Smithsonian / USGS Weekly Volcanic Activity Report

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 13 April-19 April 2022
Name	Location	Eruption Start Date	Report Status
Bezymianny	Central Kamchatka (Russia)	2016 Dec 5	New
Edgecumbe	Southeastern Alaska (USA)	—	New
Karymsky	Eastern Kamchatka (Russia)	—	New
Krakatau	Sunda Strait	—	New
Poas	Costa Rica	2023 Dec 1	New
Ruang	Sangihe Islands	—	New
Ruapehu	North Island (New Zealand)	—	New
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Asosan	Kyushu (Japan)	—	Continuing
Dukono	Halmahera	1933 Aug 13	Continuing
Great Sitkin	Andreanof Islands (USA)	2021 May 25	Continuing
Kilauea	Hawaiian Islands (USA)	—	Continuing
Lewotolok	Lembata Island	2020 Nov 27	Continuing
Manam	Northeast of New Guinea	2014 Jun 29	Continuing
Merapi	Central Java	2020 Dec 31	Continuing
Pavlof	Alaska Peninsula, Alaska	—	Continuing
Reventador	Ecuador	2008 Jul 27	Continuing
Sangay	Ecuador	2019 Mar 26	Continuing
Semeru	Eastern Java	2017 Jun 6	Continuing
Semisopochnoi	Aleutian Islands (USA)	—	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Suwanosejima	Ryukyu Islands (Japan)	2004 Oct 23	Continuing
Wolf	Isla Isabela (Galapagos)	—	Continuing

All times are local unless otherwise stated.

Bezymianny | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Bezymianny
Central Kamchatka (Russia)

KVERT reported that the effusive eruption at Bezymianny continued during 8-15 April, along with incandescence at the lava dome, avalanches descending the SE flank, and steam-and-ash emissions. A daily thermal anomaly over the dome was identified in satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS)

Edgecumbe | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Edgecumbe
Southeastern Alaska (USA)

AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe began at about 0200 on 11 April, and by 15 April several hundred earthquakes had been recorded. The number of events was unusual for that volcano. The magnitudes were generally M 1.7 or smaller, though a M 2.8 was detected on 11 April. The events were located at depths of less than 10 km, though the exact locations were difficult to constrain due to the lack of a local seismic network on the island; the closest station was in Sitka, 25 km E. The source of the swarm was unknown, and related either to tectonic processes or volcanic unrest, or a combination of both. Both the Volcano Alert Level and Aviation Color Code were Unassigned due to the lack of dedicated, local instrumentation. AVO noted that additional data from distant seismic stations was being analyzed, and several years of Synthetic Aperture Radar (SAR) data was being evaluated for topographical changes. No surficial changes were visible in recent satellite images and webcams views.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Karymsky | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Karymsky
Eastern Kamchatka (Russia)

KVERT reported that a thermal anomaly over Karymsky was visible in satellite images on 9 and 11-12 April; the volcano was quiet or obscured by clouds on the other days during 8-15 April. Explosions produced ash plumes that rose to 6 km (19,700 ft) a.s.l. and drifted SSW, based on satellite data acquired at 0810 on 20 April, local time. Explosions continued and within an hour produced larger ash plumes that rose 9.8-10 km (32,100-32,800 ft) a.s.l. and drifted almost 30 km NE. KVERT raised the Aviation Color Code to Red (the 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)

Krakatau | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Krakatau
Sunda Strait

PVMBG reported that several ash emissions from Anak Krakatau were visible in webcam images and described by observers during 15 and 17-19 April. The ash plumes were variably whitish gray, gray, and black, with all but one characterized as dense. Events at 0327, 1034, and 1837 on 15 April produced ash plumes that rose 0.7-1 km above the summit and drifted SW. Ash plumes at 0925, 1830, and 2215 on 17 April rose 500-800 m above the summit and drifted SW; Strombolian activity produced the ash plume at 1830. On 18 April events at 0358, 0419, 0714, 1246, 1330, and 1558 generated ash plumes that rose as high as 2 km and drifted SW. Ash plumes were visible on 19 April, rising 50-500 m above the summit and drifting SE and NE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Poas | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Poas
Costa Rica

