All times are local unless otherwise stated.

Erta Ale | 21 September-27 September 2005 | New Activity / Unrest Cite this Report
Erta Ale Ethiopia	According to unconfirmed reports from local authorities, Erta Ale began erupting on 24 September after a series of earthquakes occurred along the Afar western margin on the previous day. The earthquakes, with a maximum magnitude of 5.5, were recorded at the Geophysical Observatory of Addis Ababa University. A group of geologists and geophysicists were planning to travel to the field to make observations. Source: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University
Sheveluch | 21 September-27 September 2005 | New Activity / Unrest Cite this Report
Sheveluch Central Kamchatka (Russia)	KVERT raised the Concern Color Code at Shiveluch from Orange to Red (the highest level) on 22 September. According to interpretations of seismic data, on the 22nd at 1715 a strong eruption began, with ash plumes reaching ~7.5 km (24,600 ft) a.s.l. [corrected by KVERT to 6.5 km (21,300 ft) a.s.l.] and hot avalanches and pyroclastic flows descending the volcano's flanks. The pyroclastic flows extended 10-15 km. The strongest seismic signal of the eruption occurred on 22 September at 2259. Shallower signals recorded between 22 September at 2330 and 23 September at 1200 were possibly associated with ash emissions that rose to 3.5 km (11,500 ft) a.s.l. An ash plume was visible on satellite imagery at a height of ~3 km (9,850 ft) a.s.l. extending ~20 km SSW. The Concern Color Code was reduced to Orange on 23 September. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bagana | 21 September-27 September 2005 | Continuing ActivityCite this Report
Bagana Bougainville (Papua New Guinea)	Ash was emitted from Bagana during 17-18 September and drifted W and NW. During 14-18 September, incandescence from the volcano was visible at night. On the 18th, observers described what could have been cascading volcanic material detached from a possible active lava flow. Source: Rabaul Volcano Observatory (RVO)
Barren Island | 21 September-27 September 2005 | Continuing ActivityCite this Report
Barren Island Andaman Islands (India)	A pilot observed a plume emitted from Barren Island on 23 September around 1230 at a height of ~3 km (10,000 ft) a.s.l., extending ~90 km E. On 27 September, a low-level plume was visible on satellite imagery drifting NE. The current eruption of Barren Island began on 28 May 2005. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Colima | 21 September-27 September 2005 | Continuing ActivityCite this Report
Colima Mexico	During 22-27 September, several small explosions occurred at Colima. The largest explosion took place on 27 September at 0507 and produced a plume to a height of ~3.8 km above the volcano (or 25,100 ft a.s.l.). The plume drifted WSW, depositing small amounts of ash in the cities of Colima, Villa de Alvarez, and Comala more than 30 km from the volcano. Due to the threat of lahars forming on the volcano's flanks, Universidad de Colima advised avoiding the ravines of La Lumbre, San Antonio, Monte Grande (in Colima state), and La Arena (in Jalisco state). Source: Centro Universitario de Estudios Vulcanológicos (CUEV) - Universidad de Colima
Kilauea | 21 September-27 September 2005 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 22-27 September, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Langila | 21 September-27 September 2005 | Continuing ActivityCite this Report
Langila New Britain (Papua New Guinea)	During 12-18 September, Langila's Crater 2 continued to forcefully erupt ash at irregular intervals. The resultant ash plumes drifted NW and W. Incandescence and weak projections of volcanic material were visible on the evening of 13 September. There was no activity at Crater 3. Seismicity was at low levels at the volcano, consisting mainly of low-frequency earthquakes. Source: Rabaul Volcano Observatory (RVO)
Manam | 21 September-27 September 2005 | Continuing ActivityCite this Report
Manam Northeast of New Guinea	During 12-18 September, Manam's Main Crater continued to release weak emissions of ash. For a brief period on the 17th, a moderate amount of ash was emitted. Ash plumes drifted to the NW part of the island. Manam remained at Alert Level " Stage 1." Source: Rabaul Volcano Observatory (RVO)
Rabaul | 21 September-27 September 2005 | Continuing ActivityCite this Report
Rabaul New Britain (Papua New Guinea)	During 12-18 September, ash emissions continued at Rabaul caldera's active Tavurvur cone. Ash plumes rose 800-1,500 m above the volcano (or 4,900-7,200 ft a.s.l.) and drifted N and NW, depositing ash in most parts of Rabaul Town and beyond. Projections of incandescent volcanic material were visible at night during strong explosions. Seismicity was at moderate-to-high levels, with most earthquakes associated with ash emissions and explosions. The deformation trend generally reflected uplift. People were discouraged from venturing within 1 km of the erupting vent. Source: Rabaul Volcano Observatory (RVO)
