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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 29 March-4 April 2023
Name Country Eruption Start Date Report Status
Ambae Vanuatu New
Kikai Japan 2023 Mar 27 New
Laguna del Maule Chile New
Nevado del Ruiz Colombia 2014 Nov 18 New
Ubinas Peru New
Ahyi United States Continuing
Aira Japan 2017 Mar 25 Continuing
Asamayama Japan Continuing
Bezymianny Russia 2016 Dec 5 Continuing
Cotopaxi Ecuador Continuing
Ebeko Russia 2022 Jun 11 Continuing
Fuego Guatemala 2002 Jan 4 Continuing
Great Sitkin United States 2021 May 25 Continuing
Karangetang Indonesia 2018 Nov 25 Continuing
Krakatau Indonesia Continuing
Lewotolok Indonesia 2020 Nov 27 Continuing
Merapi Indonesia 2020 Dec 31 Continuing
Reventador Ecuador 2008 Jul 27 Continuing
Sangay Ecuador 2019 Mar 26 Continuing
Santa Maria Guatemala 1922 Jun 22 Continuing
Semeru Indonesia 2017 Jun 6 Continuing
Semisopochnoi United States Continuing
Sheveluch Russia 1999 Aug 15 Continuing
Stromboli Italy 1934 Feb 2 Continuing
Suwanosejima Japan 2004 Oct 23 Continuing
Ulawun Papua New Guinea Continuing
Yasur Vanuatu 1270 ± 110 years Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,115 individual reports over 1,220 weeks (average of 16 per week) on 333 different volcanoes.

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Agung Cotopaxi Iliamna Little Sitkin Poas Sulu Range
Ahyi Cuicocha Iliwerung Llaima Popocatepetl Sumbing
Aira Cumbal Inielika Lokon-Empung Purace Sundoro
Akan Dabbahu Ioto Lonquimay Puyehue-Cordon Caulle Suretamatai
Alaid Davidof Irazu Lopevi Rabaul Suwanosejima
Alu-Dalafilla Dempo Iya Machin Raikoke Taal
Ambae Descabezado Grande Izu-Torishima Makushin Ranakah Tair, Jebel at
Ambang Dieng Volcanic Complex Jackson Segment Maly Semyachik Raoul Island Takawangha
Ambrym Dukono Kaba Manam Rasshua Talang
Anatahan East Epi Kadovar Manda Hararo Raung Tambora
Aniakchak Ebeko Kaitoku Seamount Marapi Redoubt Tanaga
Antillanca Volcanic Complex Ebulobo Kama'ehuakanaloa Maroa Reventador Tandikat-Singgalang
Antuco Edgecumbe Kambalny Martin Reykjanes Tangkoko-Duasudara
Apoyeque Egon Kanaga Masaya Rincon de la Vieja Tangkuban Parahu
Arenal Ekarma Kanlaon Maule, Laguna del Rinjani Tara, Batu
Asamayama Eldey Karangetang Mauna Loa Ritter Island Ta'u
Askja Erebus Karkar Mayon Rotorua Taupo
Asosan Erta Ale Karthala McDonald Islands Ruang Telica
Atka Volcanic Complex Etna Karymsky Melebingoy Ruapehu Tenerife
Augustine Etorofu-Yakeyama [Grozny Group] Kasatochi Melimoyu Ruby Tengger Caldera
Avachinsky Eyjafjallajokull Katla Merapi Ruiz, Nevado del Three Sisters
Awu Fagradalsfjall Katmai Midagahara Sabancaya Tinakula
Axial Seamount Fernandina Kavachi Misti, El Sakar Tofua
Azul, Cerro Fogo Kelimutu Miyakejima Salak Tokachidake
Azumayama Fonualei Kelud Momotombo San Cristobal Tolbachik
Bagana Fournaise, Piton de la Kerinci Monowai San Miguel Toliman
Balbi Fourpeaked Ketoi Montagu Island San Vicente Tongariro
Bamus Fuego Kharimkotan Moyorodake [Medvezhia] Sangay Trident
Banda Api Fujisan Kick 'em Jenny Mutnovsky Sangeang Api Tungurahua
Bardarbunga Fukutoku-Oka-no-Ba Kie Besi Myojinsho Santa Ana Turrialba
Barren Island Galeras Kikai Nabro Santa Maria Ubinas
Batur Galunggung Kilauea Negra, Sierra Sao Jorge Ugashik-Peulik
Bezymianny Gamalama Kirishimayama Negro, Cerro Sarigan Ukinrek Maars
Bogoslof Gamkonora Kita-Ioto Nightingale Island Sarychev Peak Ulawun
Brava Gareloi Kizimen Nishinoshima Saunders Unnamed
Bristol Island Gaua Klyuchevskoy Nisyros Savo Unnamed
Bulusan Gorely Kolokol Group Novarupta Semeru Veniaminof
Calbuco Great Sitkin Koryaksky NW Rota-1 Semisopochnoi Villarrica
Callaqui Grimsvotn Krakatau Nyamulagira Seulawah Agam Vulcano
Cameroon Guagua Pichincha Krummel-Garbuna-Welcker Nyiragongo Sheveluch West Mata
Campi Flegrei Guallatiri Krysuvik-Trolladyngja Ofu-Olosega Shishaldin Westdahl
Campi Flegrei del Mar di Sicilia Guntur Kuchinoerabujima Okataina Simbo Whakaari/White Island
Cayambe Hachijojima Kurikomayama Okmok Sinabung Witori
