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Smithsonian / USGS Weekly Volcanic Activity Report

Weekly Volcanic Activity Map

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday and averaging 16 reported volcanoes, this is not a comprehensive list of all eruptions this week, but rather a summary of activity that meet criteria discussed in the "Criteria and Disclaimers" section below.

Volcanic activity reported here is preliminary and subject to change. Carefully reviewed, detailed narratives over longer time periods are published as reports of the Bulletin of the Global Volcanism Network available through volcano profile pages.

Smithsonian / USGS Weekly Volcanic Activity Report for the week of 15 April-21 April 2015
Name Location Eruption Start Date Report Status
Chikurachki Paramushir Island (Russia) 2022 Jan 17 New
Raung Eastern Java New
Sinabung Northwestern Sumatra New
Tongariro North Island (New Zealand) New
Tungurahua Ecuador New
Ubinas Peru New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Chirinkotan Kuril Islands (Russia) Continuing
Chirpoi Kuril Islands (Russia) Continuing
Colima Mexico Continuing
Dukono Halmahera 1933 Aug 13 Continuing
Fuego South-Central Guatemala 2002 Jan 4 Continuing
Karymsky Eastern Kamchatka (Russia) Continuing
Kilauea Hawaiian Islands (USA) 2021 Sep 29 Continuing
Klyuchevskoy Central Kamchatka (Russia) Continuing
Popocatepetl Mexico 2005 Jan 9 Continuing
Reventador Ecuador 2008 Jul 27 Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Shishaldin Fox Islands (USA) Continuing
Tengger Caldera Eastern Java Continuing
Turrialba Costa Rica Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 18,389 individual reports over 1,142 weeks (average of 16 per week) on 328 different volcanoes.

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Use the dropdowns to choose the year and week for archived Weekly Reports.

