All times are local unless otherwise stated.

Bezymianny | 16 December-22 December 2009 | New Activity / Unrest Cite this Report
Bezymianny Central Kamchatka (Russia)	KVERT reported that seismic activity from Bezymianny increased on 8 December. After a significant thermal anomaly was detected in satellite imagery on 17 December, the Level of Aviation Color Code was raised to Red. A few hours later a large explosive eruption produced ash plumes that were seen drifting as far as 350 km W and NW in satellite imagery. Ash plumes likely rose to altitudes greater than 10 km (32,800 ft) a.s.l.; clouds in the area prevented visual observations. Ashfall up to 3 mm thick was noted in Kozyrevsk, 45 km W, and other surrounding villages. The Level of Aviation Color Code was lowered to Orange after seismic activity significantly decreased. On 18 December another large thermal anomaly was seen over the volcano and on the SE flank. Gas-and-steam activity was also noted. During 19-20 December, a thermal anomaly continued to be detected in satellite imagery. KVERT lowered the Level of Aviation Color Code to Yellow on 21 December. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Cleveland | 16 December-22 December 2009 | New Activity / Unrest Cite this Report
Cleveland Chuginadak Island (USA)	On 18 December, AVO reported that a diffuse ash plume emitted from Cleveland on 12 December was retrospectively detected in satellite imagery. No other activity was noted. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Gaua | 16 December-22 December 2009 | New Activity / Unrest Cite this Report
Gaua Banks Islands (Vanuatu)	On 14 December, Vanuatu Geohazards Observatory reported that activity from Gaua during the previous month was characterized by continuous ash emissions accompanied by periodic steam emissions. Ashfall was reported in the W part of the island. Satellite imagery revealed that periods of significant gas emissions were more frequent than during November. Ash emissions during 14-18 December were thicker and darker, and possibly represented a new eruptive phase. Ash plumes continued to drift W and produce ashfall. The Vanuatu Volcanic Alert Level remained at 2 (on a scale of 0-4). Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)
Mayon | 16 December-22 December 2009 | New Activity / Unrest Cite this Report
Mayon Luzon (Philippines)	PHIVOLCS reported that during 14-19 December sulfur dioxide emissions from Mayon fluctuated between 750 and 2,034 tonnes per day. During 15-16 December, detached fragments from lava accumulating in the summit crater traveled as far as 4 km down the SE-flank Bonga-Buyuan gully, and lava flows traveled 700-800 m. Occasionally detached lava fragments produced small pyroclastic surges down the SW flank that generated light ashfall 13 km S and W in Camalig and Guinobatan, respectively. Steam plumes rose 200 m above the crater rim and drifted SW and WSW. During 17-20 December the seismic network detected 66 explosion-type signals; only 23 events were seen during periods of good visibility. These explosions produced dark gray to dark brown ash plumes that rose 500-2,000 m above the crater rim and drifted SW. Harmonic tremor was detected by the seismic network. Brownish-colored steam and intensified incandescence at night were noted. On 20 December lava flows had advanced 4.5 km from the crater. PHIVOLCS raised the Alert Level to 4 (on a scale of 0-5) and recommended that the Extended Danger Zone (EDZ) encompass an area 8 km S from the summit and 7 km N from the summit. During 20-22 December the rate and intensity of seismic signals dramatically increased. The sulfur dioxide emission rate also increased; 6,089-6,529 tonnes per day was measured. Booming and rumbling sounds, and intensified crater incandescence, were noted. Lava fountains rose 200 m above the crater and lava flowed as far as 5 km down the Bonga-Buyuan, Miisi, and Lidong gullies. According to news articles, more than 47,000 people from 30 villages were in evacuation centers across Albay province. About 3,000-6,000 residents had not evacuated. Sources: Inquirer.net, Philippine Institute of Volcanology and Seismology (PHIVOLCS), Associated Press
San Cristobal | 16 December-22 December 2009 | New Activity / Unrest Cite this Report
San Cristobal Sierra de los Marrabios	Based on METAR weather reports, the Washington VAAC reported that on 22 December a gas-and-steam plume that rose from San Cristóbal possibly contained ash. Source: Washington Volcanic Ash Advisory Center (VAAC)

