All times are local unless otherwise stated.

Karangetang (Indonesia) | 30 March-5 April 2011 | New Activity / Unrest Cite this Report
Karangetang Sangihe Volcanic Arc	CVGHM reported that during 30-31 March incandescence emanated from Karangetang's main crater as well as bluish and white gas plumes. Lava flows originating from the main crater traveled 2 km down the flanks. Incandescent avalanches from the main crater and from the lava-flow fronts traveled up to 1.8 km down the flanks. On 31 March a thunderous sound was accompanied by a gray plume that rose 200 m above the crater. The Alert Level remained at 3 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Kilauea (United States) | 30 March-5 April 2011 | New Activity / Unrest Cite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	HVO reported that lava in the deep pit within Kilauea's Halema'uma'u crater was visible on 5 April and rose, fell, and circulated within the pit during 6-12 April. At Pu'u 'O'o crater, the level of the lava lake fluctuated, and was fed from a source in the central portion of the lake. During 5-8 April a gas plume from the vent deposited very small amounts of ash nearby, derived from rockfalls and occasional lake spatter. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Ruapehu (New Zealand) | 30 March-5 April 2011 | New Activity / Unrest Cite this Report
Ruapehu Taupo Volcanic Zone	On 5 April, GeoNet reported that the temperature of Ruapehu's summit Crater Lake had been high for a sustained period and was currently between 38 and 39 degrees Celsius. The highest temperature since unrest began in October 2010 was 41 degrees Celsius, measured on 1 March. The report also noted that during the previous few weeks there was an increase in carbon dioxide gas emissions, increased seismicity, and changes in Crater Lake water chemistry. The unrest prompted GeoNet to raise the Aviation Colour Code although the Volcanic Alert Level remained at 1 (some signs of volcano unrest). Source: GeoNet

Aira (Japan) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 1 and 3-5 April explosions from Sakura-jima produced plumes that rose to altitudes of 1.5-4 km (5,000-13,000 ft) a.s.l. and occasionally drifted E. A video of activity from 4 April showed incandescence emanating from the crater and a few explosions that ejected incandescent material onto the flanks. On 5 April, a pilot observed an ash plume that rose to an altitude of 2.7 km (9,000 ft) a.s.l. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Volcano Sakura-jima
Cleveland (United States) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Cleveland Aleutian Ridge Volcanic Arc	On 31 March, AVO lowered the Volcano Alert Level and the Aviation Color Code for Cleveland to Unassigned noting that no eruptive activity had been confirmed during the previous few months. Neither significant thermal anomalies nor ash deposits on snow were observed in recent satellite imagery. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Dukono (Indonesia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that on 4 April an ash plume from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 185 km E. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Etna (Italy) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Etna Sicily Volcanic Province	Based on a NOTAM, the Toulouse VAAC reported that on 3 April ash from Etna rose to an altitude between 2.4-3.4 km (8,000-11,000 ft) a.s.l. Ash was not identified in satellite imagery. Source: Toulouse Volcanic Ash Advisory Centre (VAAC)
Fuego (Guatemala) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Fuego Central America Volcanic Arc	INSIVUMEH reported that during 30-31 March and 4-5 April explosions from Fuego produced ash plumes that rose 200-700 m above the crater and drifted W, SW, and S. Lava flows traveled almost 200 m SW down the Ceniza drainage and produced block avalanches from lava-flow fronts. Crater incandescence was observed at night. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Galeras (Colombia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Galeras Northern Andean Volcanic Arc	INGEOMINAS reported that on 31 March and 1 April emissions from Galeras were characterized by gas-and-steam plumes with low ash content. On 1 April a M 2.3 earthquake occurred 3 km E of the crater at a depth of 6 km and was felt by nearby residents. During an overflight on 2 April scientists noted a sulfur gas odor and observed that gas emissions rose from multiple areas of the active cone. During 30 March-5 April, sulfur dioxide gas values were between 50 and 2,000 tons per day, the latter value was considered high for Galeras. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity"). Source: Servicio Geológico Colombiano (SGC)
Karymsky (Russia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported moderate seismic activity at Karymsky during 25 March-1 April. Seismic data indicated that possible ash plumes rose to an altitude of 5 km (16,400 ft) a.s.l. A thermal anomaly was detected daily in satellite imagery. Ash and gas-and-steam plumes drifted 55 km in multiple directions during 25, 27, and 29-30 March. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kirishimayama (Japan) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Kirishimayama Ryukyu Volcanic Arc	Based on notifications from JMA and pilot observations, the Tokyo VAAC reported that during 3-4 April ash plumes from Kirishima's Shinmoe-dake (Shinmoe peak) rose to altitudes of 4.6-6.1 km (15,000-20,000 ft) a.s.l. and drifted E. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Kizimen (Russia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported that during 25 March-1 April seismicity from Kizimen was high, with many shallow volcanic earthquakes and volcanic tremor continuing to be detected. Satellite images showed a large bright thermal anomaly daily on the volcano. Ash and gas-and-steam plumes drifted multiple directions as far as 464 km. The Aviation Color Code remained at Orange. Based on analyses of satellite imagery, the Tokyo VAAC reported that a possible eruption on 1 April produced a plume that rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted E. Subsequent images that day and during 2-3 April showed continuing ash emissions. Another possible eruption on 6 April produced a plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Klyuchevskoy (Russia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Klyuchevskoy Eastern Kamchatka Volcanic Arc	Based on analyses of satellite imagery, the Tokyo VAAC reported that a possible eruption from Kliuchevskoi on 30 March produced a plume that rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted E. Subsequent images that day showed continuing ash emissions that later dissipated. The Aviation Color Code remained at Green. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Santa Maria (Guatemala) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	INSIVUMEH reported that on 28 March explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 300-800 m above Caliente dome and drifted NNE, depositing fine ash in Quetzaltenango (10 km NNE). During 30-31 March and 4-5 April explosions produced ash plumes that rose 400-700 m above the dome and drifted S; ashfall was reported in nearby areas downwind. Avalanches descended the SW and E flanks. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch (Russia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that during 25 March-1 April seismic data at Shiveluch indicated that possible ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. A thermal anomaly on the lava dome was observed in satellite imagery during 25-29 March, and ash plumes drifted 57 km SE on 26 March. Ground-based observers noted that ash-and-gas plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. during 25-30 March. Based on information from KEMSD and analyses of satellite imagery, the Tokyo VAAC reported that on 5 April an eruption produced a plume that rose to an altitude of 7.6 km (23,000 ft) a.s.l. and drifted N. A possible eruption detected in satellite imagery the next day produced a plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted NE. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Soufriere Hills (United Kingdom) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Soufriere Hills Lesser Antilles Volcanic Arc	MVO reported that during 25 March-1 April activity at the Soufrière Hills lava dome was at a low level. A swarm of 36 earthquakes occurred within an hour on 28 March, the largest volcano-tectonic swarm since February 2010. The Hazard Level remained at 3. Source: Montserrat Volcano Observatory (MVO)
Tengger Caldera (Indonesia) | 30 March-5 April 2011 | Continuing ActivityCite this Report
Tengger Caldera Sunda Volcanic Arc	CVGHM reported that during 29 March-4 April brownish-gray ash plumes from Tengger Caldera's Bromo cone rose 400-800 m above the crater and drifted N, E, and NE. Ash fell at the Bromo observation post. Incandescence emanated from the crater and incandescent material was periodically ejected above the crater. Roaring of varying intensity was heard. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were not permitted within a 2-km radius of the active crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

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)