All times are local unless otherwise stated.

Galeras (Colombia) | 28 July-3 August 2004 | New Activity / Unrest Cite this Report
Galeras Northern Andean Volcanic Arc	Satellite imagery showed a faint ash plume emitted from Galeras on 29 July around 0745. The height and direction of the plume was unknown. Source: Washington Volcanic Ash Advisory Center (VAAC)
Lewotolok (Indonesia) | 28 July-3 August 2004 | New Activity / Unrest Cite this Report
Lewotolok Sunda Volcanic Arc	DVGHM stated that the pilot report of a plume emitted from Lewotolo on 25 June was false. Further investigation revealed that the emission was actually from Egon. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Nightingale Island (United Kingdom) | 28 July-3 August 2004 | New Activity / Unrest Cite this Report
Nightingale Island Southern Atlantic Volcano Group	According to a news report, a swarm of earthquakes occurred beneath Tristan da Cunha during the nights of 28 and 29 July. A scientist monitoring seismic activity from the Preparatory Commission for the Comprehensive Nuclear Test-Ban Treaty Organization, Vienna International Centre indicated that the main swarm lasted ~8 hours and occurred ~30 km below the volcano. After the swarm, there were a few individual earthquakes and then activity tapered off. Source: Tristan Times
Spurr (United States) | 28 July-3 August 2004 | New Activity / Unrest Cite this Report
Spurr Alaska Peninsula Volcanic Arc	According to AVO during 22-30 July elevated levels of seismicity continued to be recorded at Spurr, with approximately 10-20 earthquakes occurring daily beneath the summit. The level of activity had remained constant for the previous several weeks. Although this represented a notable increase over background seismicity levels, there was no indication that an eruption was imminent. AVO noted that this type of seismicity often will decline without producing an eruption. Spurr remained at Concern Color Code Yellow. Sources: US Geological Survey Alaska Volcano Observatory (AVO), Reuters, Associated Press

Anatahan (United States) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Anatahan Mariana Volcanic Arc	During 26 July to 3 August, seismicity at Anatahan remained at very low levels. Interpretations of seismic data suggested that the frequent explosions during the previous week had decreased. Ash plumes probably did not rise higher than 6 km above the volcano. Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
Colima (Mexico) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Colima Trans-Mexican Volcanic Arc	According to Universidad de Colima, during 27 July to 2 August an average of three ash-containing emissions occurred at Colima daily. The emissions did not rise higher than 3 km above the crater and mainly drifted W. The Washington VAAC reported that ash plumes were visible on satellite imagery during several days. Sources: Washington Volcanic Ash Advisory Center (VAAC), Centro Universitario de Estudios Vulcanológicos (CUEV) - Universidad de Colima
Kerinci (Indonesia) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Kerinci Sunda Volcanic Arc	During 24-31 July, volcanic and seismic activity increased at Kerinci. An ash plume rose 100-600 m above the crater rim and drifted W. Ash was deposited up to 1 cm thick and as far away as 3 km from the crater. There was an increase in volcanic earthquakes during the report week in comparison to the previous week. Visitors were advised not to climb to the volcano's peak until activity decreased. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Kilauea (United States) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	An episode of deformation consisting of deflation, inflation, then deflation began at Kilauea on the morning of 27 July. It was accompanied by increased surface activity at several places. During inflation, seismicity greatly increased below Kilauea's caldera. Field observers reported that deformation may have occurred at the S flank of Pu`u `O`o. Several surface lava flows were visible on the coastal flat during 28 July to 2 August, and lava continued to flow into the sea. Aside from the deflation-inflation-deflation event, seismicity was weak beneath Kilauea's summit and tremor at Pu`u `O`o was at moderate-to-high levels. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Sheveluch (Russia) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	Seismicity was above background levels at Shiveluch during 22-30 July, with weak earthquakes occurring 0-5 km below the active lava dome. Gas-and-steam plumes rose to ~2.8 km a.s.l. on 28 and 29 July. Shiveluch remained at Concern Color Code Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Shishaldin (United States) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Shishaldin Aleutian Ridge Volcanic Arc	Low-level seismic tremor continued at Shishaldin during 22-30 July as it had for several months. On 24 July an AVO field crew observed vigorous steaming at the summit and what may have been ash deposits on the volcano's upper slopes. Shishaldin remained at Concern Color Code Yellow. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Soufriere Hills (United Kingdom) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Soufriere Hills Lesser Antilles Volcanic Arc	Volcanic and seismic activity remained at low levels at Soufrière Hills during 23-30 July. The seismic network recorded two hybrid earthquakes and eight rockfalls. The sulfur-dioxide flux ranged between 175 and 300 metric tons per day, which is lower than the long-term eruption average of ~500 metric tons per day. Source: Montserrat Volcano Observatory (MVO)
Tungurahua (Ecuador) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Tungurahua Northern Andean Volcanic Arc	Volcanic and seismic activity remained at relatively low levels at Tungurahua during 28 July to 2 August, with emissions of gas, steam, and small amounts of ash rising to ~500 m above the volcano. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC)
Veniaminof (United States) | 28 July-3 August 2004 | Continuing ActivityCite this Report
Veniaminof Aleutian Ridge Volcanic Arc	Episodes of volcanic tremor continued intermittently at Veniaminof during 22-30 July. No visual observations of ash emissions were made after 22 July, although the recorded seismicity was similar to that observed during ash emissions in the previous few months. Most such emissions did not reach 3 km a.s.l., though a few reportedly reached as high as 3.7 km. 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 21,279 individual reports over 1,270 weeks (average of 17 per week) on 340 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)