All times are local unless otherwise stated.

Galeras (Colombia) | 14 December-20 December 2011 | New Activity / Unrest Cite this Report
Galeras Northern Andean Volcanic Arc	INGEOMINAS reported that activity continued at Galeras during 14-20 December, with steam rising from the main crater and two craters to the N and SW (Paisita and Chavas, respectively). The Alert Level remains at III (Yellow; "changes in the behavior of volcanic activity"). Source: Servicio Geológico Colombiano (SGC)
Gamalama (Indonesia) | 14 December-20 December 2011 | New Activity / Unrest Cite this Report
Gamalama Halmahera Volcanic Arc	Based on a SIGMET and information from the Ujung Pandang City MWO, the Darwin VAAC reported that on 14 December an ash plume from Gamalama rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 140 km S. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Ijen (Indonesia) | 14 December-20 December 2011 | New Activity / Unrest Cite this Report
Ijen Sunda Volcanic Arc	CVGHM reported that during 1 October-30 November white plumes from Ijen rose 50-150 m above the crater and lake water temperatures ranged from 26 to 31.6 degrees Celsius. During 1-14 December brownish-white plumes rose 50-200 m above the crater. The lake water temperature was 26.8 and 34.2 degrees Celsius on 8 and 14 December, respectively. Based on increased seismicity, visual observations, and lake water temperature increases, CVGHM raised the Alert Level from 1 to 2 (on a scale of 1-4). During 15-17 December seismicity significantly increased and sulfur dioxide gas emissions around the lake also increased. On 17 December the color of the lake water changed from light green to white. The Alert Level was raised to 3 the next day. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Tungurahua (Ecuador) | 14 December-20 December 2011 | New Activity / Unrest Cite this Report
Tungurahua Northern Andean Volcanic Arc	IG reported a decrease in activity from Tungurahua during 14-20 December. On 15 December steam plumes rose as high as 300 m above the crater and drifted W. Additional steam plumes observed on 17 December also drifted W. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Zubair Group (Yemen) | 14 December-20 December 2011 | New Activity / Unrest Cite this Report
Zubair Group Red Sea Rift Volcanic Province	According to local news, fishermen from the port city of Salif on the western Red Sea coast of Yemen reported an off shore eruption from the island of Jebel Zubair, about 60 km SW, with lava fountains rising 20-30 m above the summit on 19 December. On 19 December a SO2 cloud was detected in an OMI satellite image. MODIS imagery from 20 December shows a plume rising from a submarine eruption about 1.5 km SW of Haycock and N of Rugged (near the N end of the Az-Zubair island group), and about 12 km NE of Jebel Zubair island. A bathymetric sketch map made in 1973 indicates a water depth of about 100 m in that area. Sources: Yemen Observer, NASA Land Atmosphere Near Real-time Capability for EOS (LANCE), Toulouse Volcanic Ash Advisory Centre (VAAC), NASA Global Sulfur Dioxide Monitoring

Aira (Japan) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 14-20 December explosions from Sakura-jima produced plumes that rose to altitudes of 1.2-2.4 km (4,000-8,000 ft) a.s.l. and drifted SE and S. On 15 December satellite imagery showed ash emissions that later dissipated. A pilot reported that an ash plume rose to an altitude of 1.5 km (5,000 ft) and drifted 32 km S on 18 December. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Dukono (Indonesia) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that during 13-15 December ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l and drifted 55-75 km SW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Hierro (Spain) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Hierro Canary Volcanic Province	Instituto Geográfico Nacional (IGN) reported that during 14-20 December the submarine eruption continued S of El Hierro Island. During the beginning of the week, high-amplitude pulses were registered in the tremor signal every 5-10 minutes. On 15 December there were two long pulses around 7 minutes each, and after the second one the mean tremor amplitude values remained similar to those of previous weeks. Six seismic events were located during this period, both offshore to the N and inland, at depths between 3 and 22 km. GPS deformation data analyses showed stability in the horizontal components and deflation in the vertical component. Source: Instituto Geográfico Nacional (IGN)
Karymsky (Russia) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported that seismic activity continued at a moderate level at Karymsky during 9-16 December and indicated that possible ash plumes rose to an altitude of 4.1 km (13,500 ft) a.s.l. during 8-10 and 14 December. Satellite imagery showed a daily thermal anomaly and ash plumes that drifted 160 km SE during 12-13 December. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea (United States) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 14-20 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 21 September fissure on the SE flank of Pu'u 'O'o cone, from a skylight on the lava tube, and from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor. Pahoehoe flows that were 300-400 m wide, fed by lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili. The lava delta now extends 15-20 m into the ocean at a point 6.4 km W of the Chain of Craters Road. During 17-20 December the lava flow branched, with lobes advancing NE and W into the ocean. Infrequent plumes were observed from the ocean entry during 18-20 December. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Kizimen (Russia) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported increased seismic activity at Kizimen during 9-16 December. A series of strong seismic events were detected during 0547-0628 on 14 December. Explosions possibly produced ash plumes that rose to an altitude of 7.5 km (24,600 ft) a.s.l. Video observations showed hot avalanches from the lava flow and occasional large pyroclastic flows. During 0620-0810 a large pyroclastic flow with co-ignimbrite clouds was observed. Satellite images showed a thermal anomaly on the volcano all week and a gas-and-steam plume with ash from the pyroclastic flows that drifted 150 km during 13-14 December. A large lava flow on the NE and E flanks continued to effuse. The Aviation Color Code remained at Orange. The Tokyo VAAC reported that on 14 December an eruption detected in satellite imagery produced ash plumes that rose to altitudes of 6.1-7.6 km (20-25,000 ft) a.s.l. and drifted E. Subsequent notices stated that ash emissions which continued later that day dissipated on 15 December. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Popocatepetl (Mexico) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Popocatepetl Trans-Mexican Volcanic Belt	CENAPRED reported that during 14-20 December steam-and-gas emissions rose from Popocatépetl. Those emissions occasionally contained small amounts of ash on 14, 15, and 20 December. On 15 December an ash plume rose 1.2 km above the crater and drifted NE. During 18-19 December crater incandescence was observed early in the morning. An ash plume rose 900 m above the crater on 20 December. Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Puyehue-Cordon Caulle (Chile) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Puyehue-Cordon Caulle Southern Andean Volcanic Arc	Based on seismicity during 14-20 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 14-15 December rose 2.4-2.5 km above the crater and plumes were identified in satellite imagery drifting 30-50 km SE, S, and NE during 14-18. Satellite images showed ash plumes drifting 40-270 km SE, S, and NE during 14-18 December. The Alert Level remained at Red. Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Sheveluch (Russia) | 14 December-20 December 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that moderate seismic activity was detected at Shiveluch during 9-16 December. 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 10-11 and 13-15 December; clouds prevented observations on the other days of the week. The Aviation Color Code remained at Orange. Based on information from Yelizovo Airport (UHPP) and satellite images, the Tokyo VAAC reported that on 19 December an eruption produced a plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted E. On 20 December an ash plume drifted SE at an altitude of 4.3 km (14,000 ft) a.s.l. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)

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.

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)