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 20 October-26 October 2021
Name	Location	Eruption Start Date	Report Status
Asosan	Kyushu (Japan)	—	New
Karangetang	Sangihe Islands	2018 Nov 25	New
Kilauea	Hawaiian Islands (USA)	—	New
Krakatau	Sunda Strait	—	New
La Palma	Canary Islands	—	New
Manam	Northeast of New Guinea	2014 Jun 29	New
Yasur	Vanuatu	1270 ± 110 years	New
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Cleveland	Chuginadak Island (USA)	—	Continuing
Dukono	Halmahera	1933 Aug 13	Continuing
Ebeko	Paramushir Island (Russia)	2022 Jun 11	Continuing
Etna	Sicily (Italy)	2022 Nov 27	Continuing
Great Sitkin	Andreanof Islands (USA)	2021 May 25	Continuing
Karymsky	Eastern Kamchatka (Russia)	—	Continuing
Langila	New Britain (Papua New Guinea)	2015 Oct 22 (?)	Continuing
Lewotolok	Lembata Island	2020 Nov 27	Continuing
Merapi	Central Java	2020 Dec 31	Continuing
Pavlof	Alaska Peninsula, Alaska	—	Continuing
Semisopochnoi	Aleutian Islands (USA)	—	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Shishaldin	Fox Islands (USA)	—	Continuing

All times are local unless otherwise stated.

Asosan | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Asosan
Kyushu (Japan)

JMA characterized the eruption at Asosan that occurred at 1143 on 20 October as medium-sized. The event ejected blocks 900 m S, produced pyroclastic flows that descended 1.3 km W, and generated an ash plume that rose 3.5 km above the crater rim. Very small eruptive events were recorded during 1244-1410. The sulfur dioxide emission rate was high at 2,500 tons per day on 21 October. White plumes rose 900 m from the crater during 21-22 October. The Alert Level remained at 3 (on a scale of 1-5).

Source: Japan Meteorological Agency (JMA)

Karangetang | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Karangetang
Sangihe Islands

The Darwin VAAC reported that on 25 October a pilot observed an ash plume from Karangetang rising to 3 km (10,000 ft) a.s.l. and drifting SW. Continuous ash emissions were also visible in satellite images, though emissions ceased within five hours. The Alert Level remained at 2 (on a scale of 1-4).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Kilauea | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Kilauea
Hawaiian Islands (USA)

HVO reported that the summit eruption at Kilauea continued during 19-26 October at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a 10-m-wide breach in the E part of the W wall cone, feeding the lake which had risen 49 m since 29 September. Consistent lava fountains from the W vent rose 5-18 m with occasional bursts up to 23 m, based on field crew observations. The sulfur dioxide emission rate was high at 2,600-3,200 tonnes per day during 21-22 and 24-25 October. The lava lake was not level with the deepest parts surrounding the W vent; the W end was 8 m higher than the stagnant E part by 24 October. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Krakatau | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Krakatau
Sunda Strait

PVMBG reported that at 1413 on 26 October an eruption at Anak Krakatau produced a dense gray ash plume that rose 500 m above the summit and drifted N. The eruption lasted 45 seconds based on seismic data. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km-radius hazard zone from the crater.

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

La Palma | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

La Palma
Canary Islands

The eruption at La Palma continued during 20-26 October, characterized by Strombolian explosions, lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries issued daily. Seismicity remained elevated, with most earthquakes located 10-15 km deep (though some were as deep as 39 km); dozens of events were felt by local residents and some were felt across the entire island. A M 4.8 earthquake was recorded at 2248 on 19 October at a depth of 39 km, and the largest earthquake recorded since the beginning of the eruption, a M 4.9 at 38 km deep, was recorded at 1634 on 23 October; both of these events were felt across La Palma Island, as well as in some areas of Gomera and Tenerife islands.

The vents in the main cone continued to effuse lava, eject tephra, and produce sometimes dense and billowing ash-and-gas plumes that rose 2.8-4 km (9,200-13,100 ft) a.s.l. Sulfur dioxide emissions fluctuated at high levels between 3,200 and 53,600 tons per day. Four vents in the main cone were active, though the activity levels varied in intensity throughout the week. A new vent opened on 19 October, in an area between the 16 October vent (located 300 m from the SE base of the main cone) and the main cone. The new vent began with explosive phreatomagmatic activity before Strombolian activity commenced. The main cone changed shape, with cycles of partial crater rim and wall collapses and growth as the eruption continued. Explosions and a lava overflow from the main cone were visible at 2000 on 22 October. A partial collapse of the NW flank of the main cone on 23 October intensified ash emissions and sent large blocks downslope; the blocks fell onto another vent, causing lava to spill out into numerous lava flows. Strong explosions were heard at 1230 and lava overflowed a vent on the flanks of the main cone at 1415. On 24 October tall lava fountains rose from at least two vents. During the afternoon, a new vent opened on the W flank and effused lava at a high rate. The vent grew taller and widened during 24-25 October. The vent located at the SE end of the fissure produced slow-moving lava flows that traveled SW. Very intense explosive activity was visible on 25 October. A small collapse of the cone was observed at 1700. At around 2100 a lava lake in the main cone increased in volume, causing a partial collapse of the upper part of the cone, and producing large, detached blocks that were carried downslope by several lava flows. Lava fountains rose about 600 m above the vent.

