All times are local unless otherwise stated.

Apoyeque | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Apoyeque Nicaragua	INETER reported that a seismic swarm near Apoyeque started at 1627 on 6 September in an area between the volcano and Managua (less than 10 km SW). At the time of the report, almost four hours after the start of the event, 17 earthquakes had been detected; three events were M 2.3-3.7, at depths ranging from 2.8 to 6 km. No earthquakes were recorded on 9 September. Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Etorofu-Yakeyama [Grozny Group] | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Etorofu-Yakeyama [Grozny Group] Iturup (Etorofu) Island (Japan/Russia)	Based on visual observations and analyses of satellite imagery, SVERT reported that during 4-10 September fumarolic activity at Grozny Group increased. The Aviation Color Code remained at Yellow. Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Krakatau | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Krakatau Sunda Strait	According to NASA's Earth Observatory, a satellite image of Krakatau acquired on 4 September showed fresh lava flows descending the SE flank of Anak Krakatau, extending the shoreline by about 100 m. Source: NASA Earth Observatory
Little Sitkin | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Little Sitkin Aleutian Islands (USA)	AVO reported that during 5-11 September seismic activity at Little Sitkin was much lower than the peak of activity during 29-30 August, but continued to remain elevated. Satellite views were obscured by clouds during 5 and 8-11 September. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory. Source: US Geological Survey Alaska Volcano Observatory (AVO)
San Cristobal | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
San Cristobal Sierra de los Marrabios	INETER reported that on 8 September three explosions from San Cristóbal produced ash-and-gas plumes that rose 1.5 km above the crater and drifted 9 km/hr NW. Ashfall was reported in El Viejo (18 km WSW), El Chonco, and Ranchería. Sporadic explosions later that day generated ash plumes that rose 1.5-5 km and drifted 50 km WNW. Ash fell in an area covering 2,438 square kilometers, including the communities of El Viejo, La Grecia, La Joya, Santa Catalina, El Piloto, Las Banderas, Las Rojas, Carlos Fonseca, Jiquilillo, Mechapa, and Cosiguina. Ashfall was 5 cm thick in areas near the crater and up to 3 mm thick in more distant places. Sulfur dioxide emissions were 3,221 tons per day, well above the normal range of 550 to 700 tons per day. A resident near the volcano reported landslides and falling rocks in the N part of the crater. Incandescent rocks fell in areas NW, causing burns on livestock. Residents in Versalles Arriba, near the crater, reported seeing a fissure. According to a news article, officials evacuated about 3,000 people. SINAPRED reported that airplanes were diverted around San Cristóbal to other airways. Sources: Associated Press, Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED), Instituto Nicaragüense de Estudios Territoriales (INETER)
Soufriere Hills | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Soufriere Hills Montserrat	MVO reported that during 31 August-7 September activity at the Soufrière Hills lava dome was at a low level, although seismicity remained slightly elevated. Clear views of parts of the dome showed very little change, apart from some modification to the steep eastern face from the formation of the pyroclastic flow on 29 August. The Hazard Level remained at 2 (on a scale of 1-5). Source: Montserrat Volcano Observatory (MVO)
Tangkuban Parahu | 5 September-11 September 2012 | New Activity / Unrest Cite this Report
Tangkuban Parahu Western Java	CVGHM reported that seismicity at Tangkubanparahu had increased significantly on 13 August, then again on 23 August; seismicity fluctuated and remained elevated through 6 September. Earthquakes were located 0.5-4 km beneath Ratu Crater and in an area W at depths of 4-12 km. Soil temperatures at Ratu Crater showed an increasing trend on 31 August, but had gradually declined by 5 September. Sulfur dioxide gas emissions were high in an area NW of the crater, causing CVGHM to remind visitors not to approach the crater within a 1.5-km radius. Based on seismicity, visual observations, gas measurements, and crater lake water temperatures through 7 September, the Alert Level remained at 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Aira | 5 September-11 September 2012 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	JMA reported that during 3-7 September six explosive eruptions from Sakura-jima's Showa Crater ejected tephra as far as 1.3 km from the crater. Incandescence from the crater was observed at night. Based on information from JMA, the Tokyo VAAC reported that explosions during 6-11 September often produced plumes that rose to altitudes of 1.8-4.6 km (6,000-15,000 ft) a.s.l. The plumes sometimes drifted N, NE, and SE. On 10 September a pilot observed an ash plume that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted E. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Japan Meteorological Agency (JMA)
