All times are local unless otherwise stated.

Bagana (Papua New Guinea) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Bagana Solomon Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that on 23 August an ash plume from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 93 km SW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Etna (Italy) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Etna Sicily Volcanic Province	Sezione di Catania - Osservatorio Etneo reported that nine days after the previous episode, the New SE Crater produced its twelfth paroxysmal eruptive episode of 2011 during the early morning of 29 August. The event was preceded by an explosion at 2252 on 27 August, and a series of ash emissions from the New SE Crater almost 15 hours later. Weak Strombolian activity visible during the evening on 28 August intensified during the night. At 0115 on 29 August lava overflowed the rim through a breach in the E crater rim and traveled towards the Valle del Bove. Strombolian activity progressively intensified and two vents within the crater emitted pulsating lava fountains up to 100 m high. The lava fountains again increased in height and a dense plume rose a few kilometers above the summit before drifting toward the SSE. At the same time, a small lava flow issued from the area affected by the collapse of a portion of the cone's ESE flank during the 20 August paroxysm. At 0220 the SE flank of the cone fractured and exposed a line of new eruptive vents down to the base of the cone that produced lava fountains. A broad lava flow fed by the vents descended into the Valle del Bove, somewhat to the S of the lava flow emitted earlier during the episode. The lava fountaining from the vents within the crater turned into ash emission just after 0220, whereas the lowest vent on the new eruptive fracture continued to produce incandescent jets until 0250. Ash emission continued at a diminishing rate until about 0315. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Kilauea (United States) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 24-30 August, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated but remained below the inner ledge 75 m below the crater floor. At Pu'u 'O'o' crater, lava from sources on the E and S portions of the crater floor fed a lava lake that was formed during 25-26 August. A new source opened at the W edge of the crater floor during 29-30 August, and lava quickly spread N and S along the base of the W crater wall. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Papandayan (Indonesia) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Papandayan Sunda Volcanic Arc	On 26 August CVGHM reported that Papandayan showed minor to no changes in recent seismicity, deformation, geochemistry, and visual observations; therefore the Alert Level remained at 3 (on a scale of 1-4). Seismicity remained high, but stable, and was dominated by shallow volcanic earthquakes. Deformation measurements showed no change, and water temperatures in multiple fumarolic areas and lakes remained relatively unchanged. Sulfur dioxide gas emissions decreased from 8 tons per day on 12 August to 6 tons per day on 23 August. Carbon dioxide in the soil at a 1 m depth in multiple areas did not increase. Visitors and residents were advised not to venture within 2 km of the active crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Ranakah (Indonesia) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Ranakah Sunda Volcanic Arc	CVGHM reported that observers of Anak Ranakah, a lava dome that formed in 1987 at the base of the large older lava dome of Ranakah, noted white plumes rising up to 10 m high during January-24 August. Seismicity initially increased in December 2010, but increased again during June-August. Based on visual observations and seismic data analyses, CVGHM raised the Alert Level to 2 (on a scale of 1-4) on 26 August. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Tambora (Indonesia) | 24 August-30 August 2011 | New Activity / Unrest Cite this Report
Tambora Sunda Volcanic Arc	Based on visual observation and seismic data, CVGHM reported an increase in activity at Tambora during the previous five months. Ground-based observers at an observation post in Tambora village noted dense white plumes rising 50-75 m above the caldera rim during April and June, but no plumes during May or July. In August dense white plumes rose 20 m above the caldera rim. Seismicity started to increase in April and continued to increase through August. On 30 August the Alert Level was raised to 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Aira (Japan) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that during 23-30 August explosions from Sakura-jima produced plumes that rose to altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. and drifted SW, W, NW, N, and NE. On 30 August a pilot observed an ash plume that rose to an altitude of 1.2 km (4,000 ft) a.s.l. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Batu Tara (Indonesia) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Batu Tara Sunda Volcanic Arc	Based on analyses of satellite imagery, the Darwin VAAC reported that during 23-30 August ash plumes from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 20-90 km N, NW, and W. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Karymsky (Russia) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported that during 19-26 August moderate seismic activity continued at Karymsky, indicating that possible ash plumes rose to an altitude of 5.2 km (17,000 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite during 21-25 August. Gas-and-steam plumes containing ash drifted 18 and 65 km E on 18 and 24 August, respectively. The Aviation Color Code remained at Orange. Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 29 August an ash plume rose to an altitude of 7.3 km (24,000 ft) a.s.l. and drifted E. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)
Kizimen (Russia) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Kizimen Eastern Kamchatka Volcanic Arc	KVERT reported that during 19-26 August seismicity from Kizimen was above background levels; volcanic-tremor magnitude gradually increased and several hundred earthquakes were detected the previous week. Video images showed moderate fumarolic activity. A lava flow on the E flank was active. Satellite images showed a large bright thermal anomaly on the volcano all week and gas-and-steam plumes that drifted E on 19 and 22 August. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Lokon-Empung (Indonesia) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Lokon-Empung Sangihe Volcanic Arc	According to a news article, activity from Tompaluan crater, in the saddle between the Lokon-Empung peaks, decreased on 29 August after erupting several times the previous week and specifically 12 times on 28 August. One explosion on 29 August ejected material 250 m above the crater. The article also noted that 222 people remained at temporary refugee camps because their homes were located within 3 kilometers of the crater. Source: BNO News
Popocatepetl (Mexico) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Popocatepetl Trans-Mexican Volcanic Belt	CENAPRED reported that, although cloud cover often prevented observations of Popocatépetl during 24-30 August, steam-and-gas emissions were occasionally noted. Based on reports from CENEPRED and the Mexico City MWO, the Washington VAAC reported ash emissions during 28-29 August. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
Puyehue-Cordon Caulle (Chile) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Puyehue-Cordon Caulle Andean Southern Volcanic Arc	Based on seismicity during 24-25 August, 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. A predominantly white plume observed by an area camera rose 1 km above the crater. The seismic network detected four explosions that caused the plume to turn gray. Ashfall was reported in Temuco. The Alert Level remained at Red. Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Sheveluch (Russia) | 24 August-30 August 2011 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that seismic activity at Shiveluch was moderate during 19-26 August, and indicated that possible ash plumes rose to an altitude of 8.2 km (26,900 ft) a.s.l. on 23 August. A thermal anomaly on the volcano was observed in satellite imagery on 18, 21, and 25 August. The Aviation Color Code remained at Orange. Based on information from KEMSD and analyses of satellite imagery, the Tokyo VAAC reported that on 29 August an eruption produced a plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted E. Subsequent images that day showed that continuing ash emissions had later dissipated. According to a news article, international flights were re-routed that day due to ash plumes that reportedly rose to an altitude of 8.6 km (28,000 ft) a.s.l. Sources: IOL News, Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,322 individual reports over 1,229 weeks (average of 17 per week) on 336 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)