OVSICORI-UNA reported that submarine fumaroles in the S part of Poás’s Boca A lake and subaerial fumaroles along the E margins continued to produce low-temperature gas emissions during 13-19 April. The lake water continued to convect, and was light gray in color, since the phreatic explosion that had occurred on 6 April at “Orange Fumarola” located in a fumarolic field along the inner N crater wall. For a period of time on 17 April a gas monitoring station in Coronado measured a higher concentration of sulfur dioxide aerosols, between 8.5 and 17.6 micrograms of gas per cubic meter of ambient air, which was higher than the daily average of 6.7. Some residents reported respiratory discomfort such as sneezing, coughing, and shortness of breath.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Ruang | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Ruang
Sangihe Islands

PVMBG reported that at least 121 deep volcanic earthquakes at Ruang were recorded during 1-16 April, though the number of those events began to increase on 7 April. No visible changes to the crater were noted, but weather conditions sometimes prevented views. Seismicity significantly changed on 16 April, characterized by 50 deep volcanic earthquakes, two local tectonic earthquakes, and four felt earthquakes. That same day the Alert Level was raised to 2 (on a scale of 1-4) and residents and tourists were warned to stay 1.5 km away from the active craters and 2.5 km on the E, SE, S, and SW flanks. Elevated seismicity continued to be recorded through 18 April.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Ruapehu | 13 April-19 April 2022 | New Activity / Unrest Cite this Report

Ruapehu
North Island (New Zealand)

On 20 April GeoNet reported that elevated unrest at Ruapehu had continued during the previous week. Scientists observed upwelling in the lake over the N vent area and visible sulfur slicks on the lake’s surface during an observation flight. The lake water temperature had stabilized at 37 degrees Celsius and continued to be medium gray in color. The lake observations were within normal ranges for a typical heating cycle. Tremor levels remain elevated, though, representing the longest period of tremor recorded over the previous 20 years. The Volcanic Alert Level remained at 2 (on a scale from 0-5) and the Aviation Color Code remained at Yellow.

Source: GeoNet

Aira | 13 April-19 April 2022 | Continuing ActivityCite this Report

Aira
Kyushu (Japan)

JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 11-18 April. Crater incandescence was periodically visible at night. The Alert Level 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)

Asosan | 13 April-19 April 2022 | Continuing ActivityCite this Report

Asosan
Kyushu (Japan)

JMA reported that no eruptions had been recorded at Asosan after the end of the last eruption in October 2021. Crater incandescence, which had been occasionally visible since December 2021, was absent beginning on 27 February. Deflation began around 27 February but stabilized in April. Observations of the crater from 17 March revealed that it had deepened, compared to pre-eruption conditions, and that water had returned. Sulfur dioxide emissions had increased to 1,600 tons per day on 25 March, but four observations made during 29 March-12 April showed values in the range of 800-1,200 tons per day. Though these values were higher than those measured in September 2021, before the eruption, they represented a decreasing trend. During a field visit on 7 April scientists observed white emissions rising from Nakadake Crater and gray pools of hot water on the crater floor. A hot spring was active on the S side of the pools. The area of the water represented about 40 percent of the crater floor and the water temperature was 71 degrees Celsius. JMA lowered the Alert Level to 1 (on a scale of 1-5) on 15 April, noting that the likelihood of an eruption affecting an area within a radius of 1 km had decreased.

Source: Japan Meteorological Agency (JMA)

Dukono | 13 April-19 April 2022 | Continuing ActivityCite this Report

Dukono
Halmahera

Based on satellite and wind model data, the Darwin VAAC reported that during 13-18 April ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NE, E, SE, and S. 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)

Great Sitkin | 13 April-19 April 2022 | Continuing ActivityCite this Report

Great Sitkin
Andreanof Islands (USA)

AVO reported that slow lava effusion at Great Sitkin continued during 13-19 April, based on high-resolution satellite data. Weather clouds prevented visual observations on most days. Very low seismicity persisted. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Kilauea | 13 April-19 April 2022 | Continuing ActivityCite this Report

