7 December-13 December 2011 | New Activity / Unrest Cite this Report
Sundoro Sunda Volcanic Arc	CVGHM reported increased seismic activity at Sundoro during October -4 December. On 26 November and 2 December smoke was reported from many fumaroles around the summit crater. Based on visual and seismic data, CVGHM raised the Alert Level from 1 to 2 (on a scale of 1-4) on 5 December. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Tungurahua (Ecuador) | 7 December-13 December 2011 | New Activity / Unrest Cite this Report
Tungurahua Northern Andean Volcanic Arc	IG reported that during 7-8 December activity continued at Tungurahua and roaring noises and sounds resembling "cannon shots" were heard. Ash plumes rose to altitudes of 1.5-4.0 km (4,920-16,400 ft) drifting W and NE on 7 December, and W and SW on 8 December. Ashfall was reported in communities to the W, NE, and SW. On 8 December ashfall was reported in Choglontús (SW), Chacauco, Manzano (8 km SW), Bilbao (8 km W), and Pillate (8 km W). Crater incandescence was observed on 10 December, but activity decreased during 10-11 December. Based on pilot and satellite observations, the Washington VAAC reported that during 7-8 December ash plumes from Tungurahua rose to altitudes of 7.0-7.9 km (23,000 -26,000 ft) a.s.l. and drifted 18.5-24.0 km S and SW. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC)

Aira (Japan) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 7-13 December explosions from Sakura-jima produced plumes that rose to altitudes of 1.0-2.7 km (3,000-9,000 ft) a.s.l. and drifted E, SE, S, and NE. Satellite imagery and a pilot report showed ash plumes that rose to an altitude of 2.4 km (8,000 ft) a.s.l and drifted 46 km SW on 9 December and 37 km S on 13 December. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Dukono (Indonesia) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that on 13 December an ash plume from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 74 km SW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Fuego (Guatemala) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Fuego Central America Volcanic Arc	INSIVUMEH reported that on 9 and 13 December explosions from Fuego produced rumbling sounds and ash plumes that rose 300-600 m above the crater and drifted W, SW, and S. Block avalanches descended the SW flank toward the Ceniza drainage. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Hierro (Spain) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Hierro Canary Volcanic Province	Instituto Geográfico Nacional (IGN) reported that during 7-13 December the submarine eruption continued S of El Hierro Island, with steaming lava fragments sporadically observed floating on the sea. During this period, the mean tremor amplitude oscillated between decreasing and increasing trends during the first days of the week, and since 10 December high-amplitude pulses occurred every 5-10 minutes. Only seven seismic events were located during this period, most of them offshore to the N of the island at depths of 17-23 km and with a maximum magnitude of 2.0. GPS data analyses showed stability in the horizontal components and trends to deflation in the vertical component. Source: Instituto Geográfico Nacional (IGN)
Karymsky (Russia) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported that seismic activity continued at a moderate level at Karymsky during 2-9 December and indicated that possible ash plumes rose to an altitude of 3.6 km (11,800 ft) a.s.l. Satellite imagery showed a daily thermal anomaly and ash plumes that drifted 90 km E on 3, 7, and 8 December. The Aviation Color Code remained at Orange. Based on information from KVERT, the Tokyo VAAC reported that on 13 December an ash plume rose to an altitude of 3.0 km (10,000 ft) a.s.l. and drifted E. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Kilauea (United States) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 7-13 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible along the E and W edges of the Pu'u 'O'o crater floor, along the 21 September fissure on the SE flank of Pu'u 'O'o cone, and from a skylight on the lava tube. Lava continues to erupt into the perched pond formed on 6 December. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o based on intermittent views from satellite. Analysis of 10-12 December satellite images suggested that lava had reached the coast and was flowing into the ocean. During 11-12 December incandescence was observed from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor; short lava flows issued from the E edge of the crater floor on 12 December. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Kizimen (Russia) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported an increase in seismic activity at Kizimen during 2-9 December and a daily thermal anomaly that was detected in satellite images. A large lava flow on the NE and E flanks continued to effuse. The video camera was down due to technical reasons during the week. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Popocatepetl (Mexico) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Popocatepetl Trans-Mexican Volcanic Belt	CENAPRED reported that during 7-13 December steam-and-gas emissions rose from Popocatépetl and occasionally contained small amounts of ash. On 7 December ashfall was reported in San Pedro (13.5 km NW). Crater incandescence was observed during 9-11 December and on 9 December incandescence ballistic fragments were observed on the upper slopes of the cone. Based on reports from CENEPRED and the Mexico City MWO, the Washington VAAC reported an ash plume that drifted 12.9 km W on 7 December. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
Puyehue-Cordon Caulle (Chile) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Puyehue-Cordon Caulle Southern Andean Volcanic Arc	Based on seismicity during 7-13 December, 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. Plumes observed with the web camera during 8-9 December rose 3.0-3.5 km above the crater and plumes were identified in satellite imagery drifting 90 km SE on 8 December and 250 km ENE on 9 December. Cloud cover prevented web camera and satellite observations during 10-13 December, but ashfall was reported to the E during 10-11 December. The Alert Level remained at Red. Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Santa Maria (Guatemala) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	INSIVUMEH reported that on 9 December plumes from Santa María's Santiaguito lava-dome complex rose 300 m above the crater and drifted SW and explosions generated rumbling noises. On 13 December block avalanche activity increased on the S flank and created pyroclastic flows that were deposited into the San Isidro drainage. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch (Russia) | 7 December-13 December 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that moderate seismic activity was detected at Shiveluch during 2-9 December, and satellite imagery showed a daily thermal anomaly over the lava dome. Ground-based observers noted that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Moderate fumarolic activity at the lava dome was observed during 3-6 December; clouds prevented observations on the other days of the week. 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 20,652 individual reports over 1,244 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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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)