All times are local unless otherwise stated.

Merapi | 26 April-2 May 2006 | New Activity / Unrest Cite this Report
Merapi Central Java	On 28 April, CVGHM observed a lava flow from Merapi traveling ~1.5 km SW to the Lamat River. On the 28th, seismicity was dominated by multiphase earthquakes. Signals from landslides, rockfalls, and low-frequency events were also recorded. According to news reports, around 27 April nearly 2,000 villagers were evacuated from Sidorejo and Tegalmulyo villages on the volcano's flanks. On the 27th, small amounts of ash fell in Gemer village about 5 km from Merapi's summit. Merapi remained at Alert Level 3 (on a scale of 1-4). Sources: People's Daily Online (China), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Reuters
Ubinas | 26 April-2 May 2006 | New Activity / Unrest Cite this Report
Ubinas Peru	According to INGEMMET, on 22 April at 0715 an explosion began at Ubinas that produced an ash-and-gas plume that reached a height between 1 and 3 km above the volcano (or 21,900 and 28,450 ft a.s.l.). This was the highest rising plume since activity began in late March. Continuous emissions occurred until 1600. Ash and gas emitted during 20-22 April traveled as far as 60 km from the volcano mainly NW, W, and SW, and traces of ash reached the Arequipa airport. During 25 and 26 April, the volume of ash emitted from the volcano decreased significantly. Gas plumes rose between 200 and 700 m above the volcano's caldera (or 19,300 and 20,900 ft a.s.l.). The Alert Level was reduced from Orange to Yellow. Seismicity during 22-26 April was higher than normal. The Buenos Aires VAAC posted volcanic ash advisories during the report period. Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET), Buenos Aires Volcanic Ash Advisory Center (VAAC)