Kilauea
Hawaiian Islands (USA)

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 12-19 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Flows occasionally overtopped perched levees. At 2315 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins, and was active through 14 April. Breakouts along the N, NE, and S parts of the crater were visible during 14-19 April. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Lewotolok | 13 April-19 April 2022 | Continuing ActivityCite this Report

Lewotolok
Lembata Island

PVMBG reported that the eruption at Lewotolok continued during 12-19 April. Daily white-and-gray ash plumes rose as high as 50-500 m above the summit and drifted W, NW, and E. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater and 4 km away from the crater on the SE flank.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Manam | 13 April-19 April 2022 | Continuing ActivityCite this Report

Manam
Northeast of New Guinea

The Darwin VAAC reported that on 18 April ash plumes from Manam rose to 13.7 km (45,000 ft) a.s.l. and drifted N based on information from RVO, satellite images, and weather models. Ash had dissipated by 1540. At 2000 an ash plume was visible in a satellite image through a break in weather cloud cover drifted NE at an altitude of 4.9 km (16,000 ft) a.s.l. Ash had dissipated by 0830 on 19 April.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Merapi | 13 April-19 April 2022 | Continuing ActivityCite this Report

Merapi
Central Java

BPPTKG reported that the eruption at Merapi continued during 8-14 April. The volumes of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 112 lava avalanches originating from two areas on the SW dome traveled a maximum of 2 km down the Bebeng drainage on the SW flank. 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)

Pavlof | 13 April-19 April 2022 | Continuing ActivityCite this Report

Pavlof
Alaska Peninsula, Alaska

AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 12-19 April, though weather conditions sometimes prevented visual observations. Seismic tremor persisted and elevated surface temperatures were identified in satellite images almost daily. Steam emissions were seen rising above the summit in webcam images on 16 April. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Reventador | 13 April-19 April 2022 | Continuing ActivityCite this Report

Reventador
Ecuador

IG staff observed high levels of activity at Reventador during a field visit from 4 to 7 April, and noted sporadic emissions with moderate ash content. They viewed the volcano with a thermal camera and saw an active lava flow on the upper NNE flank, producing rock avalanches as it advanced. The flow was 1.7-2 km long and effused from a vent about 200 m below the summit on the NNE flank. Two inactive and cooling flows were located adjacent to the active flow. Activity continued to be high during 12-19 April, though cloudy weather conditions frequently prevented visual observations. Steam, gas, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1 km above the summit crater and drifted W and NW. Crater incandescence was visible most nights and early mornings; incandescent material was visible descending the flanks during 13-14 April.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Sangay | 13 April-19 April 2022 | Continuing ActivityCite this Report

Sangay
Ecuador

IG reported that the eruption at Sangay continued at a high level, with lava flows effusing from the Ñuñurcu, Central, and Norte vents. Explosions originated from a western vent that reactivated in late 2021, and from Central vent. The Norte vent, on the N flank, had opened on 2 December 2021. Activity levels were slightly higher during 4-6 April, characterized by a higher rate of lava effusion and a satellite-detected thermal anomaly at the Norte vent on 4 April, along with a diffuse but continuously-emitted volcanic cloud that rose 1.7 km above the crater rim and drifted up to 650 km W during 5-6 April. Low-frequency tremor was also recorded during 5-6 April. Even though the eruption plume drifted notably farther than average distances recorded during 2019-2022, only minor ashfall was reported in Chauzán San Alfonso (40 km W, in Guamote canton, Chimborazo province). During 12-18 April weather clouds and rain often prevented visual and webcam observations of the volcano, though daily ash-and-gas plumes were identified in satellite images by the Washington VAAC or in webcam views; plumes rose less than 2 km above the volcano and drifted W and NW. Minor ashfall was reported in Chauzán San Alfonso. The seismic network detected signals indicating descending lahars during 12-13 and 15 April.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Semeru | 13 April-19 April 2022 | Continuing ActivityCite this Report

Semeru
Eastern Java

PVMBG reported that the eruption at Semeru continued during 13-19 April. Daily ash plumes were visible rising 300-400 m above the summit and drifted N and S, even though cloudy weather sometimes prevented visual observations. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with 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)

