All times are local unless otherwise stated.

Llaima | 9 April-15 April 2003 | New Activity / UnrestCite this Report

Llaima Central Chile

Increased seismic and volcanic activity at Llaima during 9-11 April led officials to put the volcano at Alert Level Yellow. Seismic signals indicating weak eruptive activity were recorded and observations made during a flight revealed a thin layer of pyroclastic material atop a glacier on the NE flank. In addition to extensive fumarolic activity, observers saw new cracks in the glacier. Only weak fumaroles were seen during 12-13 April. Sources: Diario El Sur, El Diario Austral de Los Rios

Kilauea | 9 April-15 April 2003 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	Lava continued to enter the ocean at the West Highcastle entry at Kilauea during 10-14 April. Surface lava flows were visible on the Kohala flow and the easternmost stream of the Mother's Day flow. Generally, seismicity remained at normal levels, with a swarm of long-period earthquakes and tremor continuing to occur. Volcanic tremor was recorded at Pu`u `O`o for more than a week and there were small deformation events at Kilauea's summit and at Pu`u `O`o. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Klyuchevskoy | 9 April-15 April 2003 | Continuing ActivityCite this Report
Klyuchevskoy Central Kamchatka (Russia)	Seismicity was above background levels at Kliuchevskoi during 4-11 April, with 10-15 earthquakes occurring per day at depths of ~30 km. Continuous spasmodic volcanic tremor and a large number of weak shallow earthquakes were recorded. Gas-and-steam plumes rose to low levels above the crater and fumarolic activity was observed on 7 April. The Concern Color Code remained at Yellow. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Lokon-Empung | 9 April-15 April 2003 | Continuing ActivityCite this Report
Lokon-Empung Sulawesi	After an explosion on 1 April at Lokon-Empung, volcanic activity decreased through 6 April. A "white-thick ash plume" rose to low levels and there were no observations of ash explosions. Seismicity after the 1 April explosion was dominated by tremor due to the release of gases. Lokon-Empung remained at Alert Level 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Popocatepetl | 9 April-15 April 2003 | Continuing ActivityCite this Report
Popocatepetl Mexico	During 9-15 April, moderate emissions of mainly gas and steam occurred at Popocatépetl. In addition, isolated episodes of low-amplitude harmonic tremor were occasionally recorded. There were still remains of the lava dome in Popocatépetl's crater. Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Semeru | 9 April-15 April 2003 | Continuing ActivityCite this Report
Semeru Eastern Java	Volcanic activity remained at relatively high levels at Semeru during 31 March to 6 April. "White-gray ash plumes" rose 400-600 m above the summit and seismicity was dominated by 738 explosion events. According to the Darwin VAAC, a pilot reported seeing ash ~2.5 km above Semeru on 15 April at 1038. No ash was visible on satellite imagery. The Alert Level at Semeru remained at 2 (on a scale of 1-4). Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Sheveluch | 9 April-15 April 2003 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	Seismicity at Shiveluch remained above background levels during 4-11 April. Seismic data indicated that 8 ash-and-gas explosions reached heights up to 3 km above the lava dome and hot avalanches possibly occurred. Weak shallow earthquakes and intermittent spasmodic volcanic tremor were recorded. Gas-and-steam plumes rose to low levels above the dome. A thermal anomaly was visible on satellite imagery. Shiveluch remained at Concern Color Code Yellow. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Soufriere Hills | 9 April-15 April 2003 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	Activity at Soufrière Hills was generally at moderate levels during 4-11 April, although there were short periods of more elevated activity. Rockfalls and pyroclastic flows mainly occurred on the E side of the lava dome in the Tar River Valley. Pyroclastic flows were also observed on the NE flank in White's and Tuitt's ghauts. Torrential rainfall late in the evening of 10 April produced mudflows in the Belham River and triggered pyroclastic flows on the E, N, and NW flanks of the lava dome. The Washington VAAC reported that low-level ash plumes were sometimes visible on satellite imagery. Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)
Stromboli | 9 April-15 April 2003 | Continuing ActivityCite this Report
Stromboli Aeolian Islands (Italy)	INGV-CT reported that the effusive eruption at Stromboli, which started on 28 December 2002, continued through 8 April 2003 from vents at 600 m a.s.l. On 5 April scientists from INGV-CT observing the volcano from a helicopter saw lava flowing from three vents at 600 m and a diluted gas plume emanating from the summit craters. A few minutes after the survey began the gas plume suddenly became red and soon after juvenile, darker material was emitted from Crater 1 (the NE crater). A hot, cauliflower-shaped jet rapidly grew above the crater. Around 2-3 seconds later Crater 3 (the SW crater) emitted a hot jet of juvenile material and soon after the two jets joined together. Then a very powerful explosion occurred at 0912 that pushed the helicopter away from the crater. A mushroom-shaped dark cloud rose to ~1 km above Stromboli's summit. The base of the cloud was surrounded by a dark gray cloud similar to a base surge. Bombs, blocks, and ash fell on the volcano's NE flank above 400 m elevation, burning vegetation. Most ejecta drifted W, falling on the town of Ginostra, about 1.5 km away, and destroyed two houses. Observations after the eruption revealed that the lava-flow field on the upper Sciara del Fuoco (a horseshoe-shaped scarp) at 600 m elevation was completely covered by a carpet of brown debris ejected from Crater 1 during the initial phase of the event. A thick steam cloud rose above the debris carpet, formed by vaporization of wet debris above the hot lava flows. Alternating pulses of black and red ash emissions rose mainly above Crater 3. The upper part of the volcano (above 700 m elevation) was completely covered by a continuous carpet of pyroclastic products. Within a few minutes after the eruption, lava flows were active again on the Sciara del Fuoco at 600 m elevation, emerging through the debris carpet. On 8 April INGV-CT scientists saw lava flowing from four vents on the Sciara del Fuoco. Two flows traveled in the middle of the scarp and blocks detaching from the lava-flow fronts generated small rockfalls that reached the sea. News about the eruption (in Italian) and photos are available on the INGV-CT website. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Tungurahua | 9 April-15 April 2003 | Continuing ActivityCite this Report
Tungurahua Ecuador	Activity at Tungurahua during 9-14 April was relatively low, with sporadic explosions. The largest reported explosion occurred on 10 April and produced a plume with low ash content to ~2 km above the volcano. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
Ulawun | 9 April-15 April 2003 | Continuing ActivityCite this Report
Ulawun New Britain (Papua New Guinea)	The Darwin VAAC reported that a possible low-level ash plume was visible on satellite imagery on 14 April. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Veniaminof | 9 April-15 April 2003 | Continuing ActivityCite this Report
Veniaminof Alaska Peninsula, Alaska	Seismic activity remained at very low levels at Veniaminof during 4-11 April. Tremor was almost completely absent, and only a few low-frequency events were recorded. Satellite images during the week did not reveal any elevated surface temperatures, ash emissions, or ash deposits at the volcano. Due to the decline in seismicity, AVO lowered the Concern Color Code for Veniaminof from Yellow to Green. AVO stated that while Veniaminof is in its current state of activity, low-level steaming and minor ash emissions may periodically occur. Source: US Geological Survey Alaska Volcano Observatory (AVO)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 18,995 individual reports over 1,169 weeks (average of 16 per week) on 329 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.

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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.

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 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)