Chachadake [Tiatia] Hakoneyama Kusatsu-Shiranesan Ontakesan Sinarka Wolf
Chaiten Heard Kverkfjoll Oraefajokull Siple Wrangell
Chiginagak Hekla La Palma Osorno Sirung Yakedake
Chikurachki Helgrindur Lamington Pacaya Slamet Yasur
Chiles-Cerro Negro Hierro Lamongan Pagan Snaefellsjokull Yufu-Tsurumi
Chillan, Nevados de Hokkaido-Komagatake Langila Palena Volcanic Group Soputan Zaozan [Zaosan]
Chirinkotan Home Reef Lanin Paluweh Sorikmarapi Zavodovski
Chirpoi Hood Lascar Panarea Sotara Zhupanovsky
Ciremai Huaynaputina Late Papandayan Soufriere Hills Zubair Group
Cleveland Hudson, Cerro Lateiki Pavlof Soufriere St. Vincent
Colima Huila, Nevado del Lengai, Ol Doinyo Pelee South Sarigan Seamount
Colo Hunga Tonga-Hunga Ha'apai Leroboleng Peuet Sague Spurr
Concepcion Ibu Lewotobi Pinatubo St. Helens
Copahue Ijen Lewotolok Planchon-Peteroa Stromboli
 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 Ambae
On 30 March the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that the cone in Ambae’s Lake Voui continued to produce emissions consisting of steam, volcanic gases, and possibly occasional ash that drifted downwind. Volcanic earthquakes were recorded by the seismic network. According to the Wellington VAAC a low-level ash plume rose to an altitude of 2.4 km based on satellite imagery on 5 April. The Alert Level remained at 2 (on a scale of 0-5) and the public was warned to stay outside of the Danger Zone, defined as a 2-km radius around the active vents in Lake Voui, and away from drainages during heavy rains. Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD), Wellington VAAC
Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Wellington Volcanic Ash Advisory Center (VAAC)
Report for Kikai
JMA reported that minor eruptive activity was recorded at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim, during 27 March-3 April. White gas-and-steam plumes rose 700 m above the crater rim. Surveillance cameras observed nightly incandescence. The Alert Level remained at 2 (on a 5-level scale), and residents were warned to stay 500 m away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Laguna del Maule
SERNAGEOMIN reported that increased seismicity at Laguna del Maule was first registered around 1800 on 30 March. The seismic monitoring stations recorded a swarm of 300 volcano-tectonic earthquakes that occurred in an elongated area in a NW-SE direction approximately 10 km SW of the crater at a depth of up 8 km. These events were associated with rock fracturing processes. Starting on 3 April there was an increase in the magnitude of the earthquakes at M 2.5, M 2.8, and M 2.9 at depths of 4.5-8 km. The Alert Level was raised to Yellow, the second lowest on a four-color scale on 3 April.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
Report for Nevado del Ruiz
Servicio Geológico Colombiano’s (SGC) reported that thermal anomalies, persistent in Arenas Crater at Nevado del Ruiz since October 2022, were low-to-moderate in intensity. Seismicity increased significantly on 24 March, characterized by rock-fracturing earthquakes mainly located 2-5 km SW of Arenas crater at depths of 2-4 km. On 28 March there were 6,500 of these events, the highest daily count since 2010. The number of daily events continued to increase and on 29 March the seismic network recorded 11,000 earthquakes, the highest daily count since seismic monitoring began in 1985; on 30 March there were 11,600 earthquakes. The maximum magnitudes per day were also increasing, with a M 2.6 on 24 March, a M 2.7 on 29 March, and a M 3.1 on 30 March. The earthquake locations migrated towards Arenas Crater, though the depths remained within the same range. The Alert Level was raised to Orange, Level II (the second highest level on a four-level scale) on 30 March. In addition to the swarm, seismic signals indicating fluid movement continued to be recorded and some were associated with ash emissions; the tallest plume on 30 March rose 1.8 km above the summit and drifted NW and SW.