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Agung Cotopaxi Iliamna Little Sitkin Planchon-Peteroa Stromboli
Ahyi Cuicocha Iliwerung Llaima Poas Sulu Range
Aira Cumbal Inielika Lokon-Empung Popocatepetl Sumbing
Akan Dabbahu Ioto Lonquimay Purace Sundoro
Alaid Davidof Irazu Lopevi Puyehue-Cordon Caulle Suretamatai
Alu-Dalafilla Dempo Iya Machin Rabaul Suwanosejima
Ambae Descabezado Grande Izu-Torishima Makushin Raikoke Taal
Ambang Dieng Volcanic Complex Jackson Segment Maly Semyachik Ranakah Tair, Jebel at
Ambrym Dukono Kaba Manam Raoul Island Takawangha
Anatahan Ebeko Kadovar Manda Hararo Rasshua Talang
Aniakchak Ebulobo Kaitoku Seamount Marapi Raung Tambora
Antillanca Volcanic Complex Edgecumbe Kama'ehuakanaloa Maroa Redoubt Tanaga
Antuco Egon Kambalny Martin Reventador Tandikat-Singgalang
Apoyeque Ekarma Kanaga Masaya Reykjanes Tangkoko-Duasudara
Arenal Epi Kanlaon Maule, Laguna del Rincon de la Vieja Tangkuban Parahu
Asamayama Erebus Karangetang Mauna Loa Rinjani Tara, Batu
Askja Erta Ale Karkar Mayon Ritter Island Ta'u
Asosan Etna Karthala McDonald Islands Rotorua Taupo
Atka Volcanic Complex Etorofu-Yakeyama [Grozny Group] Karymsky Melimoyu Ruang Telica
Augustine Eyjafjallajokull Kasatochi Merapi Ruapehu Tenerife
Avachinsky Fagradalsfjall Katla Midagahara Ruiz, Nevado del Tengger Caldera
Awu Fernandina Katmai Misti, El Sabancaya Three Sisters
Axial Seamount Fogo Kavachi Miyakejima Sakar Tinakula
Azul, Cerro Fonualei Kelimutu Momotombo Salak Tofua
Azumayama Fournaise, Piton de la Kelud Monowai San Cristobal Tokachidake
Bagana Fourpeaked Kerinci Montagu Island San Miguel Tolbachik
Balbi Fuego Ketoi Moyorodake [Medvezhia] San Vicente Toliman
Bamus Fujisan Kharimkotan Mutnovsky Sangay Tongariro
Banda Api Fukutoku-Oka-no-Ba Kick 'em Jenny Myojinsho Sangeang Api Trident
Bardarbunga Galeras Kie Besi Nabro Santa Ana Tungurahua
Barren Island Galunggung Kikai Negra, Sierra Santa Maria Turrialba
Batur Gamalama Kilauea Negro, Cerro Sao Jorge Ubinas
Bezymianny Gamkonora Kirishimayama Nightingale Island Sarigan Ugashik-Peulik
Bogoslof Gareloi Kita-Ioto Nishinoshima Sarychev Peak Ukinrek Maars
Brava Gaua Kizimen Nisyros Saunders Ulawun
Bristol Island Gorely Klyuchevskoy Novarupta Savo Unnamed
Bulusan Great Sitkin Kolokol Group NW Rota-1 Semeru Unnamed
Calbuco Grimsvotn Koryaksky Nyamulagira Semisopochnoi Veniaminof
Callaqui Guagua Pichincha Krakatau Nyiragongo Seulawah Agam Villarrica
Cameroon Guallatiri Krummel-Garbuna-Welcker Ofu-Olosega Sheveluch Vulcano
Campi Flegrei del Mar di Sicilia Guntur Krysuvik-Trolladyngja Okataina Shishaldin West Mata
Cayambe Hachijojima Kuchinoerabujima Okmok Simbo Westdahl
Chachadake [Tiatia] Hakoneyama Kurikomayama Ontakesan Sinabung Whakaari/White Island
Chaiten Heard Kusatsu-Shiranesan Oraefajokull Sinarka Witori
Chiginagak Hekla Kverkfjoll Osorno Siple Wolf
Chikurachki Helgrindur La Palma Pacaya Sirung Yakedake
Chiles-Cerro Negro Hierro Lamington Pagan Slamet Yasur
Chillan, Nevados de Hokkaido-Komagatake Lamongan Palena Volcanic Group Snaefellsjokull Yufu-Tsurumi
Chirinkotan Home Reef Langila Paluweh Soputan Zaozan [Zaosan]
Chirpoi Hood Lanin Panarea Sorikmarapi Zavodovski
Ciremai Huaynaputina Lascar Papandayan Sotara Zhupanovsky
Cleveland Hudson, Cerro Lateiki Parker Soufriere Hills Zubair Group
Colima Huila, Nevado del Lengai, Ol Doinyo Pavlof Soufriere St. Vincent
Colo Hunga Tonga-Hunga Ha'apai Leroboleng Pelee South Sarigan Seamount
Concepcion Ibu Lewotobi Peuet Sague Spurr
Copahue Ijen Lewotolok Pinatubo St. Helens
 News Feeds and Google Placemarks


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The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. At the end of each report is a list of the sources used. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. This feature was first made available on 5 March 2008.



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A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

 Criteria & Disclaimers

Criteria



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.

Disclaimers



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)

