All times are local unless otherwise stated.

Katla (Iceland) | 26 July-1 August 2017 | New Activity / Unrest Cite this Report
Katla Iceland Neovolcanic Rift Volcanic Province	On 29 July the Iceland Met Office (IMO) reported that a glacial outburst flood (jökulhlaup) in the Múlakvísl river, SE of Katla, had begun, and a M 3 earthquake along with a few smaller earthquakes were located in the N part of the caldera. Nearby seismic stations detected tremor possibly linked to the flood, though a subglacial volcanic component was not ruled out. The Aviation Color Code was raised to Yellow, the second lowest level on a four-color scale. The public was advised to stay away from the river; it was dark colored and had a sulfur odor. By 31 July the jökulhlaup had subsided with conductivity measurements and tremor slowly reaching normal levels. The Aviation Color Code was lowered to Green. Source: Icelandic Meteorological Office (IMO)
Moyorodake [Medvezhia] (Japan - administered by Russia) | 26 July-1 August 2017 | New Activity / Unrest Cite this Report
Moyorodake [Medvezhia] Kuril Volcanic Arc	The Institute of Volcanology and Geodynamics (Russian Academy of Natural Science) reported that during the morning of 31 July volcanologists working on Kudryavy, a stratovolcano of the Medvezhia volcanic complex, noted a sharp increase in the volume of vapor-and-gas emissions, with a plume rising more than 1 km. The emissions rose from a new crater, Malysh, that was formed after the 1999 phreatic eruption. A significant increase in temperature (an average of 100 degrees Celsius) was measured at fumarolic sites, and new high-temperature areas were noted. Crusts of native sulfur at the boundaries of high-temperature areas were melting and burning. Two people at the top of the volcano and workers at the main base camp (3.5 km S) self-evacuated. The report noted that a M 5.7 earthquake had occurred at 0800 that same morning, 200 km NE, within the same system of tectonic faults that the volcano resides on. The volcano has a permeable system of fissures, through which there has been constant degassing for more than 130 years. Source: Institute of Volcanology and Geodynamics, Russian Academy of Natural Science
Piton de la Fournaise (France) | 26 July-1 August 2017 | New Activity / Unrest Cite this Report
Piton de la Fournaise Reunion Hotspot Volcano Group	OVPF reported that the eruption at Piton de la Fournaise that began on 14 July continued through 1 August, though weather conditions often prevented visual observations. Tremor levels fluctuated. A few estimates based on satellite data indicated a minimum flow rate of 1-2 cubic meters per second. During the early evening on 25 July two vents in the main cone were active, and lava frequently overflowed parts of the channel. Visual observations on 30 July revealed that the lava-flow terminus remained 2.8 km from the vents. Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Sangay (Ecuador) | 26 July-1 August 2017 | New Activity / Unrest Cite this Report
Sangay Northern Andean Volcanic Arc	Based on information from the Guayaquil MWO, the Washington VAAC reported that on 1 August an emission from Sangay rose to an altitude of 5.3 km (17,500 ft) a.s.l. and drifted W. Source: Washington Volcanic Ash Advisory Center (VAAC)
Sangeang Api (Indonesia) | 26 July-1 August 2017 | New Activity / Unrest Cite this Report
Sangeang Api Sunda Volcanic Arc	Based on analyses of satellite imagery, pilot observations, and wind data, the Darwin VAAC reported that during 29-30 July ash plumes from Sangeang Api rose to altitudes of 2.4-2.7 km (8,000-9,000 ft) a.s.l. and drifted NW and W. Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Aira (Japan) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Aira Ryukyu Volcanic Arc	JMA reported two events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 24-28 July. One of the events generated an ash plume that rose 2 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale). Source: Japan Meteorological Agency (JMA)
Bagana (Papua New Guinea) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Bagana Solomon Volcanic Arc	Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 1 August an ash plume from Bagana drifted W at an altitude of 2.1 km (7,000 ft) a.s.l. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Bezymianny (Russia) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Bezymianny Eastern Kamchatka Volcanic Arc	KVERT reported that during 21-28 July a thermal anomaly was identified daily over Bezymianny in satellite images. A lava flow continued to flow down the W flank of the dome. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Bogoslof (United States) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Bogoslof Aleutian Ridge Volcanic Arc	AVO reported that during 26 July-1 August no activity at Bogoslof was observed in partly cloudy to clear satellite images, and no activity was detected in seismic, infrasound, or lightning data. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Cleveland (United States) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Cleveland Aleutian Ridge Volcanic Arc	AVO reported that during 26 July-1 August no activity was observed in seismic or infrasound data at Cleveland. The small lava dome on the floor of the crater had grown from 30 m in diameter to 42, and continued to inflate; the surface area of the dome was at least 50 x 45 m (~2,100 square meters), which was an increase of about 75% since 25 July (~1,200 square meters). Steam plumes rising from the crater were recorded by the webcam during 25 and 29-30 July, and elevated surface temperatures (consistent with lava-dome growth) were identified in satellite images during 30 July-1 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Colima (Mexico) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Colima Trans-Mexican Volcanic Belt	On 2 June the Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima reported that during the previous week seismic data revealed 45 high-frequency events, 12 long-period events, 1.2 hours of tremor, 3 landslides, and one low-intensity explosion. Two lahars descended the La Lumbre ravine (SW) and three descended the Montegrande ravine (SSE); both ravines are in Colima state. Source: Centro Universitario de Estudios Vulcanológicos (CUEV) - Universidad de Colima
Dukono (Indonesia) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Dukono Halmahera Volcanic Arc	Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 26 July-1 August ash plumes from Dukono rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted in multiple directions. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Kilauea (United States) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	During 26 July-1 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Several large cracks running parallel to the coastline spanned the width of the delta. Surface lava flows were active above the pali and on the coastal plain about 2 km upslope from the gravel emergency route. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Klyuchevskoy (Russia) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Klyuchevskoy Eastern Kamchatka Volcanic Arc	KVERT reported that during 22-27 July ash plumes from Klyuchevskoy were identified in satellite images drifting 120 km E and NE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Poas (Costa Rica) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Poas Central America Volcanic Arc	OVSICORI-UNA reported that on 1 August an event at Poás passively produced a plume that rose 500 m above the crater. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Sabancaya (Peru) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Sabancaya Central Andean Volcanic Arc	Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; there was an average of 40 explosions recorded per day during 24-30 July. Gas-and-ash plumes rose 5 km above the crater rim and drifted more than 50 km NW and SE. Sulfur dioxide flux was as high as 2,530 tons per day, recorded on 28 July. The MIROVA system detected nine thermal anomalies. Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET), Instituto Geofísico del Perú (IGP)
Sheveluch (Russia) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	KVERT reported that a thermal anomaly was identified daily during 21-28 July in satellite images over Sheveluch. Strong explosions on 23 July generated ash plumes that rose 11-12 km (36,100-39,400 ft) a.s.l. and during 23-24 July drifted 1,400 km E. The Aviation Color Code remained at Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Sinabung (Indonesia) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Sinabung Sunda Volcanic Arc	Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 26-29 and 31 July ash plumes from Sinabung rose 3.3-4.6 km (11,000-15,000 ft) a.s.l. and drifted NE, ENE, and ESE. Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Turrialba (Costa Rica) | 26 July-1 August 2017 | Continuing ActivityCite this Report
Turrialba Central America Volcanic Arc	OVSICORI-UNA reported that on 26 July an event at Turrialba passively produced a plume that rose 300 m above the crater and drifted SW. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,627 individual reports over 1,243 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.

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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)