All times are local unless otherwise stated.

Masaya | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Masaya Nicaragua	INETER reported that at 1655 on 21 July a small explosion at Masaya’s Santiago Crater produced a gas-and-ash plume that drifted NW and W. A thin layer of ash was deposited near the volcano and in surrounding communities downwind, including San Ignacio, Panamá, and Arenal. During field visits during 21-22 July, INETER volcanologists confirmed that the emissions had originated from a vent on the crater floor. Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Piton de la Fournaise | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Piton de la Fournaise Reunion Island (France)	OVPF reported that a seismic crisis at Piton de la Fournaise began at 0513 on 29 July and was accompanied by rapid deformation. Tremor beneath the N flank began to be recorded around 1200, indicating the likely start of the eruption, though inclement weather conditions prevented visual confirmation. OVPF visited the site and conducted helicopter overflights around 1630 and observed three active fissures, with a total length of 450 m, that crossed the July 2018 flows on the NW flank (600 m from the Formica Léo). The fissures produced 20-30-m-high lava fountains and ‘a’a lava flows that traveled no more than 500 m. After a gradual decline, volcanic tremor ceased at 0430 on 30 July signaling the end of the eruption. Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Semisopochnoi | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Semisopochnoi Aleutian Islands (USA)	On 24 July AVO reported that satellite data from the previous week indicated that the 100-m-wide crater lake in the N cone of Semisopochnoi’s Cerberus three-cone cluster was gone, and a new shallow inner crater about 80 m in diameter had formed on the crater floor. The lake had persisted since January 2019. Seismicity during 25-30 July was characterized by periods of continuous tremor, low-frequency earthquakes, and small explosion signals. Small steam plumes were visible in periodic, cloud-free satellite images, along with minor sulfur dioxide emissions. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Shishaldin | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Shishaldin Fox Islands (USA)	On 23 July field crews observed minor spattering and surface lava flows in Shishaldin’s summit crater during an overflight, prompting AVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch. Elevated surface temperatures were observed in multiple satellite images during 24-30 July, though views were sometimes obscured by weather clouds. Nearly continuous weak seismic tremor was detected, and occasional infrasound signals consistent with small Strombolian explosions were recorded during 26-27 July. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Tangkuban Parahu | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Tangkuban Parahu Western Java	PVMBG reported that a phreatic eruption at Tangkubanparahu's Ratu Crater began at 1548 on 26 July and was recorded in seismic data for about five minutes and 30 seconds. Dense blackish-gray, sediment-laden plumes rose around 200 m above the lake surface, and a lighter-colored component containing fine ash rose 600 m and spread NE and S. Tephra fell in a concentrated area within 500 m of the vent, creating deposits 5-7 cm thick. Visitors to the Kawasan Wisata Gunung Tangkuban Parahu tourist area that borders a section of the E and SE crater rim immediately evacuated. BNPB reported that the local government closed the tourist area noting that ash fell within a 1-2 km radius, in Jayagiri Village, Lembang District, and areas of the West Bandung Regency. Activity decreased after the eruption; tremor amplitude decreased during 27-28 July, and diffuse white plumes rose from the vent. PVMBG noted that during the previous month white plumes of variable density rose as high as 150 m above the crater floor. Small local inflation was recorded, and deformation data continued to indicate instability at least through 27 July. Hydrogen sulfide and sulfur dioxide concentrations began to increase on 10 July and then significantly declined at 1200 on 13 July. Measurements on 21 July indicated that gas emissions continued to fluctuate but decreased overall. The Alert Level remained at 1 (on a scale of 1-4). Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Badan Nacional Penanggulangan Bencana (BNPB)
Ubinas | 24 July-30 July 2019 | New Activity / Unrest Cite this Report
Ubinas Peru	IGP reported that activity at Ubinas continued to be elevated after the 19 July explosions. A total of 1,522 earthquakes, all with magnitudes under 2.2, were recorded during 20-24 July. Explosions were detected at 0718 and 2325 on 22 July. The Buenos Aires VAAC reported that an ash plume rising to 9.4 km (31,000 ft) a.s.l. and drifting SE was identified in satellite data at 0040 on 22 July. Continuous steam-and-gas emissions with sporadic pulses of ash were visible in webcam views during the rest of the day. Ash emissions near the summit crater were periodically visible on 24 July though often partially hidden by weather clouds. Ash plumes were visible in satellite images rising to 7 km (23,000 ft) a.s.l. Diffuse ash emissions near the crater were visible on 25 July, though a thermal anomaly was identified in satellite images. During 26-28 July there were 503 people evacuated from areas affected by ashfall. Sources: Instituto Geofísico del Perú (IGP), Buenos Aires Volcanic Ash Advisory Center (VAAC), Gobierno Regional de Moquegua