The number of earthquakes on 31 March totaled 8,800 with a maximum magnitude of 2.6 event at 1236. The number of signals indicating fluid movement increased during 31 March-1 April and were likely associated with ash emissions. Gas-and-ash plumes rose as high as 1.3 km above the summit and drifted SW and SE. A total of 10,400 earthquakes were recorded on 1 April with the largest event, a M 3.1, recorded at 1040. On 2 April a total of 5,400 earthquakes were recorded and the largest event (M 2.3) occurred at 1122 and was located 4.3 km SW of the crater. Ash-and-gas emissions persisted and rose to 1.2 km above the summit and drifted SW and NW. Ashfall was reported in Brisas y de Potosí by Parque Nacional Natural Los Nevados officials. The Gestión del Riesgo de Desastres (UNGRD) reported that there were 57,000 people living in 22 municipalities in the departments of Tolima, Caldas, Risaralda, Valle del Cauca, Quindío, and Cundinamarca who could be impacted by Nevado del Ruiz. Preparations and coordination for a possible evacuation of residents were centered on areas in high-risk zones including the municipalities of Villamaría in the department of Caldas, Casabianca, Herveo, Murillo, and Villahermosa in Tolima, and the sector of the Gualí River in the municipality of Guaduas, Cundinamarca.
Sources: Servicio Geológico Colombiano (SGC), Gestión del Riesgo de Desastres (UNGRD)
Report for Ubinas
Instituto Geofísico del Perú (IGP) reported that at 1713 on 28 March a moderate-volume lahar descended the Volcánmayo drainage on Ubinas’s SE flank. The town of Tonohaya (7 km SSE) is located along the drainage and the town of Ubinas is 2 km E of the drainage. The Alert Level remained at Yellow (the second lowest level on a four-color scale). [Correction: The Alert Level was at Green, the lowest level.]
Source: Instituto Geofísico del Perú (IGP)
Report for Ahyi
Unrest at Ahyi Seamount continued during 28 March-4 April. Underwater events were detected by pressure sensors on Wake Island, 2,270 km E, on 29 and 31 March and during 1-2 April. The events were possibly related to underwater explosions or earthquakes at the volcano. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).
Source: US Geological Survey
Report for Aira
JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Caldera's Sakurajima volcano) during 27 March-4 April with nightly crater incandescence. Five eruptive events were recorded during 27-31 March producing plumes that rose 1.5 km above the crater rim. A few small eruptive events occasionally occurred during the rest of the week. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from both craters.
Source: Japan Meteorological Agency (JMA)
Report for Asamayama
JMA reported that inflation on Asamayama's W flank persisted during 29 March-4 April, and the number of shallow volcanic earthquakes continued to increase. There were 95 events on 29 March, 91 on 30 March, 94 on 31 March, 77 on 1 April, 68 on 2 April, 104 on 3 April, and 149 on 4 April. Sulfur dioxide measurements were 1,600 tons per day on 29 March, which had increased compared to the previous measurement of 100 tons per day on 17 March. On 3 April the sulfur dioxide concentration was 1,000 tons per day. The Alert Level remained at a 2 (on a scale of 1-5) and warned the public to be aware of large volcanic blocks and pyroclastic flows within 2 km of the crater.