Semisopochnoi | 13 April-19 April 2022 | Continuing ActivityCite this Report

Semisopochnoi
Aleutian Islands (USA)

AVO reported that low-level eruptive activity at Semisopochnoi's North Cerberus cone continued during 12-19 April. Periods of seismic tremor were detected daily and occasional small explosions were recorded in seismic and regional infrasound data on most days. Weather cloud cover often hindered webcam and satellite views; minor, low-level ash plumes were visible in webcam images during 16-19 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sheveluch | 13 April-19 April 2022 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 8-15 April, and lava-dome extrusion continued. Explosions on 9 April produced ash plumes that rose as high as 12 km (39,400 ft) a.s.l. and drifted more than 2,000 km NE during 9-10 April. Explosions during 13-14 April generated ash plumes that rose to 6-6.5 km (19,700-21,300 ft) a.s.l. and drifted 80-110 km SW and S. 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)

Suwanosejima | 13 April-19 April 2022 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Islands (Japan)

JMA reported that eruptive activity continued to be recorded at Suwanosejima's Ontake Crater during 11-18 April. One explosion produced an eruption plume that rose as high as 2.7 km above the crater rim. Ashfall was reported in Toshima village (3.5 km SSW) and in other areas as far as 5 km away. No explosions were recorded during 15-18 April, though emissions rose 1.1 km. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Wolf | 13 April-19 April 2022 | Continuing ActivityCite this Report

Wolf
Isla Isabela (Galapagos)

IG reported that the eruption at Wolf continued during 13-18 April. Lava flows continued to advance towards the coast based on thermal data; satellite images showed minor advancement during 11-16 April and the end of the flow near the coastline.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Sentinel Hub

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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.

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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.

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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 Bezymianny
KVERT reported that the effusive eruption at Bezymianny continued during 8-15 April, along with incandescence at the lava dome, avalanches descending the SE flank, and steam-and-ash emissions. A daily thermal anomaly over the dome was identified in satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS)

Report for Edgecumbe
AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe began at about 0200 on 11 April, and by 15 April several hundred earthquakes had been recorded. The number of events was unusual for that volcano. The magnitudes were generally M 1.7 or smaller, though a M 2.8 was detected on 11 April. The events were located at depths of less than 10 km, though the exact locations were difficult to constrain due to the lack of a local seismic network on the island; the closest station was in Sitka, 25 km E. The source of the swarm was unknown, and related either to tectonic processes or volcanic unrest, or a combination of both. Both the Volcano Alert Level and Aviation Color Code were Unassigned due to the lack of dedicated, local instrumentation. AVO noted that additional data from distant seismic stations was being analyzed, and several years of Synthetic Aperture Radar (SAR) data was being evaluated for topographical changes. No surficial changes were visible in recent satellite images and webcams views.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Karymsky
KVERT reported that a thermal anomaly over Karymsky was visible in satellite images on 9 and 11-12 April; the volcano was quiet or obscured by clouds on the other days during 8-15 April. Explosions produced ash plumes that rose to 6 km (19,700 ft) a.s.l. and drifted SSW, based on satellite data acquired at 0810 on 20 April, local time. Explosions continued and within an hour produced larger ash plumes that rose 9.8-10 km (32,100-32,800 ft) a.s.l. and drifted almost 30 km NE. KVERT raised the Aviation Color Code to Red (the 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 Krakatau
PVMBG reported that several ash emissions from Anak Krakatau were visible in webcam images and described by observers during 15 and 17-19 April. The ash plumes were variably whitish gray, gray, and black, with all but one characterized as dense. Events at 0327, 1034, and 1837 on 15 April produced ash plumes that rose 0.7-1 km above the summit and drifted SW. Ash plumes at 0925, 1830, and 2215 on 17 April rose 500-800 m above the summit and drifted SW; Strombolian activity produced the ash plume at 1830. On 18 April events at 0358, 0419, 0714, 1246, 1330, and 1558 generated ash plumes that rose as high as 2 km and drifted SW. Ash plumes were visible on 19 April, rising 50-500 m above the summit and drifting SE and NE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Poas
OVSICORI-UNA reported that submarine fumaroles in the S part of Poás’s Boca A lake and subaerial fumaroles along the E margins continued to produce low-temperature gas emissions during 13-19 April. The lake water continued to convect, and was light gray in color, since the phreatic explosion that had occurred on 6 April at “Orange Fumarola” located in a fumarolic field along the inner N crater wall. For a period of time on 17 April a gas monitoring station in Coronado measured a higher concentration of sulfur dioxide aerosols, between 8.5 and 17.6 micrograms of gas per cubic meter of ambient air, which was higher than the daily average of 6.7. Some residents reported respiratory discomfort such as sneezing, coughing, and shortness of breath.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Report for Ruang
PVMBG reported that at least 121 deep volcanic earthquakes at Ruang were recorded during 1-16 April, though the number of those events began to increase on 7 April. No visible changes to the crater were noted, but weather conditions sometimes prevented views. Seismicity significantly changed on 16 April, characterized by 50 deep volcanic earthquakes, two local tectonic earthquakes, and four felt earthquakes. That same day the Alert Level was raised to 2 (on a scale of 1-4) and residents and tourists were warned to stay 1.5 km away from the active craters and 2.5 km on the E, SE, S, and SW flanks. Elevated seismicity continued to be recorded through 18 April.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Ruapehu
On 20 April GeoNet reported that elevated unrest at Ruapehu had continued during the previous week. Scientists observed upwelling in the lake over the N vent area and visible sulfur slicks on the lake’s surface during an observation flight. The lake water temperature had stabilized at 37 degrees Celsius and continued to be medium gray in color. The lake observations were within normal ranges for a typical heating cycle. Tremor levels remain elevated, though, representing the longest period of tremor recorded over the previous 20 years. The Volcanic Alert Level remained at 2 (on a scale from 0-5) and the Aviation Color Code remained at Yellow.
Source: GeoNet

