All times are local unless otherwise stated.

Ol Doinyo Lengai | 29 March-4 April 2006 | New Activity / Unrest Cite this Report
Ol Doinyo Lengai Tanzania	According to news reports, an eruption began at Ol Doinyo Lengai around 30 March, forcing villagers living near the volcano to evacuate. An article stated that, "Eyewitnesses said they heard a rumbling noise before the volcano began discharging ash and lava, prompting local residents to flee the area in their hundreds. District officials estimated that about 3,000 people from Nayobi, Magadini, Engaruka, Malambo, Ngaresero, Gelai Bomba, and Kitumbeine villages left their homes within a few hours of the eruption..." There were reports of polluted water sources and destroyed vegetation, but no reports of deaths or injuries. Sources: Associated Press, The Guardian News
Ubinas | 29 March-4 April 2006 | New Activity / Unrest Cite this Report
Ubinas Peru	Increased fumarolic activity occurred at Ubinas during the end of March. A Universidad de San Agustin scientist who visited the volcano on 31 March found strong steam-and-ash emissions occurring. Also, leaves of nearby crops were burned and a sound similar to a jet engine emanated from the vent area. Sources: Victor Aguilar, Universidad de San Agustin, Perú, US Geological Survey Volcano Disaster Assistance Program (VDAP)

