All times are local unless otherwise stated.

Bagana (Papua New Guinea) | 21 April-27 April 2004 | New Activity / Unrest Cite this Report

Bagana Bougainville Volcanic Arc

A helicopter pilot reported to RVO that new lava was being emitted from Bagana around 1240 on 27 April. According to information from the village of Torokina, the lava flow was estimated to be about 8-9 km from the village. RVO was uncertain about the local topography between the volcano and Torokina, and therefore could not assess the degree of danger for the residents of the village from the lava flow. RVO has no monitoring equipment at Bagana. Source: Rabaul Volcano Observatory (RVO)

Aira (Japan) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	Based on information from JMA, the Tokyo VAAC reported that an eruption of Sakura-jima on 25 April produced an ash plume that rose to a height of ~2.4 km a.s.l. and extended N. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Anatahan (United States) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Anatahan Mariana Volcanic Arc	Seismicity at Anatahan increased abruptly on 24 April at 1052 to a level that had not been reached since the summer of 2003. Around 0600 on 26 April, seismicity leveled off. Later that day, during two 30-minute observation periods, scientists saw regular puffs of yellow/brown steam and ash emitted at 1- to 2-minute intervals. The rate of emissions virtually matched the rate of seismic events during that time. During 24-26 April, steam-and-ash plumes reached a maximum height of about 600 m above the volcano. According to the Washington VAAC, on 24 April a thin plume from Anatahan was visible on satellite imagery ~1 km above the volcano and extending NW from the volcano. Aircraft were warned to proceed with caution near the volcano. Sources: Washington Volcanic Ash Advisory Center (VAAC), Agence France-Presse (AFP), Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
Dukono (Indonesia) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	During 21-27 April, Dukono occasionally emitted ash plumes that were visible on satellite imagery. Plumes rose to heights of ~3 km a.s.l. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Fuego (Guatemala) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Fuego Central America Volcanic Arc	During 22-27 April, weak explosions at Fuego produced gas-and-steam clouds to ~1 km above the volcano. In addition, small avalanches of volcanic material occasionally traveled W toward Santa Teresa Ravine. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Karymsky (Russia) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	Seismicity was above background levels at Karymsky during 16-23 April, with 240-450 shallow earthquakes occurring per day. Based on interpretations of seismic data, ash-and-gas explosions may have produced plumes to 2.5-3.5 km a.s.l. daily. On 17 and 20 April, ash deposits were seen NW, SW, and E of the volcano. On 19 April, an ash plume was seen on satellite imagery extending 47 km S. Karymsky remained at Concern Color Code Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea (United States) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 22-27 April, lava from Kilauea continued to slowly flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. During most of the report period, tremor was at low levels at Kilauea's summit. Tremor was at moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Santa Maria (Guatemala) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	During 22-27 April, explosions at Santa María's Santiaguito lava-dome complex produced gas-and-ash plumes that rose to ~1 km above the crater. Small avalanches of incandescent volcanic material descended the SW side of the Caliente dome. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Semeru (Indonesia) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Semeru Sunda Volcanic Arc	The Darwin VAAC reported that an ash plume from Semeru was visible on satellite imagery on 21 April. The plume rose to ~4.6 km a.s.l. and drifted ESE. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Sheveluch (Russia) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	Seismicity was above background levels at Shiveluch during 16-23 April, with a large number of weak earthquakes occurring 0-5 km beneath the active lava dome and ten M 1.5-2.7 earthquakes. Based on interpretations of seismic data, during 15-18, and 21 April six ash-and-gas explosions may have produced plumes to 4-7 km a.s.l. The highest rising observed plume (8 km a.s.l.) was produced from an ash-and-gas explosion on 18 April. Shiveluch remained at Concern Color Code Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Soufriere Hills (United Kingdom) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Soufriere Hills Lesser Antilles Volcanic Arc	Volcanic and seismic activity at Soufrière Hills were at low levels during 16-23 April. Seismicity was characterized by periods of continuous and spasmodic tremor punctuated by long-period hybrid earthquakes. Continuous low-level tremor occurred on 16 April with a second episode during 18-19 April. The sulfur-dioxide flux varied during the report period, reaching a peak of 1,030 metric tons per day on 16 April. Source: Montserrat Volcano Observatory (MVO)
Tungurahua (Ecuador) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Tungurahua Northern Andean Volcanic Arc	Volcanic activity at Tungurahua during 22-26 April was at moderate levels. On 21 April, a column of steam, gas, and ash rose to a height of ~1 km above the volcano and drifted NW. Ash fell in Bilbao, Cusúa, San Juan, Cotaló, Pillate, and Juive sectors. A plume reached ~0.5 km on 22 April and deposited ash in the towns of Ambato (to the NW) and Baños (to the N). During the evening of 24 April, incandescence was visible in the crater and incandescent blocks rolled a few meters down the volcano's NW flank. Sources: Washington Volcanic Ash Advisory Center (VAAC), El Universo, Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Veniaminof (United States) | 21 April-27 April 2004 | Continuing ActivityCite this Report
Veniaminof Aleutian Ridge Volcanic Arc	After a period of heightened seismicity at Veniaminof during 14-17 April that led AVO to increase the Concern Color Code from Green to Yellow, there was a marked decrease in the episodes of low-level volcanic tremor and small volcanic earthquakes through 26 April. A newly installed internet-based video camera located in Perryville allowed AVO to observe the volcano during clear weather. During the afternoon and evening of 25 April, more than 25 small steam-and-ash emissions were seen during an 8-hour period, producing clouds that rose 300-600 m above the active cone. These clouds typically were confined to the summit caldera, but could pose a hazard to people and low-flying aircraft in the immediate vicinity of the active cone. Through 26 April, Veniaminof remained at Concern Color 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 21,447 individual reports over 1,277 weeks (average of 17 per week) on 339 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)