Source: Japan Meteorological Agency (JMA)
Report for Bezymianny
KVERT reported that a thermal anomaly over Bezymianny persisted in satellite images at least through 31 March, local time. On 2 April an ash plume rose 4.3 km (14,000 ft) a.s.l. and drifted SE according to the Tokyo VAAC. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Cotopaxi
IG reported that eruptive activity at Cotopaxi was ongoing during 29 March-4 April. Gas-and-ash plumes visible in webcam images and reported by the Washington VAAC during 28-29 March rose as high as 2 km above the summit and drifted SE and N. Minor ashfall was reported in Machachi (23 km NW), El Chasqui (17 km W), and Latacunga (34 km SW). Gas-and-steam plumes were seen rising 100-300 m during 30-31 March. Ash-and-gas plumes rose as high as 1 km and drifted W during 1-2 April. Gas-and-steam plumes rose 1 km and drifted W on 3 April. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)
Report for Ebeko
KVERT reported that moderate activity at Ebeko was ongoing during 23-30 March. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 23, 26, and 29-30 March generated ash plumes that rose as high as 2.8 km (9,200 ft) a.s.l. and drifted NE and E. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Fuego
INSIVUMEH reported that 4-12 explosions per hour recorded at Fuego during 29 March-4 April generated ash plumes that rose as high as 4.8 km above sea level (15,700 ft a.s.l.) and drifted at least 10 km W, NW, SE, SW. Weak to moderate rumbling accompanied the explosions, vibrating the roofs and windows of nearby houses. During the night and early morning incandescent material was ejected 100-200 m above the crater. Daily block avalanches descended all the flanks toward the Seca (W), Taniluya (SW), Ceniza (SSW), Trinidad (S), Las Lajas (SE), El Jute (ESE), Honda (E), and Santa Teresa drainages, sometimes reaching vegetated areas. Some avalanches resuspended ash to 100 m high. Ashfall was reported almost daily in areas downwind including Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Finca Asunción, Yepocapa (8 km NW), La Rochela, El Porvenir (8 km ENE), Finca Palo Verde, Aldeas, Sangre de Cristo (8 km WSW), Quisaché, and Ojo de Agua.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Great Sitkin
AVO reported that lava likely continued to slowly effuse at the summit of Great Sitkin during 29 March-4 April, producing a thick lava flow. Minor earthquakes and seismic events were noted during 1-2 April. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Karangetang
During 29 March-4 April a webcam image of Karangetang captured in the PVMBG daily reports showed incandescent material at the summit Main Crater (S crater) and on the flanks at 0016 on 1 April. The Alert Level remained at 3 (on a scale of 1-4) and the public were advised to stay 2.5 km away from Main Crater with an extension to 3.5 km on the S and SE flanks.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Krakatau
PVMBG reported that daily white steam-and-gas plumes rose as high as 300 m above Anak Krakatau’s summit during 29 March-4 April. White-and-gray plumes rose 50-200 m above the summit and drifted NE on 2 April. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay at least 5 km away from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Lewotolok
PVMBG reported that the eruption at Lewotolok was ongoing during 29 March-4 April. White gas plumes rose as high as 700 m above the summit and drifted in multiple directions during 29 March and 1-2 April. White-and-gray ash plumes of variable densities rose 100-750 m above the summit and drifted in multiple directions during 30-31 March and during 3-4 April. A webcam image from 0050 on 4 April showed summit incandescence. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Merapi
BPPTKG reported that the eruption at Merapi (on Java) continued during 24-30 March and seismicity remained at high levels. The SW lava dome produced 176 lava avalanches that traveled as far as 2 km down the SW flank (upstream in the Bebeng and Boyong drainages). Two pyroclastic flows traveled 1 km down the SW flank, upstream of the Boyong drainage. Morphological changes to the SW lava dome were evident in webcam images due to continuing collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location.
Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)
Report for Reventador
IG described the ongoing eruption at Reventador as moderate during 29 March-4 April. Seismicity was characterized by explosions, long-period earthquakes, periods of harmonic tremor, and signals that indicated emissions. The number of daily explosions ranged from 24 to 45; though the daily seismic data transmission was sometimes interrupted. Steam, gas, and ash plumes were observed in IG webcam images and described in Washington VAAC advisories during 29-31 March; weather conditions occasionally prevented views. The plumes rose as high as 1.3 km above the summit and drifted W. Crater incandescence was visible during the night of 29 and 30 March. Incandescent blocks were seen rolling as far as 700 m down the flanks in all directions during 30-31 March. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Orange (the second highest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)
Report for Sangay