Arenal | 29 March-4 April 2006 | Continuing ActivityCite this Report
Arenal Costa Rica	OVSICORI reported that on 2 April around 1000 a small pyroclastic flow traveled down Arenal's W flank. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Augustine | 29 March-4 April 2006 | Continuing ActivityCite this Report
Augustine Alaska Peninsula	Low-level eruptive activity continued at Augustine during 24-31 March. Signals continued to be recorded by the seismic network that were associated with occasional hot block-and-ash flows, rock avalanches, rockfalls, and lava flows. Small and dilute ash clouds resulting from these processes were likely confined to the immediate vicinity of the volcano. Satellite imagery continued to show a thermal anomaly related to the new lava dome and lava flow. Airborne sulfur-dioxide gas measurements showed continued high levels of magmatic gas output. Low-light camera observations indicated that activity was restricted mainly to the summit lava dome. Augustine remained at Concern Color Code Orange. Sources: Anchorage Volcanic Ash Advisory Center (VAAC), US Geological Survey Alaska Volcano Observatory (AVO)
Bagana | 29 March-4 April 2006 | Continuing ActivityCite this Report
Bagana Bougainville (Papua New Guinea)	During 16 February to 31 March, activity at Bagana was at moderate levels. Mostly gas emissions occurred, but on 27 March an ash cloud was emitted. During 15-31 March, observers noted moderate-to-bright incandescence, projections of lava fragments, and a lava flow traveling down the volcano's SSW flank. Source: Rabaul Volcano Observatory (RVO) via the Darwin Volcanic Ash Advisory Center
Colima | 29 March-4 April 2006 | Continuing ActivityCite this Report
Colima Mexico	Based on information from the Mexico City MWO, the Colima Observatory, and satellite data, the Washington VAAC reported that there were several eruptions at Colima during 1-3 April. The highest rising resultant ash plume reached ~7.9 km (26,000 ft) a.s.l. after an eruption on 2 April at 1052. Source: Washington Volcanic Ash Advisory Center (VAAC)
Galeras | 29 March-4 April 2006 | Continuing ActivityCite this Report
Galeras Colombia	An increase in the energy of earthquakes at Galeras, which began on 28 March, ended on the 29th. The number of earthquakes beneath the volcano decreased during 28 March to 3 April (an average of 66 earthquakes was recorded daily), in comparison to the previous week (an average of 89 earthquakes was recorded daily). During the report period, steam columns rose up to ~500 m above the volcano (or 15,700 ft a.s.l.) and the outer layer of the lava dome at the volcano's summit cooled in comparison to previous weeks. Galeras remained at Alert Level 2 ("likely eruption in days or weeks"). Source: Servicio Geológico Colombiano (SGC)
Kilauea | 29 March-4 April 2006 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 29 March to 3 April, lava from Kilauea flowed off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit. Small, shallow earthquakes continued beneath the summit area and upper E rift zone at a fluctuating rate. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Langila | 29 March-4 April 2006 | Continuing ActivityCite this Report
Langila New Britain (Papua New Guinea)	During 16 February to 31 March, low-level Vulcanian activity continued at Langila's Crater 2. Eruptive activity was characterized by low-energy emissions of diffuse pale gray ash between 30 January and 7 February. Activity changed to subcontinuous forceful emissions of dark gray ash on 1, 2, 6, 7, and 9 March. The resultant plumes did not rise higher than 2 km above the summit crater (or 10,900 ft a.s.l.) before drifting WSW of the volcano. Weak-to-bright glow and weak projections of incandescent lava fragments were visible on 22, 23, and 28 February, and on 1, 2, and 6 March. There was no activity at Crater 3. Source: Rabaul Volcano Observatory (RVO) via the Darwin Volcanic Ash Advisory Center
Poas | 29 March-4 April 2006 | Continuing ActivityCite this Report
Poas Costa Rica	Following phreatic eruptions that began at Poás on 24 March, seismicity decreased at the volcano by 27 March. In addition, harmonic tremor that was recorded during the heightened activity ceased. As of the 27th, no significant deformation was recorded at the volcano and abundant evaporation continued at Caliente Lake. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Popocatepetl | 29 March-4 April 2006 | Continuing ActivityCite this Report
Popocatepetl Mexico	The Washington VAAC reported that ash from Popocatépetl was visible on satellite imagery on 3 April at 0245 at a height of ~7.3 km (~24,000 ft) a.s.l., drifting S. The Mexico City MWO indicated that there was an eruption around this time that emitted small amounts of ash. Source: Washington Volcanic Ash Advisory Center (VAAC)
Raoul Island | 29 March-4 April 2006 | Continuing ActivityCite this Report
Raoul Island North Kermadec Ridge (New Zealand)	As of 31 March, no new eruptive activity had occurred at Raoul Island after the 17 March eruption. Seismicity continued to decline and Green Lake's water level continued to rise in response to the eruption. Raoul Island remained at Alert Level 2 (minor eruptive activity). Source: GeoNet
Santa Ana | 29 March-4 April 2006 | Continuing ActivityCite this Report
Santa Ana Western El Salvador	During 24-31 March, activity at Santa Ana decreased to low levels in comparison to the previous 4 months of moderate activity. During the report period, seismicity was at relatively low levels, steam plumes occasionally rose ~200 m above the volcano (or 8,400 ft a.s.l.), and the daily sulfur-dioxide flux was between 500 and 1,000 metric tons. The Alert Level remained at red, the highest level, within 5 km of the volcano's summit crater. Source: Servicio Nacional de Estudios Territoriales (SNET)
Soufriere Hills | 29 March-4 April 2006 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	During 24-31 March, lava-dome growth at Soufrière Hills was focused towards the E, with a lava lobe growing in that direction and the majority of rockfalls and pyroclastic flows occurring in the SE and NE sectors of the volcano. The largest pyroclastic flows traveled as far as 2 km NE down Tar River Valley. The sulfur-dioxide flux averaged 523 metric tons per day. Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)
St. Helens | 29 March-4 April 2006 | Continuing ActivityCite this Report
St. Helens Washington	Growth of the new lava dome inside the crater of Mount St. Helens continued during 29 March to 3 April, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. Although the overall level of seismicity remained low, the eruption of lava into the crater continued as was evidenced by ongoing rockfalls and continuous GPS measurements made on the growing lava lobe. St. Helens remained at Volcano Advisory (Alert Level 2); aviation color code Orange. Source: US Geological Survey Cascades Volcano Observatory (CVO)
Tungurahua | 29 March-4 April 2006 | Continuing ActivityCite this Report
Tungurahua Ecuador	During 29 March to 2 April, small-to-moderate explosions at Tungurahua consisted of gas, steam, and small amounts of ash. During the report period, ash fell in the Bilbao, Choglontos, Puela, and Manzano sectors, and incandescent blocks rolled down the volcano's NW flank. Sources: Washington Volcanic Ash Advisory Center (VAAC), Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

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.

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)