Reventador | 21 September-27 September 2005 | Continuing ActivityCite this Report
Reventador Ecuador	During 21-27 September, there were intermittent emissions of ash from Reventador, with the highest rising plumes reaching ~8.5 km (28,000 ft) a.s.l. on 24 September. Hot spots were occasionally visible on satellite imagery during the report week. Source: Washington Volcanic Ash Advisory Center (VAAC)
Santa Ana | 21 September-27 September 2005 | Continuing ActivityCite this Report
Santa Ana Western El Salvador	During 21-26 September, seismicity and gas emissions were above normal levels at Santa Ana as they had been since 27 July. Microseismicity remained at relatively high levels. During the report period, gas plumes rose to a maximum height of ~1 km above the volcano (or 11,000 ft a.s.l.) on 26 September. During a visit to the crater on 21 September, observers noted that the summit crater lagoon had become greener and small rock slides occurred in a fumarolic area. Santa Ana remained at Alert Level Yellow Phase 1. Source: Servicio Nacional de Estudios Territoriales (SNET)
Soufriere Hills | 21 September-27 September 2005 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	Volcanic and seismic activity at Soufrière Hills remained at elevated levels during 16-23 September. Observations on 20 September suggested that slow lava-dome growth continued. The daily sulfur-dioxide flux averaged 680 metric tons per day (t/d), above the long-term eruption average of 500 t/d. Source: Montserrat Volcano Observatory (MVO)
Spurr | 21 September-27 September 2005 | Continuing ActivityCite this Report
Spurr Alaska Peninsula	Seismicity at Spurr during 16-23 September remained above background levels, but the overall rate continued to gradually decline. Preliminary data from a gas-sensing flight earlier in the week showed a substantial reduction in gas emissions compared to previous measurements taken in May 2005. The declining seismicity, reduced gas emission, and the changing summit-lake color (thought to reflect lower levels of acidity), all suggested a reduced level of volcanic activity. Minor steaming continued from the summit "melt pit" and occasionally from Crater Peak. Spurr remained at Concern Color Code Yellow. Source: US Geological Survey Alaska Volcano Observatory (AVO)
St. Helens | 21 September-27 September 2005 | Continuing ActivityCite this Report
St. Helens Washington	Growth of the new lava dome inside the crater of Mount St. Helens continued during 21-26 September, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. There were no significant changes in seismicity or deformation during the report period. Time-series images showed that the active northwestern portion of the new lava dome continued to move westward into the W arm of a glacier, spawning rockfalls. St Helens remained at Volcano Advisory (Alert Level 2); aviation color code Orange. Source: US Geological Survey Cascades Volcano Observatory (CVO)
Suwanosejima | 21 September-27 September 2005 | Continuing ActivityCite this Report
Suwanosejima Ryukyu Islands (Japan)	Based on information from JMA, the Tokyo VAAC reported that an emission from Suwanose-jima on 22 September reached a height of ~1.8 km (6,000 ft) a.s.l. and drifted W. Ash was not visible on satellite imagery. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Tungurahua | 21 September-27 September 2005 | Continuing ActivityCite this Report
Tungurahua Ecuador	During 21-26 September, volcanic activity at Tungurahua remained at low levels with small emissions of steam, gas, and variable ash content. A small amount of ash fell in the towns of Cusúa (NW) and Bilbao (8 km W of the volcano) during the morning of 21 September. Fumaroles on the outer edge of the crater were visible from Runtún after not being seen for 6 months. Steam-and-gas plumes rose ~ 1 km above the volcano (or 19,800 ft a.s.l.) and drifted W. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Veniaminof | 21 September-27 September 2005 | Continuing ActivityCite this Report
Veniaminof Alaska Peninsula, Alaska	Cloudy weather during 16-23 September prohibited web camera and satellite observations of Veniaminof, but seismic data indicated diminishing activity. Some minor ash emissions may have occurred, with diffuse ash plumes rising less than ~3 km (10,000 ft) a.s.l. Veniaminof remained at Concern Color Code Yellow. Source: US Geological Survey Alaska Volcano Observatory (AVO)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,976 individual reports over 1,214 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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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)