Batu Tara | 5 September-11 September 2012 | Continuing ActivityCite this Report
Batu Tara Komba Island	Based on analyses of satellite imagery, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that during 5-11 August ash plumes from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 55-75 km W, WNW, and NW. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Cleveland | 5 September-11 September 2012 | Continuing ActivityCite this Report
Cleveland Chuginadak Island (USA)	On 5 September, AVO reported that satellite views of Cleveland showed no evidence of further eruptive activity since the last explosion on 20 August. Fresh lava within the summit crater was last detected in images in early May. The Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Fuego | 5 September-11 September 2012 | Continuing ActivityCite this Report
Fuego South-Central Guatemala	In a special bulletin on 4 September at 1700, INSIVUMEH reported that the eruption from Fuego that began 32 hours earlier had ended. During 6-11 September fumarolic plumes rose 100-150 m above the crater and drifted W and NW. Weak explosions generated ash plumes that rose 300-400 m above the crater and drifted W and NW. During 8-9 September incandescent tephra was ejected to a height of 100 m and caused avalanches in the Taniluyá and the Ceniza (SSW) drainages. A 10-20-m-wide lahar traveled SE down the Las Lajas drainage on 9 September, carrying tree trunks and blocks 1.5 m in diameter. During 10-11 September a lava flow traveled 100 m down the Taniluyá drainage. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Gamkonora | 5 September-11 September 2012 | Continuing ActivityCite this Report
Gamkonora Halmahera	CVGHM reported that on 7 September the Alert Level for Gamkonora was lowered from 3 to 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Karymsky | 5 September-11 September 2012 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka (Russia)	KVERT reported weak-to-moderate seismic activity from Karymsky during 31 August-7 September. Seismic data indicated that ash plumes possibly rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 31 August and 1 September. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea | 5 September-11 September 2012 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 5-11 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. On 4 September HVO geologists observed the Pu'u 'O'o Crater floor and noted lava ponds in the E and S pits, with the N pit being fully crusted over. During 5-11 September glow emanated from the E and S pit craters; lava in the N pit was crusted, but was periodically incandescent on the W edge. A collapse in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow. Lava flows were active above and at the top of the pali. On 11 September a geologist confirmed that lava flows above the pali had advanced to the top of the abandoned Royal Gardens subdivision. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Machin | 5 September-11 September 2012 | Continuing ActivityCite this Report
Machin Colombia	According to INGEOMINAS, Observatory Vulcanológico and Sismológico de Manizales reported that at 0732 on 9 September a M 3.6 volcano-tectonic earthquake occurred below the main lava dome at Cerro Machín at a depth of 3.2 km, and was felt by nearby residents. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity"). Source: Servicio Geológico Colombiano (SGC)
Nevado del Ruiz | 5 September-11 September 2012 | Continuing ActivityCite this Report
Nevado del Ruiz Colombia	According to INGEOMINAS, on 5 September the Observatorio Vulcanológico and Sismológico de Manizales reported that seismicity at Nevado del Ruiz significantly decreased, both in the number and magnitude of the earthquakes. Field measurements and analysis of satellite imagery continued to show a significant amount of sulfur dioxide in the atmosphere. A steam-and-gas plume rose 400 m and drifted W. Later that day, INGEOMINAS decreased the Alert Level to III (Yellow; "changes in the behavior of volcanic activity"). Source: Servicio Geológico Colombiano (SGC)
Paluweh | 5 September-11 September 2012 | Continuing ActivityCite this Report
Paluweh N of Flores Island	CVGHM reported that on 7 September the Alert Level for Paluweh was lowered from 2 to 1 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Sheveluch | 5 September-11 September 2012 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	Based on visual observations and analyses of satellite data, KVERT reported that during 31 August-7 September a viscous lava flow continued to effuse on the NE flank of Shiveluch's lava dome, and was accompanied by hot avalanches and fumarolic activity. Satellite imagery showed a thermal anomaly over the lava dome during 31 August and 4-5 September; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Sirung | 5 September-11 September 2012 | Continuing ActivityCite this Report
Sirung Pantar Island	CVGHM reported that on 7 September the Alert Level for Sirung was lowered from 2 to 1 (on a scale of 1-4). 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 19,996 individual reports over 1,215 weeks (average of 16 per week) on 332 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)