Aira | 24 July-30 July 2019 | Continuing ActivityCite this Report
Aira Kyushu (Japan)	JMA reported that on 22 July an explosion at Minamidake crater (at Aira Caldera’s Sakurajima volcano) generated an ash plume that rose to 1.5 km above the crater rim. At 1725 and 1754 on 28 July ash plumes rose 3.5-3.8 km above the crater rim and causing ashfall in areas N of the crater including Kirishima (20 km NE), Shimizu Town, and parts of the Kumamoto Prefecture. The Alert Level remained at 3 (on a 5-level scale). Source: Japan Meteorological Agency (JMA)
Asosan | 24 July-30 July 2019 | Continuing ActivityCite this Report
Asosan Kyushu (Japan)	JMA reported that at 0757 on 26 July a small eruption at Asosan’s Nakadake Crater generated grayish-white ash plumes that rose 1.6 km above the crater rim and drifted NW. Webcam images showed incandescent material in the vent. Minor ashfall was reported in areas downwind including Minamioguni-cho (Kumamoto Prefecture, N) and Kuze-cho (Oita Prefecture, NE). Plumes continued to be emitted during 0900-1300, rising to 400 m. Activity increased at 0442 on 28 July and remained elevated at least through 1500 on 29 July. Grayish-white plumes rose as high as 1.2 km above the crater rim and drifted NE and N. Sulfur dioxide emissions were very high on 29 July, at 4,300 tons per day. The Alert Level remained at 2 (on a scale of 1-5). Source: Japan Meteorological Agency (JMA)
Dukono | 24 July-30 July 2019 | Continuing ActivityCite this Report
Dukono Halmahera	Based on satellite and wind model data, and notices from PVMBG, the Darwin VAAC reported that during 24-30 July ash plumes from Dukono rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted mainly W, N, NE, and E. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone. Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Ebeko | 24 July-30 July 2019 | Continuing ActivityCite this Report
Ebeko Paramushir Island (Russia)	Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 20-26 July that sent ash plumes up to 4 km (13,100 ft) a.s.l. The plumes drifted in multiple directions. A thermal anomaly was visible in satellite images on 18, 20, and 25 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Karymsky | 24 July-30 July 2019 | Continuing ActivityCite this Report
Karymsky Eastern Kamchatka (Russia)	KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 18-19 and 25 July. An ash plume drifted 134 km SE on 25 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Klyuchevskoy | 24 July-30 July 2019 | Continuing ActivityCite this Report
Klyuchevskoy Central Kamchatka (Russia)	KVERT reported that a weak thermal anomaly over Klyuchevskoy was visible in satellite images during 18-19 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Merapi | 24 July-30 July 2019 | Continuing ActivityCite this Report
Merapi Central Java	PVMBG reported that during 22-28 July the lava-dome volume at Merapi did not change and was an estimated 475,000 cubic meters, based on analyses of drone images. Extruded lava fell into the upper parts of the SE-flank, generating two block-and-ash flows that traveled 1,000 m and 950 m down the Gendol drainage on 24 and 27 July, respectively. Diffuse white plumes rose as high as 50 m above the summit on some days. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to remain outside of the 3-km exclusion zone. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Nevado del Ruiz | 24 July-30 July 2019 | Continuing ActivityCite this Report
Nevado del Ruiz Colombia	Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 23-30 July small plumes of gas and ash rose from Nevado del Ruiz based on webcam images. A weak thermal anomaly was identified in satellite data. The Alert Level remained at 3 (Yellow; the second lowest level on a four-color scale). Source: Servicio Geológico Colombiano (SGC)
Sangeang Api | 24 July-30 July 2019 | Continuing ActivityCite this Report
Sangeang Api N of Sumbawa Island	The Darwin VAAC reported that during 24-30 July multiple ash plumes from Sangeang Api were identified by pilots and in satellite images rising to 2.4-3 km (8,000-10,000 ft) a.s.l. and quickly dissipating N, NW, W, and SW. The Alert Level remained at 2 (on a scale of 1-4). Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Sheveluch | 24 July-30 July 2019 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 19-26 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Tengger Caldera | 24 July-30 July 2019 | Continuing ActivityCite this Report
Tengger Caldera Eastern Java	The Darwin VAAC reported that on 28 July ash plumes from Tengger Caldera’s Bromo cone rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NW based on webcam images, satellite data, and weather models. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to stay outside of a 1-km radius of the crater. Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Turrialba | 24 July-30 July 2019 | Continuing ActivityCite this Report
Turrialba Costa Rica	OVSICORI-UNA reported that an eruptive event at Turrialba was detected at 1441 on 28 July, though inclement weather conditions prevented visual confirmation. Ashfall was reported in La Picada (N) and El Retiro farms. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Villarrica | 24 July-30 July 2019 | Continuing ActivityCite this Report
Villarrica Central Chile	POVI reported that during 24-25 July multiple Strombolian explosions in Villarrica’s summit crater were detected in seismic data and ejected incandescent material onto the flanks. Source: Proyecto Observación Villarrica Internet (POVI)

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.

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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)