All times are local unless otherwise stated.

Piton de la Fournaise | 28 April-4 May 2004 | New Activity / Unrest Cite this Report
Piton de la Fournaise Reunion Island (France)	A new seismic event began at Piton de la Fournaise on 2 May at 1903, following one month of relatively high seismic activity at the volcano (with 10-30 earthquakes per day and two minor seismic crises) and continuous inflation at the summit. At 1936, eruption tremor began. The high intensity of tremor near Bory crater indicated that an eruption probably started within or very close to the crater. The Toulouse VAAC warned aircraft to be cautious in the airspace near the volcano. Sources: Toulouse Volcanic Ash Advisory Centre (VAAC), Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Shishaldin | 28 April-4 May 2004 | New Activity / Unrest Cite this Report
Shishaldin Fox Islands (USA)	AVO raised the Concern Color Code at Shishaldin from Green to Yellow on 3 May due to unusual seismic activity at Shishaldin during the previous week. Seismicity changed at the volcano from discrete earthquakes to more continuous ones. Tremor was observed for the first time since the most recent eruption ended in May 1999. Airwaves (acoustical waves traveling in air) accompanying earthquakes were recorded by the seismic network, suggesting that the source of seismicity had become more shallow. AVO reported that there were no indications that an eruption was imminent or even likely. Satellite data showed no significant increase in ground temperature at the volcano, nor had there been reports of increased steaming. However, AVO warned that activity at Shishaldin could increase rapidly and increased the frequency of their seismic-data analysis. Source: US Geological Survey Alaska Volcano Observatory (AVO)

Aira | 28 April-4 May 2004 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	Based on information from JMA, the Tokyo VAAC reported that an eruption at Sakura-jima on 28 April at 1820 produced a plume to a height of ~2.4 km a.s.l. that drifted SE. No ash was visible on satellite imagery. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Anatahan | 28 April-4 May 2004 | Continuing ActivityCite this Report
Anatahan Mariana Islands (USA)	Early on 28 April, the level of seismicity at Anatahan increased to its highest level since renewed seismic activity began on 24 April. At this time the lava dome probably increased in size. Seismicity decreased somewhat during the following ~5 days, but M 2-2.5 earthquakes and small explosions still occurred about every minute, and steam-and-ash emissions still rose several hundred meters above the volcano. Local authorities placed Anatahan Island off-limits until further notice. They also concluded that although the volcano was not currently dangerous to most aircraft within the Mariana Islands airspace, conditions could change rapidly and aircraft should pass upwind of Anatahan or more than 30 km downwind from the island and exercise due caution within 30-50 km of the volcano. Sources: Associated Press, Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
Bagana | 28 April-4 May 2004 | Continuing ActivityCite this Report
Bagana Bougainville (Papua New Guinea)	According to a news article, following the emission of new lava from Bagana on 27 April, local volcanologists and a team of provincial disaster delegates conducted an aerial inspection of the area around the volcano on 2 May. The team concluded that the lava flows were not an immediate threat to the safety of villagers near the volcano. A spokesperson for Papua New Guinea's national Disaster Center reportedly said, "the aerial inspection team noted a continual effusion of lava flowing in a south-westerly direction but there is a lot of vegetation in the area which is acting as a buffer." Sources: Australian Associated Press, Reuters
Dukono | 28 April-4 May 2004 | Continuing ActivityCite this Report
Dukono Halmahera	During 28 April to 4 May, 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 | 28 April-4 May 2004 | Continuing ActivityCite this Report
Fuego South-Central Guatemala	During 28 April to 4 May, explosions at Fuego produced gas-and-ash clouds. On 28 April, an explosion produced an ash plume to ~1.5 km above the volcano, and ash was deposited ~4 km SW of the volcano in the villages of Panimaché I and Panimaché II. In addition, a small avalanche of volcanic material traveled W toward Santa Teresa Ravine. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Kilauea | 28 April-4 May 2004 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 28 April to 4 May, lava from Kilauea continued to flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. On 2 May, lava from the recently named Banana flow began pouring over Paliuli and advanced onto the coastal flat. By 4 May the lava-flow front was ~1 km from the ocean, the closest proximity to the coast since the fall of 2003. During the report period, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Sangay | 28 April-4 May 2004 | Continuing ActivityCite this Report
Sangay Ecuador	Based on a pilots report, the Washington VAAC reported that ash from an eruption at Sangay produced a plume to a height of ~6 km a.s.l. on 1 May at 1750. Ash was not visible on satellite imagery. Source: Washington Volcanic Ash Advisory Center (VAAC)
Santa Maria | 28 April-4 May 2004 | Continuing ActivityCite this Report
Santa Maria Southwestern Guatemala	During 28 April to 4 May, weak-to-moderate explosions at Santa María's Santiaguito lava-dome complex produced gas-and-ash plumes that rose to ~1 km above the crater. Small partial collapses at the edge of the Caliente lava dome produced avalanches of incandescent volcanic material to the SW. An explosion on 27 April produced a pyroclastic flow that traveled ~3 km to the SW. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Soufriere Hills | 28 April-4 May 2004 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	Volcanic activity at Soufrière Hills was at low levels during 23-30 April. Seismicity included low-level tremor, spasmodic tremor, and small numbers of long-period and hybrid earthquakes. A large hybrid earthquake on 29 April at 1540 resulted in a small amount of ash venting from the summit. The sulfur-dioxide flux was low throughout the report period. Source: Montserrat Volcano Observatory (MVO)
Suwanosejima | 28 April-4 May 2004 | Continuing ActivityCite this Report
Suwanosejima Ryukyu Islands (Japan)	According to the Tokyo VAAC, ash emitted from Suwanose-jima was reported on 28 April at a height of ~3 km a.s.l. extending SE. No ash was visible on satellite imagery. JMA reported that an explosion occurred on 1 May at 0906, but it was not known if an ash cloud was produced. Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Tungurahua | 28 April-4 May 2004 | Continuing ActivityCite this Report
Tungurahua Ecuador	During 27 April to 4 May, emissions of gas and ash continued at Tungurahua. Volcano-tectonic earthquakes on 27 and 28 April preceded a slight increase in the number of sudden explosions at Tungurahua on 30 April. According to a news article, on 1 and 2 May ash fell in the towns of Cotaló and San Juan (W of the volcano). The level of seismicity at Tungurahua decreased on 4 May. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), El Universo, Washington Volcanic Ash Advisory Center (VAAC)
Veniaminof | 28 April-4 May 2004 | Continuing ActivityCite this Report
Veniaminof Alaska Peninsula, Alaska	Unrest at Veniaminof during 23-30 April was characterized by small intermittent ash emissions, low-level volcanic tremor, and small volcanic earthquakes. Small ash emissions were observed during clear weather on 25 and 28 April rising to ~1 km above the active cone. Seismic activity fluctuated, but remained above background levels. There were no indications that more vigorous activity was imminent. 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 19,996 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)