Aira | 16 December-22 December 2009 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	Based on information from JMA, the Tokyo VAAC reported that during 16-17 and 20-22 December explosions from Sakura-jima produced plumes that rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted E, SE, and S. On 19 and 22 December, pilots reported that ash plumes rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Chaiten | 16 December-22 December 2009 | Continuing ActivityCite this Report
Chaiten Southern Chile	SERNAGEOMIN reported that during 1-15 December Chaitén's lava-dome complex produced steam, gas, and ash plumes that rose 2 km above the lava domes. On 7 December emissions originated from the N and S areas of the complex. Block-and-ash flows were noted the next day. The Alert Level remained at Red. Based on web camera views and SIGMET notices, the Buenos Aires VAAC reported that on 18 December an ash plume drifted SSE at altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Buenos Aires Volcanic Ash Advisory Center (VAAC)
Karymsky | 16 December-22 December 2009 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka (Russia)	KVERT reported that during 11-13 and 17 December a thermal anomaly over Karymsky was detected in satellite imagery. Seismic activity was above background levels on 12 and 13 December; data were not available during 11-21 December due to technical problems. The Level of Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea | 16 December-22 December 2009 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 16-22 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at Waikupanaha. Incandescence was seen almost daily coming from Pu'u 'O'o crater. The vent in Halema'uma'u crater continued to produce an off-white plume that drifted E and SW, dropping small amounts of ash downwind. Incandescence originated from a few holes in the deep floor of the vent cavity. Occasionally, lava ponded on the floor of the cavity. Spatter originated from a small spatter cone on the E side of the vent cavity floor. Spatter from the opening frequently fed small lava flows that traveled down the flank of the cone. The sulfur dioxide emission rate at the summit remained elevated; 600 tonnes per day were measured on 18 December. The 2003-2007 average rate was 140 tonnes per day. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Klyuchevskoy | 16 December-22 December 2009 | Continuing ActivityCite this Report
Klyuchevskoy Central Kamchatka (Russia)	KVERT reported that during 11-21 December seismic activity from Kliuchevskoi was above background levels. Satellite imagery revealed a large daily thermal anomaly at the volcano. The Level of Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Sangay | 16 December-22 December 2009 | Continuing ActivityCite this Report
Sangay Ecuador	Based on pilot observations, the Washington VAAC reported that on 18 and 21 December ash plumes from Sangay rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted W. Ash was not identified in satellite imagery, although weather clouds were present in the area. Thermal anomalies were occasionally detected in the satellite imagery. Source: Washington Volcanic Ash Advisory Center (VAAC)
Sheveluch | 16 December-22 December 2009 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	KVERT reported that during 11-21 December seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 5.5 km (18,000 ft) a.s.l. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome. The Level of Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Soufriere Hills | 16 December-22 December 2009 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	MVO reported that during 11-19 December activity from the Soufrière Hills lava dome continued at a high level. Night-time incandescence and observations with a high resolution thermal camera showed that activity was concentrated on the NW flank. Pyroclastic flows and semi-continuous rockfalls traveled down the NE, N, and NW flanks, channelling NE directly into Whites Ghaut and continuing into Whites Bottom Ghaut. Pyroclastic flows also traveled as far as 2 km NW down Tyers Ghaut multiple times a day, occasionally as far as 2 km W down Gages valley, and rarely E down Tar River valley. Fresh deposits from small pyroclastic flows moving S were seen at the head of the White River and Gingoes Ghaut. On 19 December heavy ashfall occurred in several areas in NW Montserrat. The Hazard Level remained at 4. Source: Montserrat Volcano Observatory (MVO)
Suwanosejima | 16 December-22 December 2009 | Continuing ActivityCite this Report
Suwanosejima Ryukyu Islands (Japan)	Based on information from JMA, the Tokyo VAAC reported eruptions from Suwanose-jima during 17-20 and 22 December. A plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. on 22 December. Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,386 individual reports over 1,186 weeks (average of 16 per week) on 331 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)