Aira | 26 April-2 May 2006 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	Based on information from JMA, the Tokyo VAAC reported that an explosion at Sakura-jima on 28 April produced an ash plume that rose to 2.1 km (7,000 ft) a.s.l. An explosion on 1 May produced a plume that rose to an unknown height. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Augustine | 26 April-2 May 2006 | Continuing ActivityCite this Report
Augustine Alaska Peninsula	AVO reduced the Concern Color Code at Augustine from Orange to Yellow on 28 April. As of the 28th, instrumental and visual observations indicated that the growth of the summit lava dome and lava-flow emissions had stopped, or continued at very low rates. Seismic data showed that rockfalls and avalanches occurred at a diminished level. No changes were seen at the summit during the previous several weeks. AVO warned that despite the apparent cessation of lava-dome growth, the new dome and lava flows are still highly unstable, and rockfalls and avalanches are still occurring and may continue for several weeks or months. Sources: Anchorage Volcanic Ash Advisory Center (VAAC), US Geological Survey Alaska Volcano Observatory (AVO)
Barren Island | 26 April-2 May 2006 | Continuing ActivityCite this Report
Barren Island Andaman Islands (India)	A plume emitted from Barren Island was visible on satellite imagery on 2 May at a height near 3.7 km (12,000 ft) a.s.l. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Bulusan | 26 April-2 May 2006 | Continuing ActivityCite this Report
Bulusan Luzon (Philippines)	According to news reports, on 29 April at 1044 an explosion at Bulusan produced an ash plume that rose ~1.6 km above the volcano (or 10,400 ft a.s.l.). Ash fell on nearby villages. People are not permitted to enter within 4 km of the volcano's crater. Sources: Agence France-Presse (AFP), INQ7.net
Galeras | 26 April-2 May 2006 | Continuing ActivityCite this Report
Galeras Colombia	INGEOMINAS reported that Galeras remained at a critical state during 21 April to 1 May, with a partially solidified lava dome in the main crater and low levels of seismicity. The sulfur-dioxide flux continued at low levels. Galeras remained at Alert Level 2 (likely eruption in days or weeks). Source: Servicio Geológico Colombiano (SGC)
Karymsky | 26 April-2 May 2006 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka (Russia)	Intermittent eruptive activity continued at Karymsky during 21-28 April. Based on interpretations of seismic data, ash plumes rose to a height of ~3.8 km (12,500 ft) a.s.l. during the report week. Satellite imagery showed a large thermal anomaly at the volcano's crater, and numerous ash plumes and deposits extending 10-200 km SE and E of the volcano. Karymsky remained at Concern Color Code Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea | 26 April-2 May 2006 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 26 April to 2 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Continuous low-level volcanic tremor was recorded at Kilauea's summit, accompanied by a few small earthquakes. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Lascar | 26 April-2 May 2006 | Continuing ActivityCite this Report
Lascar Northern Chile	Based on information from a significant meteorological forecast (SIGMET), the Buenos Aires VAAC reported that on 28 April a W-drifting ash cloud was observed at a height around 6.1-7.6 km (20,000-25,000 ft) a.s.l. The Aviation Color Code was at Red. Later that day activity was no longer observed and the Aviation Color Code was reduced to Green. Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)
Manam | 26 April-2 May 2006 | Continuing ActivityCite this Report
Manam Northeast of New Guinea	Ash from Manam was observed on satellite imagery on 28 April at a height of ~3 km (10,000 ft) a.s.l. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Raoul Island | 26 April-2 May 2006 | Continuing ActivityCite this Report
Raoul Island North Kermadec Ridge (New Zealand)	Hydrothermal activity at Raoul Island's Green Lake crater had declined significantly as of 28 April and the lake water level continued to fall. The Alert Level at Raoul Island was reduced from 2 to 1 (some signs of volcano unrest), on a scale of 0-5. Source: GeoNet
San Cristobal | 26 April-2 May 2006 | Continuing ActivityCite this Report
San Cristobal Sierra de los Marrabios	Phreatomagmatic eruptions began at San Cristóbal on 21 April. Seismic tremor increased at the volcano that same day around 1300. Small explosions produced gas-and-ash plumes during 21-23 April that deposited small amounts of ash in nearby towns. Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Soufriere Hills | 26 April-2 May 2006 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	Observations of Soufrière Hills during 21-28 April revealed that lava extrusion continued. Dome growth occurred over a sector extending SW to NE. The eastward facing lobe continued to grow on the NE side of the dome and a central spine was observed on 28 April. Small rockfalls and pyroclastic flows continued to initiate from the active E flank of the dome, adding to the talus in the upper reaches of the Tar River Valley. Rockfalls were accompanied by minor ash venting. Thermal images taken on 27 April indicated some very hot (in excess of 400°C) areas on the E flank of the dome. During the report period seismicity was dominated by rockfalls, as has been the case throughout the on-going phase of dome growth. The sulfur-dioxide flux averaged 520 metric tons per day, close to the long-term average for the entire eruption. Sources: Washington Volcanic Ash Advisory Center (VAAC), Montserrat Volcano Observatory (MVO)
St. Helens | 26 April-2 May 2006 | Continuing ActivityCite this Report
St. Helens Washington	Growth of the new lava dome inside the crater of Mount St. Helens continued during 26 April to 2 May, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. Seismicity continued as very small periodic earthquakes, recurring every few minutes, punctuated by occasional larger earthquakes. The active lava dome continued to build towards the W. St. Helens remained at Volcano Advisory (Alert Level 2); aviation color code Orange. Source: US Geological Survey Cascades Volcano Observatory (CVO)
Tungurahua | 26 April-2 May 2006 | Continuing ActivityCite this Report
Tungurahua Ecuador	During 28 April-1 May, small-to-moderate explosions at Tungurahua produced gas, steam, and small amounts of ash. Seismicity was at relatively high levels. A plume rose to a maximum height of ~2 km above the volcano (or 23,050 ft a.s.l.) on 28 April. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC)

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)