The lava-flow field was characterized by three main areas: the initial main flow that traveled W, flowing around the S part of Montaña de Todoque, toward the sea and created a lava delta, a flow that had branched off of the main flow to the S, and the flows that traveled W along the N margins of the main flow. Lava flows sometimes overflowed their channels, forming ephemeral flows that spread laterally, descended short distances, and were also transported downslope in lava tubes. The lava flows along the northern margins (the N flow) were the most active; the flow that traveled N of Montaña Todoque had stopped, while the flow to the S of Montaña de La Laguna continued to advance and spread laterally. A lull in lava advancement during 22-23 October allowed for some homeowners to retrieve items from their residences. Lava advanced over some areas in the flow field that were previously unaffected, particularly in Alcalá, and covered an estimated 8.79 square kilometers by 26 October. The farthest end of N flows was less than 100 m from the coastline.

Lava at the delta had reached 120 m water depth and rock fragments from the end of the flow were observed at depths of 360 m. The thickness of the flow at the delta was 10-30 m; lava had filled the upper and middle parts of underwater ravines and covered an area of about 0.11 square kilometers. Scientists observed an absence of marine life around the lava flows.

Sources: Instituto Volcanológico de Canarias (INVOLCAN), Instituto Geográfico Nacional (IGN), Gobierno de Canaries

Manam | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Manam
Northeast of New Guinea

According to the Darwin VAAC, ground-based observers at Manam observed on going, low-level eruptive activity on 21 October. Ash emissions rose as high as 2.4 km (8,000 ft) a.s.l. and drifted W. Within a few hours, ash had dissipated and activity was no longer visible.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Yasur | 20 October-26 October 2021 | New Activity / Unrest Cite this Report

Yasur
Vanuatu

The Vanuatu Meteorology and Geohazards Department (VMGD) reported that seismic activity slightly increased at Yasur beginning at 1330 on 22 October. Emissions also increased and large, dense ash-and-gas plumes were visible rising from the crater in webcam images at 1445. Increased ash emissions were confirmed during field observations later that day, prompting VMGD to expand the restricted area to a 1-km radius around the cone, defined by Danger Zone B on the hazard map. The Wellington VAAC noted that ash plumes rose as high as 1.2 km (4,000 ft) a.s.l. and drifted SE, E, and N during 22-24 October, based on webcam views and information from VMGD; emissions ceased by 1845 on 24 October. The Alert Level remained at 2 (on a scale of 0-4).

Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Wellington Volcanic Ash Advisory Center (VAAC)

Aira | 20 October-26 October 2021 | Continuing ActivityCite this Report

Aira
Kyushu (Japan)

JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 18-25 October. The sulfur dioxide emission rate was 1,000 tons per day on 22 October. 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)

Cleveland | 20 October-26 October 2021 | Continuing ActivityCite this Report

Cleveland
Chuginadak Island (USA)

On 20 October AVO lowered both the Aviation Color Code and the Volcano Alert Level for Cleveland to Unassigned, noting a steady decline in volcanic unrest over the previous few months. Elevated surface temperatures were still identified in satellite images, though at a reduced frequency and strength. A short-lived explosion on 1 June 2020 was the last time eruptive activity was recorded.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Dukono | 20 October-26 October 2021 | Continuing ActivityCite this Report

Dukono
Halmahera

PVMBG reported that during 19 and 22-26 October white-and-gray ash plumes from Dukono rose as high as 300 m above the summit and drifted E and W. 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.

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

Ebeko | 20 October-26 October 2021 | Continuing ActivityCite this Report

Ebeko
Paramushir Island (Russia)

On 22 October KVERT lowered the Aviation Color Code for Ebeko to Yellow (the second lowest level on a four-color scale), noting that a thermal anomaly over the volcano was last visible on 25 August and eruptive activity had not been recorded since 22 September.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Etna | 20 October-26 October 2021 | Continuing ActivityCite this Report

Etna
Sicily (Italy)

Strombolian activity resumed at Etna’s Southeast Crater (SEC) beginning at 0447 on 20 October. Small ash-and-gas puffs drifted SW. Activity gradually increased and by 1920 on 21 October explosions were ejecting incandescent material out of the crater. Activity intensified during the evening of 22 October, and crater incandescence was visible in between weather clouds at night during 22-23 October. Ash plumes drifted NE.

