All times are local unless otherwise stated.

Asosan | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Asosan Kyushu (Japan)	Based on pilot observations, the Tokyo VAAC reported that on 15 May an ash plume from Aso rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE. JMA reported that the next day plumes rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. A pilot noted that an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted N that same day. During 17-18 May the JMA reported that ash plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E and SE. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Bulusan | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Bulusan Luzon (Philippines)	On 13 May, PHIVOLCS reported that an explosion from Bulusan's summit crater was accompanied by a rumbling sound audible up to 5 km away. The event was recorded by the seismic network as an explosion-type earthquake lasting for about 10 minutes. Cloud cover prevented observations of the summit area. Field investigation conducted immediately after the explosion confirmed the presence of thin ash deposits (0.5- 2.5 mm) approximately 9 km away from the crater in the NW and SW sectors. Several barangays in the municipalities of Juban and Irosin reported light ashfall. The Alert Level remained at 1 (on a scale of 0-5). Entry into the permanent danger zone, defined by a 4-km radius around the volcano, was prohibited. During 15-16 May the seismic network detected four earthquakes. Then, on 16 May, the number of earthquakes rapidly increased to 80 in a seven-hour period. On 17 May PHIVOLCS reported that 144 earthquakes were recorded in the previous 24 hours. Steam rose from the active vents. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Etna | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Etna Sicily (Italy)	Sezione di Catania - Osservatorio Etneo reported that on 8 May mild and discontinuous Strombolian activity resumed at the pit crater located on the E flank of Etna's SE Crater cone. On 11 May volcanic tremor amplitude progressively increased, and at about 2030 lava started to overflow the E crater rim. The activity intensified during the following hours and, shortly before 0400 on 12 May, culminated with lava fountaining which generated an ash cloud that drifted SSE. The lava fountaining lasted around 2 hours, showing a gradual diminution around 0545; an abrupt drop in the volcanic tremor amplitude at 0610 marked the end of the eruptive activity. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Kizimen | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Kizimen Eastern Kamchatka (Russia)	KVERT reported that on 5 and 11 May seismicity from Kizimen was high; seismic data was not collected the other days during 6-13 May because of technical problems. Satellite images showed a large bright thermal anomaly daily on the volcano. During 6-7 May, ash plumes drifted 45 km SE and gas-and-steam plumes drifted 59 km N. Ashfall formed a layer as thick as 1 mm in Milkovo village, 120 km SW, on 10 May. A The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Telica | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Telica Sierra de los Marrabios	Based on reports from INETER, the Washington VAAC stated that emissions of gas-and-ash from Telica were detected on 15 May, and ash fell in areas 4 km N. Seismicity was elevated for a period of time. Source: Washington Volcanic Ash Advisory Center (VAAC)
Tungurahua | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Tungurahua Ecuador	IG reported that, although visual observations of Tungurahua during 11-15 May were often limited due to cloud cover, gas-and-steam plumes were noted during 12-14 May that rose 200-300 m above the crater and drifted E, SE, W, and NW. A small explosion on 15 May produced an ash plume that rose 500 m above the crater and drifted E. An ash plume the next day rose 200 m and drifted E. On 16 May an ash plume rose to an altitude of 8 km (26,200 ft) a.s.l. and drifted E, NE, and N. Incandescent blocks were ejected from the crater and rolled up to 500 m down the flanks. Ashfall was reported in the region of the Negro river. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Ulawun | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Ulawun New Britain (Papua New Guinea)	RVO reported that during 13-14 and 17 May gray-to-brown ash plumes rose above Ulawun. On 17 May the emissions were forceful for a short time and booming noises were reported. Light ashfall was reported in areas between Ubili in the NW and Voluvolu in the NE. Source: Rabaul Volcano Observatory (RVO)
Yasur | 11 May-17 May 2011 | New Activity / Unrest Cite this Report
Yasur Vanuatu	On 12 May, the Vanuatu Geohazards Observatory reported that, based on information collected by the Vanuatu Meteorology and Geohazards Department, satellite imagery showed strong degassing from Yasur during the previous week. Residents living close to the volcano reported persistent strong explosions that were heard and felt on 12 May. The Vanuatu Volcano Alert Level (VVAL) remained at 2 (on a scale of 0-4). Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)