Report for Chikurachki
An observer from Severo-Kurilsk (60 km NW, Paramushir Island) reported that on 18 April a gas-and-steam plume from Chikurachki contained a small amount of ash. The Aviation Color Code was raised to Yellow.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Raung
PVMBG reported that, during infrequent times of clear weather in December 2014 and January 2015, white plumes were observed rising as high as 500 m above Raung's crater rim. In February and during 1-14 March plumes were gray-white and rose to a maximum height of 200 m. Crater incandescence and rumbling was reported. During 15 March-7 April emissions were gray-brown and rose as high as 200 m; rumbling continued to be heard. During 8-15 April gray-brown plumes rose as high as 300 m. Rumbling was heard on 8 April and crater incandescence was observed on 12 April. Continuous tremor was recorded during December 2014-12 January 2015; tremor was not continuous starting on 13 January, and RSAM values declined. The Alert Level remained at 2 (on a scale of 1-4).
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Sinabung
PVMBG reported that during 6-12 April white plumes rose as high as 500 m above Sinabung; misty conditions prevented observations on 13 April. Lava was incandescent as far from the lava dome as 1.5 km S and SE. The main lava flow remained 2.9 km long. After pyroclastic flows descended the flanks on 2 April, a new lava flow from the growing dome formed near the crater and traveled 170 m SSE. Seismicity consisted of avalanche signals, low-frequency and hybrid events, local and far tectonic events, and volcanic earthquakes. Overall seismicity decreased compared to 30 March-6 April. Tilt and EDM (Electronic Distance Measurement) data fluctuated but showed overall deflation. The Alert Level remained at 3 (on a scale of 1-4). Visitors and tourists were prohibited from approaching the crater within a radius of 6 km on the S, 5 km on the SE, and 3 km in other directions.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Tongariro
On 20 April GeoNet reported that it had been three weeks since anomalous seismicity at Tongariro's Ngauruhoe cone had been detected. In addition, no anomalous ground temperatures or unusual levels of gas emissions were detected at the summit during fieldwork, indicating that the minor unrest had ceased. The Volcanic Alert Level was lowered to 0 (on a scale of 0-5).
Source: GeoNet
Report for Tungurahua
IG reported moderate-to-high activity at Tungurahua during 15-21 April; gas, water vapor, and/or ash plumes were noted daily, although cloud cover often prevented observations. Explosions on 15 April generated ash plumes that rose 3 km above the crater, followed by water vapor-and-ash emissions that rose 2 km and drifted WSW. On 17 April constant gas emissions with minor ash content rose 500-1,000 m and drifted W.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Ubinas
According to Observatorio Volcanológico del Sur (OVS) and Observatorio Vulcanológico del INGEMMET (OVI), six explosions from Ubinas were recorded during 15-17 April, producing ash plumes that drifted 15 km SW, S, and SE. The largest ash plume, generated from an explosion detected at 0759 on 15 April, rose 3.5 km. The other explosions (at 1408 on 15 April, at 0600 on 16 April, and at 0743, 0936, and 1518 on 17 April) generated ash plumes that rose 1.5-1.8 km. Seismicity consisting of tornillos, hybrid events, and long-period events decreased from the previous week; the dominant signal was tremor characteristic of emissions and hydrothermal activity.
Sources: Instituto Geofísico del Perú (IGP), Instituto Geológico Minero y Metalúrgico (INGEMMET)
Report for Aira
JMA reported 23 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano during 13-17 April. Incandescence from the crater was visible at night on 14 April. An explosion at 1355 on 17 April generated a large ash plume that rose 3 km above the crater, and a second explosion ejected tephra as far as 1,800 m. Inflation continued to be detected. The Alert Level remained at 3 (on a scale of 1-5). Based on JMA notices, the Tokyo VAAC reported that explosions during 15-18 and 20-21 April generated plumes which rose to altitudes of 1.2-4.6 km (4,000-15,000 ft) a.s.l. and drifted E and SE.
Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Chirinkotan
SVERT reported that during 17-18 April a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 13-20 April. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Chirpoi
SVERT reported that satellite images over Snow, a volcano of Chirpoi, detected a thermal anomaly on 14 and 17 April. Weak steam-and-gas emissions were also observed on 17 April. Cloud cover obscured views on other days during 13-20 April. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Colima
Based on satellite images, and webcam views, information from Colima University, Jalisco Civil Protection notices, Mexico City MWO notices, and wind data, the Washington VAAC reported multiple ash emissions per day from Colima during 15-20 April. Ash plumes rose to altitudes of 5.5-8.5 km (15,000-26,000 ft) a.s.l. and drifted NNE to E. Thermal anomalies were detected on 15 and 17 April. According to a news article ashfall was reported to the W in Guzman on 16 April.
Sources: Washington Volcanic Ash Advisory Center (VAAC), Agence France-Presse (AFP)