Explosive Strombolian activity increased at 1000 on 23 October, producing ash plumes that then abruptly stopped at 1035. A series of strong explosions began a few minutes later, producing visible pressure waves and ash emissions. Lava fountaining began sometime before 1043 and dense ash-and-gas plumes rose several kilometers high and drifted ENE. A fracture opened on the SE side of the SEC cone and at 1048 a pyroclastic flow traveled 1.5 km SE toward the Valle del Bove. A second pyroclastic flow observed at 1100 also traveled 1.5 km SE. Several smaller pyroclastic flows were visible on the E flank of the cone. At 1158 a pyroclastic flow bifurcated and traveled a few hundred meters S and SE. Lava fountains rose as high as 800 m during the most intense period and a lava flow originating from the E side of the crater descended SE. The ash plumes rose more than 10 km (32,800 ft) a.s.l. and caused ash and lapilli to fall in many areas downwind, including Linguaglossa, Vena, Presa, Piedimonte Etneo, Taormina, and Mascali. Explosive activity began to decrease around 1200 and then ceased at 1220. Ash emissions continued to rise from the SEC and by 1932, the lava flows on the SE flank had stopped advancing.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Great Sitkin | 20 October-26 October 2021 | Continuing ActivityCite this Report

Great Sitkin
Andreanof Islands (USA)

AVO reported that lava effusion continued at Great Sitkin during 20-26 October. Lava advanced down the S and W flanks and were 500 m long by 20 October based on satellite images. Geophysical and web camera data streams returned back online during 22-23 October; seismicity remained slightly elevated and no explosive activity was recorded in both seismic and infrasound data through 26 October. Elevated surface temperatures were visible in satellite images during 25-26 October. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Karymsky | 20 October-26 October 2021 | Continuing ActivityCite this Report

Karymsky
Eastern Kamchatka (Russia)

KVERT reported that during 19-20 October explosions at Karymsky generated ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted 225 km E. A thermal anomaly was visible on 21 October. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Langila | 20 October-26 October 2021 | Continuing ActivityCite this Report

Langila
New Britain (Papua New Guinea)

The Darwin VAAC reported that on 21 October ash plumes from Langila were visible in satellite images rising 1.8-4.6 km (6,000-15,000 ft) a.s.l. and drifting NW.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Lewotolok | 20 October-26 October 2021 | Continuing ActivityCite this Report

Lewotolok
Lembata Island

PVMBG reported that the eruption at Lewotolok continued during 20-26 October. White-and-gray plumes generally rose as high as 600 m above the summit and drifted in multiple directions. 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.

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

Merapi | 20 October-26 October 2021 | Continuing ActivityCite this Report

Merapi
Central Java

BPPTKG reported no morphological changes to Merapi’s SW lava dome, located just below the SW rim and in the summit crater, and the summit crater dome during 15-21 October. Two pyroclastic flows traveled 2.5 km down the SW flank and as many as 60 lava avalanches traveled a maximum of 2 km SW. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location.

Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)

Pavlof | 20 October-26 October 2021 | Continuing ActivityCite this Report

Pavlof
Alaska Peninsula, Alaska

AVO reported that the eruption at Pavlof continued during 20-26 October and was focused at a vent on the upper SE flank, near the location of the 2007 vent. Seismicity remained elevated with tremor and daily small explosions during 20-24 October. Weather clouds obscured satellite and webcam images most days, but the explosions likely produced low-level ash plumes that rose no higher than 3 km (10,000 ft) a.s.l. Elevated surface temperatures were visible in satellite images during 25-26 October. The Volcano Alert Level and Aviation Color Code remained at Watch and Orange, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Semisopochnoi | 20 October-26 October 2021 | Continuing ActivityCite this Report

Semisopochnoi
Aleutian Islands (USA)

AVO reported that eruptive activity at Semisopochnoi's North Cerberus crater continued during 19-26 October. Tremor and multiple minor explosions were detected daily in seismic and infrasound data. Although weather clouds often prevented webcam and satellite views, intermittent, low-level ash emissions were visible during clear weather rising to altitudes up to 3 km (10,000 ft a.s.l.); the farthest plume drifted 250 km on 19 October. Sulfur dioxide emissions were detected during 25-26 October. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sheveluch | 20 October-26 October 2021 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 16-17 and 20-21 October when the volcano was visible through weather clouds. A plume of resuspended ash rose as high as 4 km (13,100 ft) a.s.l. on 21 October and drifted 40 km SE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shishaldin | 20 October-26 October 2021 | Continuing ActivityCite this Report

Shishaldin
Fox Islands (USA)

AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 20 October AVO changed both the Aviation Color Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with webcams, satellite data, remote infrasound, seismic, and GPS networks.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Weekly Reports Archive

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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.

