All times are local unless otherwise stated.

Cleveland (United States) | 18 April-24 April 2012 | New Activity / Unrest Cite this Report
Cleveland Aleutian Ridge Volcanic Arc	AVO reported that elevated surface temperatures were observed over Cleveland in satellite imagery during 17-18 April. An explosion on 19 April at 0438, detected by seismometers at Makushin and Okmok volcanoes, generated an ash cloud the rose 4-6 km (13,100-19,700 ft) a.s.l. and drifted S. Satellite images showed block-and-ash deposits extending for up to 1 km down the S flank. A possible weak thermal anomaly was detected in images during 20-21 April. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Lamongan (Indonesia) | 18 April-24 April 2012 | New Activity / Unrest Cite this Report
Lamongan Sunda Volcanic Arc	CVGHM reported that, although weather conditions often prevented observations of Lamongan during 9 March-17 April, white plumes were occasionally seen rising 10-20 m above the crater rim. Seismicity decreased during this period. CVGHM lowered the Alert Level to 1 (on a scale of 1-4) on 19 April. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Lokon-Empung (Indonesia) | 18 April-24 April 2012 | New Activity / Unrest Cite this Report
Lokon-Empung Sangihe Volcanic Arc	CVGHM reported that during the morning on 24 April diffuse white plumes rose 25-50 m above Tompaluan crater, in the saddle between the Lokon-Empung peaks. Later that day an eruption was accompanied by loud "thumping" noises heard at local observation posts, though fog prevented views of the crater. The next day diffuse white plumes rose 50-100 m above the crater. The Alert Level remained at 3 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Popocatepetl (Mexico) | 18 April-24 April 2012 | New Activity / Unrest Cite this Report
Popocatepetl Trans-Mexican Volcanic Belt	CENAPRED reported that multiple gas-and-ash plumes rose from Popocatépetl on 18 April; one of the emissions was accompanied by increased incandescence in the crater. An explosion ejected incandescent fragments that landed on the N and NE flanks as far as 800 m from the crater. The fragments landed on snow and generated small lahars. A dense gas, steam, and ash plume drifted E and SE. On 19 April gas-and-ash plumes rose above the crater and drifted ESE, and incandescent fragments rolled 1 km down the flanks. The next day an episode of spasmodic tremor was accompanied by a dense plume of gas, water vapor, and ash that rose 1.5 km and drifted E. During 21-23 April gas-and-steam emissions that sometimes contained small amounts of ash drifted SE, E, and SW. Seismicity was low during 21-22 April and again increased on 23 April. That same day an ash plume drifted NE and incandescent fragments were ejected W. The Alert Level remained at Yellow Phase Three. Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Etna (Italy) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Etna Sicily Volcanic Province	Sezione di Catania - Osservatorio Etneo reported that the twenty-fifth paroxysmal eruptive episode since January 2011 took place at New SE Crater (New SEC) of Etna during the morning of 24 April following about 11 days of quiescence. The episode was characterized by lava fountains, emissions of ash and lapilli, and lava flows that descended the Valle del Bove. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Karymsky (Russia) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka Volcanic Arc	KVERT reported that moderate seismic activity from Karymsky continued to be detected during 13-20 April. Satellite imagery showed a thermal anomaly on the volcano during 15-19 April. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kilauea (United States) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 18-24 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.1 km from the coast. During 19-20 April small lava flows issued from a vent on the SE edge of the Pu'u 'O'o crater floor. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Nevado del Ruiz (Colombia) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Nevado del Ruiz Northern Andean Volcanic Arc	According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 18-19 April multiple seismic signals recorded at Nevado del Ruiz possibly indicated ash emissions, but they could not be verified due to weather conditions. Video data and observers in the city of Manizales (25 km NW) indicated that gas-and-steam plumes rose 900 m above the crater and drifted SE during the morning on 18 April. Satellite imagery detected a steam and sulfur dioxide plume the next day. During 20-24 April high levels of sulfur dioxide were detected in satellite images. Gas-and-steam plumes rose 1-2 km above the crater. The Alert Level remained at II (Orange; "eruption likely within days or weeks"). Source: Servicio Geológico Colombiano (SGC)
Puyehue-Cordon Caulle (Chile) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Puyehue-Cordon Caulle Southern Andean Volcanic Arc	OVDAS-SERNAGEOMIN reported that, although cloud cover often prevented observations during 17-22 April, satellite and web camera views of the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, occasionally showed plumes that rose no higher than 400 m above the crater. Incandescence from the crater was observed during 17-18 and 20-21 April. Due to the low level of activity and decreasing seismicity, the Alert Level was lowered to Yellow on 23 April. Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Reventador (Ecuador) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Reventador Northern Andean Volcanic Arc	IG reported that on 18 April a plume with low ash content rose 2 km above Reventador's crater and drifted NW. A steam plume rose 100 m above the crater the next day. Weather conditions prevented observations during 20-23 April. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Santa Maria (Guatemala) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Santa Maria Central America Volcanic Arc	INSIVUMEH reported that during 22-24 April explosions from Santa María's Santiaguito lava-dome complex generated ash plumes that rose 900 m above the crater and drifted SE. Ash possibly fell in Santa María de Jesus and Calahuache. Sources: Washington Volcanic Ash Advisory Center (VAAC), Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch (Russia) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that explosive activity at Shiveluch continued during 13-20 April. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption and was accompanied by fumarolic activity. Observers reported that ash plumes rose to altitudes of 6.5-7.5 km (21,300-24,600 ft) a.s.l. during 16-17 April and to altitudes of 4-5 km (13,100-16,400 ft) a.s.l. on the other days. Satellite imagery showed a weak thermal anomaly daily on the lava dome, and ash plumes that drifted 120 km N, NE, and E during 14-15 and 17-18 April. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Tungurahua (Ecuador) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Tungurahua Northern Andean Volcanic Arc	IG reported that on 18 April a plume with low ash content rose 2 km above Tungurahua and drifted NW. Ashfall was reported in Juive (7 km NNW) and Cusúa (7 km NW). The next day, steam rose 1 km above the crater and drifted W, and lahars descended the W and SW flanks. On 20 April steam plumes rose 500-800 m and drifted W. A moderate-sized explosion on 22 April produced "cannon shots" and sounds resembling blocks rolling down the flanks. Rice-sized tephra fell in Pillate (7 km W). Lahars descended the Choglontus (SW), Confesionario (WSW), Romero Ingapirca, and Chontapamba (W) drainages, causing the Baños-Penipe road to close near Chontapamba. On 24 April a steam-and-ash plume rose 2 km above the crater. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Villarrica (Chile) | 18 April-24 April 2012 | Continuing ActivityCite this Report
Villarrica Southern Andean Volcanic Arc	According to Projecto Observación Visual Volcán Villarrica (POVI), an ash plume rose 50 m above Villarrica on 19 April. Source: Proyecto Observación Villarrica Internet (POVI)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,652 individual reports over 1,244 weeks (average of 17 per week) on 338 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)