Report for Dukono
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 15-16 April ash plumes from Dukono rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted 45-65 km E, SE, and S.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Fuego
INSIVUMEH reported that during 15-17 April explosions at Fuego generated ash plumes that rose 650-850 m above the crater and drifted 8-11 km S, SW, and W. Incandescent tephra was ejected 150-200 m above the crater. Avalanches originated from the end of a 300-m-long lava flow in the Trinidad drainage. In a special report from 18 April INSIVUMEH noted that lava effusion had ended at 1730 that day. The activity that followed was characterized by explosions occurring at a rate of 2-4 per hour and crater incandescence. During 19-20 April explosions occurring at a rate of 2-3 per hour generated ash plumes that rose 450-750 m and drifted 4-6 km W and NW. Incandescent tephra was ejected 100 m high and avalanches descended the Ceniza and Trinidad drainages. Explosions during 20-21 April produced ash plumes that rose 550 m and drifted 7 km W and NW. Incandescent tephra was again ejected 100 m high.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Karymsky
KVERT reported moderate activity at Karymsky during 10-17 April, although satellite images showed no activity. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
During 15-21 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a, and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. The thermal webcam recorded multiple incandescent outgassing vents in the crater. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. On 16 April several small lava flows extruded from two S vents on Pu'u 'O'o's crater floor.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Klyuchevskoy
On 18 April KVERT reported that Strombolian activity at Klyuchevskoy continued. A webcam recorded a narrow ash plume that rose 1-2 km and drifted 100 km SE. The Aviation Color Code was raised to Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Popocatepetl
CENAPRED reported that during 15-21 April the seismic network at Popocatépetl recorded 19-157 daily emissions. Cloud cover sometimes prevented observations of the crater, although ash plumes and nighttime crater incandescence were often noted. Explosions at 0617 and 0857 on 15 April generated ash plumes that rose 1 km and drifted E. On 17 April an explosion was detected as well as a steam-and-gas emission with low ash content that rose 1-2 km. The next day, on 18 April, six explosions generated steam-and-gas plumes with small amounts of ash that rose as high as 1.5 km and drifted NE. A series of smaller, low-intensity explosions between 1636 and 2330 produced emissions of steam, gas, and small amounts of ash that rose 300 m and drifted NE. Some incandescent tephra fell 100-500 m away onto the N and NE flanks. On 19 April seven explosions generated steam-and-gas plumes with small amounts of ash that rose as high as 1.5 km and drifted NE. At 1052 on 20 April an explosion produced an ash plume that rose 3 km and drifted E. Incandescent tephra was ejected 500 m E. On 21 April three explosions generated plumes with some ash that rose 500 m.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Reventador
During 15-21 April IG reported moderate seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador; cloud cover often prevented visual observations. During 15-16 April steam-and-ash plumes rose 500-1,000 m above the crater and drifted SW. On 18 April an emission of water vapor with minor ash content rose 800 m and drifted SW.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Sheveluch
KVERT reported that during 10-17 April lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, and fumarolic activity. Several ash plumes rose to an altitude of 7 km (23,000 ft) a.s.l. Satellite images showed ash plumes drifting as far as 380 km E and SE during 9-11 and 13-16 April. A daily thermal anomaly was also detected. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Shishaldin
AVO reported that seismicity at Shishaldin continued to be elevated over background levels 15-21 April indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover frequently prevented satellite and webcam observations. On 16 April the webcam periodically recorded a white steam plume rising about 500 m above the summit. Several pilot reports indicated ash emissions, prompting a SIGMET, however no ash was visible in satellite or webcam images, and seismicity remained unchanged. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Tengger Caldera
PVMBG reported that during January-10 April white plumes from Tengger Caldera's Bromo cone rose 50-100 m above the crater. A sulfur dioxide odor was noted at the Bromo observation post. Seismicity was dominated by tremor, but also consisted of volcanic earthquakes, shallow volcanic earthquakes, and distant tectonic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the crater within a radius of 1 km.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Turrialba
The Washington VAAC reported that ash emissions from Turrialba were visible in the webcam on 20 April; weather clouds prevented ash detected in satellite images. Images later that day showed steam plumes with minor ash content.
Source: Washington Volcanic Ash Advisory Center (VAAC)