Aira | 11 May-17 May 2011 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	Based on information from JMA, the Tokyo VAAC reported that during 11-18 May explosions from Sakura-jima sometimes produced plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. Plumes occasionally drifted SE and S. During 11, 13-14, and 17 May, pilots observed ash plumes that rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Bagana | 11 May-17 May 2011 | Continuing ActivityCite this Report
Bagana Bougainville (Papua New Guinea)	Based on analyses of satellite imagery, the Darwin VAAC reported that on 16 May an ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 55 km NE. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Batu Tara | 11 May-17 May 2011 | Continuing ActivityCite this Report
Batu Tara Komba Island	Based on analyses of satellite imagery, the Darwin VAAC reported that on 15 and 17 May ash plumes from Batu Tara rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted 75-130 km W and NW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Dukono | 11 May-17 May 2011 | Continuing ActivityCite this Report
Dukono Halmahera	Based on analyses of satellite imagery, the Darwin VAAC reported that during 11-12 May ash plumes from Dukono rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted 75-110 km NE and E. On 16 May an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted over 90 km E. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Karymsky | 11 May-17 May 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka (Russia)	KVERT reported moderate seismic activity at Karymsky during 6-13 May. Possible ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. on 10 May and to an altitude of 4.2 km (13,800 ft) a.s.l. on the other days. Pilots reported that on 6 May ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. Satellite imagery showed a thermal anomaly and ash plumes that drifted 340 km E during 6-7 May. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea | 11 May-17 May 2011 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	HVO reported that two lava lakes at Kilauea were active during 11-17 May. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. Lava from a vent above the south side cascaded down into the lake. A gas plume from the vent generally drifted SW or W and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava mostly from vents near the W edge of the lake continued to fill in a perched lava lake in the center of the crater floor. The lake level fluctuated and occasionally overflowed the edges, sending lava onto the Pu'u 'O'o crater floor. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Novarupta | 11 May-17 May 2011 | Continuing ActivityCite this Report
Novarupta Alaska	Based on analysis of satellite imagery, pilot observations, KVERT reports, and information from AVO, the Anchorage VAAC reported that on 11 May strong winds in the Katmai area re-suspended loose ash deposited during the 1912 eruption. The Volcano Alert Level remained at Normal and the Aviation Color Code remained at Green. Source: Anchorage Volcanic Ash Advisory Center (VAAC)
Popocatepetl | 11 May-17 May 2011 | Continuing ActivityCite this Report
Popocatepetl Mexico	CENAPRED reported steam-and-gas emissions from Popocatépetl during 11-17 May. The emissions occasionally contained small amounts of ash during 14-17 May. Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Santa Maria | 11 May-17 May 2011 | Continuing ActivityCite this Report
Santa Maria Southwestern Guatemala	INSIVUMEH reported that during 12-13 May explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 900 m above Caliente dome and drifted SE, depositing fine ash in areas downwind. During 14-15 May explosions produced ash plumes that rose 2 km above Caliente dome. Pyroclastic flows descended the SW and E flanks. Rumbling noises and block avalanches were also noted. Ash was deposited on the E, S, SW, and W flanks including the communities of Loma Linda, San Marcos, and Palajunoj. During 16-17 May explosions produced ash plumes that rose 0.7-1 km above Caliente dome and drifted SW. A pyroclastic flow traveled E. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch | 11 May-17 May 2011 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	KVERT reported that during 5-7 May seismic data at Shiveluch indicated that possible ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. According to ground-based observations ash plumes rose to an altitude of 7.5 km (24,600 ft) a.s.l. on 7 May and to altitudes of 3-4 km (9,800-13,100 ft) a.s.l. during 5-6 and 8 May. Satellite imagery showed ash plumes drifting 196 km N during 5-6 May. On 7 May small ash clouds drifted S and SE, and gas-and-steam plumes drifted 230 km E. A thermal anomaly was detected during 7-8 May. KVERT noted that the Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 15 May an eruption produced a plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted E. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Soufriere Hills | 11 May-17 May 2011 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	MVO reported that during 6-13 May activity at the Soufrière Hills lava dome was at a low level. On 11 May a pyroclastic flow that occurred in the February 2010 collapse scar traveled about 1 km. An ash cloud rose 1.8 km and drifted NNE, causing light ashfall in Lookout village. The Hazard Level remained at 3. Source: Montserrat Volcano Observatory (MVO)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,363 individual reports over 1,185 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)