All times are local unless otherwise stated.

Bezymianny (Russia) | 6 April-12 April 2011 | New Activity / Unrest Cite this Report
Bezymianny Eastern Kamchatka Volcanic Arc	KVERT reported that during 1-11 April seismicity from Bezymianny increased. Gas-and-steam activity was observed during 1-2 April; clouds obscured views on the other days. A thermal anomaly over the volcano observed in satellite imagery was weak during 1-3 and 6 April, then increased in size and became more intense. The Aviation Color Code was raised to Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Etna (Italy) | 6 April-12 April 2011 | New Activity / Unrest Cite this Report
Etna Sicily Volcanic Province	INGV-CT reported that from 29 March through the first few days of April, a series of gas-and-ash emissions, rarely with minor incandescent material, rose from the pit crater on the E flank of Etna's SE Crater cone. On 8 April small Strombolian explosions occurred from two vents located in the W portion of the crater floor; ejecta were confined to the crater depression. On 9 April seismicity from the Strombolian activity increased throughout the day. In the afternoon, explosive activity commenced from two vents before lava flows covered the crater floor. Later that evening incandescent blocks appeared within a breach in the E rim of the crater, followed by a small overflow of lava. The lava flow advanced from the base of the SE Crater cone toward the W headwall of the Valle del Bove, as far as 1 km. At the same time small but frequent Strombolian explosions continued within the crater. During the night of 9-10 April, the Strombolian activity within the pit crater gradually increased, as well as volcanic tremor amplitude. The lava flow continued to advance. On 10 April, activity and tremor amplitude significantly increased and culminated with vigorous lava fountaining. An ash-and-gas plume drifted SE, causing ashfall in areas downwind. The lava-flow emission rate also increased dramatically. A second lava flow covered the first and traveled down into the Valle del Bove, essentially following the same path as the lava flows of 12-13 January and 18 February. The lava flow encountered thick snow cover, leading to violent explosive interactions that generated pyroclastic flows, and resulted in spectacular vapor-and-ash plumes. The eruption declined rapidly after about 1500; no activity was observed later than the afternoon. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Kilauea (United States) | 6 April-12 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 rose and fell, 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 spatter from the lake. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Taal (Philippines) | 6 April-12 April 2011 | New Activity / Unrest Cite this Report
Taal Taiwan-Luzon Volcanic Arc	PHIVOLCS reported that field observations of Taal conducted at the E sector inside the main crater lake on 5 April 2011 showed that steaming at the thermal area was weak. The water level had receded 3 mm and the water temperature slightly increased from 30 to 30.5 degrees Celsius. Since the previous measurement on 29 March, the pH value increased indicating that the water had become slightly less acidic. Gas measurements conducted last January, February, and March yielded carbon dioxide emission values (in tonnes per day) of 2,250, 1,875, and 4,670, respectively. On 9 April PHIVOLCS noted that after 31 March the number of earthquakes gradually rose and the depths become more shallow (1-4 km). Steaming at the N and NE sides of the main crater occasionally intensified and was occasionally accompanied by hissing sounds. The Alert Level was raised to 2 (on a scale of 0-5) because of increased seismicity and carbon dioxide emissions. PHIVOLCS warned tourists and residents to avoid Volcano Island. According to news articles, about 100 families had volunteered to evacuate; about 7,000 people remained. Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Philippine Daily Inquirer

Aira (Japan) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	On 6, 9, and 12 April, pilots observed ash plumes from Sakura-jima that rose to altitudes of 2.7-3 km (9,000-10,000 ft) a.s.l. Plumes on 9 April drifted SE and plumes on 12 April drifted S. Based on information from JMA, the Tokyo VAAC reported that during 7-12 April explosions produced plumes that rose to altitudes of 1.2-2.4 km (4,000-8,000 ft) a.s.l. and occasionally drifted NE, E, SE, and S. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Bulusan (Philippines) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Bulusan Eastern Philippine Volcanic Arc	Based on notices from the Manila airport (RPLL), the Tokyo VAAC reported that ash from Bulusan was observed during 7-8 and 11 April. Plumes drifted W on 7 April, and NW and SW on 11 April. PHIVOLCS reported that during breaks in the clouds on 7 April steam plumes were observed rising from the SE and NW thermal vents. Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Tokyo Volcanic Ash Advisory Center (VAAC)
Karymsky (Russia) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported moderate seismic activity at Karymsky during 1-7 April. Seismic data indicated that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. A thermal anomaly was detected in satellite imagery on 2 and 4 April and ash-and-gas plumes drifted in multiple directions as far as 48 km during 1-2 and 4 April. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kizimen (Russia) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported that during 1-7 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 259 km. The Aviation Color Code remained at Orange. Based on analyses of satellite imagery, the Tokyo VAAC reported that a possible eruption on 7 April produced a plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted S. Subsequent images that day and on 8 April showed continuing ash emissions. Another possible eruption on 10 April produced a plume that rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SE. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)
Sheveluch (Russia) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that during 1-7 April seismic data at Shiveluch indicated that possible ash plumes rose to an altitude of 7.5 km (24,600 ft) a.s.l. Ground-based observations during 1-2 April indicated that gas-and-steam plumes containing ash rose to an altitude of 2.7 km (8,800 ft) a.s.l. A thermal anomaly on the lava dome was observed in satellite imagery those same two days. Ash plumes drifted in different directions as far as 187 km during 1-3 and 5 April. The Tokyo VAAC reported that on 7 April a possible eruption detected in satellite imagery produced a plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. Subsequent notices that day stated that ash continued to be detected, and then dissipated. The Aviation Color Code remained at Orange. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)
Suwanosejima (Japan) | 6 April-12 April 2011 | Continuing ActivityCite this Report
Suwanosejima Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima on 12 April produced a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. Source: 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)