IG reported a high level of activity at Sangay during 29 March-4 April, which included daily explosions, periods of tremor, and gas, steam, ash emissions. The daily count of explosions ranged from 7-72, though the daily seismic data transmission was sometimes interrupted. Almost daily gas, steam, and ash plumes were either observed in IG webcam images or described in Washington VAAC volcanic activity notifications; weather clouds often prevented observations of the summit. The plumes rose as high as 1.4 km above the volcano and drifted W. TROPOMI data from the Sentinel-5P satellite showed that sulfur dioxide plumes contained 183-2,049 tons/day. Multiple thermal anomalies were identified in satellite images on most days. Incandescence from the crater and an avalanche of material on the SE flank were visible during the night of 30 March; only crater incandescence was visible during the night of 31 March. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)
Report for Santa Maria
INSIVUMEH reported that the Santa Maria-Santiaguito lava dome complex remained highly active during 29 March-4 April. Seismic stations and webcams recorded weak-to-moderate explosions which produced ash plumes to 4.3 km altitude (14,100 ft a.s.l.). Incandescence from the dome and along lava flow margins was visible most nights or early mornings. Weak-to-moderate block-and-ash flows were recorded around the crater, on the S, W, SE, SW, and E flanks, and at the front of the western lava flow. Ash plumes rose 3.5 km above the crater and drifted W on 31 March. Avalanches traveled down the S, SW, E, and N flanks; on 31 March the avalanches were accompanied by small pyroclastic flows. The active lava flow measured 4.3 km long in the WSW direction down the San Isidro and Zanión Seco drainages on 1 April, with some block collapses that generated ash clouds several hundred meters high. On 4 April ash plumes rose 3.5 km above the crater and drifted W and the active lava flow generated avalanches and moderate-to-strong pyroclastic flows.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semeru
PVMBG reported that the eruption at Semeru continued during 29 March-4 April, with almost daily emissions of dense ash plumes; weather conditions prevented views on 30 March. Several Volcano Observatory Notices for Aviation (VONAs) were issued through the week. At 0714 on 29 March a dense gray ash plume rose 500 m above the summit and drifted N and NE. At 0517, 0605, and 0704 on 31 March dense white-to-gray ash plumes rose as high as 1 km and drifted NE, N, and NW. At 0552 and 0804 on 1 April and 0532, 0622, and 1630 on 2 April white-to-gray ash plumes rose 500-800 m and drifted N, SE, S, and SW. At 0538 and 0630 white-to-gray ash plumes rose as high as 1.2 km and drifted S and SE. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 100 m away from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Semisopochnoi
AVO reported that low-level unrest continued at Semisopochnoi during 28 March-4 April. Steam emissions from the N crater of Mount Young were visible in webcam images during 29-30 March; weather clouds obscured webcam and satellite views during most of the week. Minor seismic and infrasound signals were recorded during 31 March-1 April that may or may not have been related to activity at N crater. Local earthquakes and periods of tremor occurred during 1-2 April. A 200-km-long gas-and-steam emission was visible at low altitudes during the night of 3 April; no ash signatures were detected in the cloud. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that the ongoing eruption at Sheveluch was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A daily thermal anomaly was identified in satellite images during 23-30 March. Ash plumes drifted 80 km E during 25-26 and 28-30 March. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Stromboli
INGV reported that both explosive and effusive activity at Stromboli occurred during 27 March-2 April, though inclement weather conditions often prevented views on most days. Activity was centered at three vents (two at crater N1 and one at crater N2) in Area N, within the upper part of the Sciara del Fuoco, and from three vents in the Area C-S (South-Central Crater area) in the crater terrace area. Explosions at two vents in the N1 crater and one vent in the N2 crater in Area N were low to medium in intensity levels and ejected coarse material (bombs and lapilli) 80-150 m at a rate of 7-9 explosions per hour. Explosive activity at three active vents at the S2 sector in the Central-South area (CS) ejected coarse material generally as high as 150 m above the vent at a rate of 4-7 explosions per hour. No activity was recorded at sectors C and S1.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
Report for Suwanosejima
JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 27 March-3 April. Two eruption events on 31 March and 3 April ejected large volcanic blocks 300-400 m from the crater and the accompanying eruption plumes rose 1.7-2 km above the crater rim. Crater incandescence was visible nightly. Ashfall was reported in Toshima village (3.5 km SSW). The Alert Level was raised from 2 to 3 on 5 March and remained at 3 (on a 5-level scale) and residents were warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Ulawun
RVO reported that after a short-lived eruption at Ulawun on 28 March seismicity decreased and was characterized by very low levels of volcanic tremor at least through 31 March. In addition, small high-frequency volcanic earthquakes were recorded mainly during 29-30 March. White steam plumes of variable densities rose above the summit.
Source: Rabaul Volcano Observatory (RVO)
Report for Yasur
According to the Wellington VAAC a pilot saw an ash plume rising from Yasur to an altitude below 3 km (10,000 ft) and drifting W at 1752 on 4 April. Ash was not identified in satellite images.
Source: Wellington Volcanic Ash Advisory Center (VAAC)