Report for Aira
JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 11-18 April. Crater incandescence was periodically visible at night. The Alert Level 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 Asosan
JMA reported that no eruptions had been recorded at Asosan after the end of the last eruption in October 2021. Crater incandescence, which had been occasionally visible since December 2021, was absent beginning on 27 February. Deflation began around 27 February but stabilized in April. Observations of the crater from 17 March revealed that it had deepened, compared to pre-eruption conditions, and that water had returned. Sulfur dioxide emissions had increased to 1,600 tons per day on 25 March, but four observations made during 29 March-12 April showed values in the range of 800-1,200 tons per day. Though these values were higher than those measured in September 2021, before the eruption, they represented a decreasing trend. During a field visit on 7 April scientists observed white emissions rising from Nakadake Crater and gray pools of hot water on the crater floor. A hot spring was active on the S side of the pools. The area of the water represented about 40 percent of the crater floor and the water temperature was 71 degrees Celsius. JMA lowered the Alert Level to 1 (on a scale of 1-5) on 15 April, noting that the likelihood of an eruption affecting an area within a radius of 1 km had decreased.
Source: Japan Meteorological Agency (JMA)

Report for Dukono
Based on satellite and wind model data, the Darwin VAAC reported that during 13-18 April ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NE, E, SE, and S. 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)