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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 Asosan
JMA characterized the eruption at Asosan that occurred at 1143 on 20 October as medium-sized. The event ejected blocks 900 m S, produced pyroclastic flows that descended 1.3 km W, and generated an ash plume that rose 3.5 km above the crater rim. Very small eruptive events were recorded during 1244-1410. The sulfur dioxide emission rate was high at 2,500 tons per day on 21 October. White plumes rose 900 m from the crater during 21-22 October. The Alert Level remained at 3 (on a scale of 1-5).
Source: Japan Meteorological Agency (JMA)

Report for Karangetang
The Darwin VAAC reported that on 25 October a pilot observed an ash plume from Karangetang rising to 3 km (10,000 ft) a.s.l. and drifting SW. Continuous ash emissions were also visible in satellite images, though emissions ceased within five hours. The Alert Level remained at 2 (on a scale of 1-4).
Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Kilauea
HVO reported that the summit eruption at Kilauea continued during 19-26 October at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a 10-m-wide breach in the E part of the W wall cone, feeding the lake which had risen 49 m since 29 September. Consistent lava fountains from the W vent rose 5-18 m with occasional bursts up to 23 m, based on field crew observations. The sulfur dioxide emission rate was high at 2,600-3,200 tonnes per day during 21-22 and 24-25 October. The lava lake was not level with the deepest parts surrounding the W vent; the W end was 8 m higher than the stagnant E part by 24 October. 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 Krakatau
PVMBG reported that at 1413 on 26 October an eruption at Anak Krakatau produced a dense gray ash plume that rose 500 m above the summit and drifted N. The eruption lasted 45 seconds based on seismic data. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km-radius hazard zone from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for La Palma
The eruption at La Palma continued during 20-26 October, characterized by Strombolian explosions, lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries issued daily. Seismicity remained elevated, with most earthquakes located 10-15 km deep (though some were as deep as 39 km); dozens of events were felt by local residents and some were felt across the entire island. A M 4.8 earthquake was recorded at 2248 on 19 October at a depth of 39 km, and the largest earthquake recorded since the beginning of the eruption, a M 4.9 at 38 km deep, was recorded at 1634 on 23 October; both of these events were felt across La Palma Island, as well as in some areas of Gomera and Tenerife islands.

The vents in the main cone continued to effuse lava, eject tephra, and produce sometimes dense and billowing ash-and-gas plumes that rose 2.8-4 km (9,200-13,100 ft) a.s.l. Sulfur dioxide emissions fluctuated at high levels between 3,200 and 53,600 tons per day. Four vents in the main cone were active, though the activity levels varied in intensity throughout the week. A new vent opened on 19 October, in an area between the 16 October vent (located 300 m from the SE base of the main cone) and the main cone. The new vent began with explosive phreatomagmatic activity before Strombolian activity commenced. The main cone changed shape, with cycles of partial crater rim and wall collapses and growth as the eruption continued. Explosions and a lava overflow from the main cone were visible at 2000 on 22 October. A partial collapse of the NW flank of the main cone on 23 October intensified ash emissions and sent large blocks downslope; the blocks fell onto another vent, causing lava to spill out into numerous lava flows. Strong explosions were heard at 1230 and lava overflowed a vent on the flanks of the main cone at 1415. On 24 October tall lava fountains rose from at least two vents. During the afternoon, a new vent opened on the W flank and effused lava at a high rate. The vent grew taller and widened during 24-25 October. The vent located at the SE end of the fissure produced slow-moving lava flows that traveled SW. Very intense explosive activity was visible on 25 October. A small collapse of the cone was observed at 1700. At around 2100 a lava lake in the main cone increased in volume, causing a partial collapse of the upper part of the cone, and producing large, detached blocks that were carried downslope by several lava flows. Lava fountains rose about 600 m above the vent.