Report for Great Sitkin
AVO reported that slow lava effusion at Great Sitkin continued during 13-19 April, based on high-resolution satellite data. Weather clouds prevented visual observations on most days. Very low seismicity persisted. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Kilauea
HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 12-19 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Flows occasionally overtopped perched levees. At 2315 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins, and was active through 14 April. Breakouts along the N, NE, and S parts of the crater were visible during 14-19 April. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 12-19 April. Daily white-and-gray ash plumes rose as high as 50-500 m above the summit and drifted W, NW, and E. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater and 4 km away from the crater on the SE flank.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Manam
The Darwin VAAC reported that on 18 April ash plumes from Manam rose to 13.7 km (45,000 ft) a.s.l. and drifted N based on information from RVO, satellite images, and weather models. Ash had dissipated by 1540. At 2000 an ash plume was visible in a satellite image through a break in weather cloud cover drifted NE at an altitude of 4.9 km (16,000 ft) a.s.l. Ash had dissipated by 0830 on 19 April.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Merapi
BPPTKG reported that the eruption at Merapi continued during 8-14 April. The volumes of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 112 lava avalanches originating from two areas on the SW dome traveled a maximum of 2 km down the Bebeng drainage on the SW flank. 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 Pavlof
AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 12-19 April, though weather conditions sometimes prevented visual observations. Seismic tremor persisted and elevated surface temperatures were identified in satellite images almost daily. Steam emissions were seen rising above the summit in webcam images on 16 April. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Reventador
IG staff observed high levels of activity at Reventador during a field visit from 4 to 7 April, and noted sporadic emissions with moderate ash content. They viewed the volcano with a thermal camera and saw an active lava flow on the upper NNE flank, producing rock avalanches as it advanced. The flow was 1.7-2 km long and effused from a vent about 200 m below the summit on the NNE flank. Two inactive and cooling flows were located adjacent to the active flow. Activity continued to be high during 12-19 April, though cloudy weather conditions frequently prevented visual observations. Steam, gas, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1 km above the summit crater and drifted W and NW. Crater incandescence was visible most nights and early mornings; incandescent material was visible descending the flanks during 13-14 April.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Report for Sangay
IG reported that the eruption at Sangay continued at a high level, with lava flows effusing from the Ñuñurcu, Central, and Norte vents. Explosions originated from a western vent that reactivated in late 2021, and from Central vent. The Norte vent, on the N flank, had opened on 2 December 2021. Activity levels were slightly higher during 4-6 April, characterized by a higher rate of lava effusion and a satellite-detected thermal anomaly at the Norte vent on 4 April, along with a diffuse but continuously-emitted volcanic cloud that rose 1.7 km above the crater rim and drifted up to 650 km W during 5-6 April. Low-frequency tremor was also recorded during 5-6 April. Even though the eruption plume drifted notably farther than average distances recorded during 2019-2022, only minor ashfall was reported in Chauzán San Alfonso (40 km W, in Guamote canton, Chimborazo province). During 12-18 April weather clouds and rain often prevented visual and webcam observations of the volcano, though daily ash-and-gas plumes were identified in satellite images by the Washington VAAC or in webcam views; plumes rose less than 2 km above the volcano and drifted W and NW. Minor ashfall was reported in Chauzán San Alfonso. The seismic network detected signals indicating descending lahars during 12-13 and 15 April.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Report for Semeru
PVMBG reported that the eruption at Semeru continued during 13-19 April. Daily ash plumes were visible rising 300-400 m above the summit and drifted N and S, even though cloudy weather sometimes prevented visual observations. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with 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 eruptive activity at Semisopochnoi's North Cerberus cone continued during 12-19 April. Periods of seismic tremor were detected daily and occasional small explosions were recorded in seismic and regional infrasound data on most days. Weather cloud cover often hindered webcam and satellite views; minor, low-level ash plumes were visible in webcam images during 16-19 April. 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 Sheveluch
KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 8-15 April, and lava-dome extrusion continued. Explosions on 9 April produced ash plumes that rose as high as 12 km (39,400 ft) a.s.l. and drifted more than 2,000 km NE during 9-10 April. Explosions during 13-14 April generated ash plumes that rose to 6-6.5 km (19,700-21,300 ft) a.s.l. and drifted 80-110 km SW and S. 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 Suwanosejima
JMA reported that eruptive activity continued to be recorded at Suwanosejima's Ontake Crater during 11-18 April. One explosion produced an eruption plume that rose as high as 2.7 km above the crater rim. Ashfall was reported in Toshima village (3.5 km SSW) and in other areas as far as 5 km away. No explosions were recorded during 15-18 April, though emissions rose 1.1 km. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)

Report for Wolf
IG reported that the eruption at Wolf continued during 13-18 April. Lava flows continued to advance towards the coast based on thermal data; satellite images showed minor advancement during 11-16 April and the end of the flow near the coastline.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Sentinel Hub