The lava-flow field was characterized by three main areas: the initial main flow that traveled W, flowing around the S part of Montaña de Todoque, toward the sea and created a lava delta, a flow that had branched off of the main flow to the S, and the flows that traveled W along the N margins of the main flow. Lava flows sometimes overflowed their channels, forming ephemeral flows that spread laterally, descended short distances, and were also transported downslope in lava tubes. The lava flows along the northern margins (the N flow) were the most active; the flow that traveled N of Montaña Todoque had stopped, while the flow to the S of Montaña de La Laguna continued to advance and spread laterally. A lull in lava advancement during 22-23 October allowed for some homeowners to retrieve items from their residences. Lava advanced over some areas in the flow field that were previously unaffected, particularly in Alcalá, and covered an estimated 8.79 square kilometers by 26 October. The farthest end of N flows was less than 100 m from the coastline.

Lava at the delta had reached 120 m water depth and rock fragments from the end of the flow were observed at depths of 360 m. The thickness of the flow at the delta was 10-30 m; lava had filled the upper and middle parts of underwater ravines and covered an area of about 0.11 square kilometers. Scientists observed an absence of marine life around the lava flows.
Sources: Instituto Volcanológico de Canarias (INVOLCAN), Instituto Geográfico Nacional (IGN), Gobierno de Canaries

Report for Manam
According to the Darwin VAAC, ground-based observers at Manam observed on going, low-level eruptive activity on 21 October. Ash emissions rose as high as 2.4 km (8,000 ft) a.s.l. and drifted W. Within a few hours, ash had dissipated and activity was no longer visible.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Yasur
The Vanuatu Meteorology and Geohazards Department (VMGD) reported that seismic activity slightly increased at Yasur beginning at 1330 on 22 October. Emissions also increased and large, dense ash-and-gas plumes were visible rising from the crater in webcam images at 1445. Increased ash emissions were confirmed during field observations later that day, prompting VMGD to expand the restricted area to a 1-km radius around the cone, defined by Danger Zone B on the hazard map. The Wellington VAAC noted that ash plumes rose as high as 1.2 km (4,000 ft) a.s.l. and drifted SE, E, and N during 22-24 October, based on webcam views and information from VMGD; emissions ceased by 1845 on 24 October. The Alert Level remained at 2 (on a scale of 0-4).
Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Wellington Volcanic Ash Advisory Center (VAAC)

Report for Aira
JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 18-25 October. The sulfur dioxide emission rate was 1,000 tons per day on 22 October. 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 Cleveland
On 20 October AVO lowered both the Aviation Color Code and the Volcano Alert Level for Cleveland to Unassigned, noting a steady decline in volcanic unrest over the previous few months. Elevated surface temperatures were still identified in satellite images, though at a reduced frequency and strength. A short-lived explosion on 1 June 2020 was the last time eruptive activity was recorded.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Dukono
PVMBG reported that during 19 and 22-26 October white-and-gray ash plumes from Dukono rose as high as 300 m above the summit and drifted E and W. 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.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Ebeko
On 22 October KVERT lowered the Aviation Color Code for Ebeko to Yellow (the second lowest level on a four-color scale), noting that a thermal anomaly over the volcano was last visible on 25 August and eruptive activity had not been recorded since 22 September.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Etna
Strombolian activity resumed at Etna’s Southeast Crater (SEC) beginning at 0447 on 20 October. Small ash-and-gas puffs drifted SW. Activity gradually increased and by 1920 on 21 October explosions were ejecting incandescent material out of the crater. Activity intensified during the evening of 22 October, and crater incandescence was visible in between weather clouds at night during 22-23 October. Ash plumes drifted NE.

Explosive Strombolian activity increased at 1000 on 23 October, producing ash plumes that then abruptly stopped at 1035. A series of strong explosions began a few minutes later, producing visible pressure waves and ash emissions. Lava fountaining began sometime before 1043 and dense ash-and-gas plumes rose several kilometers high and drifted ENE. A fracture opened on the SE side of the SEC cone and at 1048 a pyroclastic flow traveled 1.5 km SE toward the Valle del Bove. A second pyroclastic flow observed at 1100 also traveled 1.5 km SE. Several smaller pyroclastic flows were visible on the E flank of the cone. At 1158 a pyroclastic flow bifurcated and traveled a few hundred meters S and SE. Lava fountains rose as high as 800 m during the most intense period and a lava flow originating from the E side of the crater descended SE. The ash plumes rose more than 10 km (32,800 ft) a.s.l. and caused ash and lapilli to fall in many areas downwind, including Linguaglossa, Vena, Presa, Piedimonte Etneo, Taormina, and Mascali. Explosive activity began to decrease around 1200 and then ceased at 1220. Ash emissions continued to rise from the SEC and by 1932, the lava flows on the SE flank had stopped advancing.
Source: Sezione di Catania - Osservatorio Etneo (INGV)

Report for Great Sitkin
AVO reported that lava effusion continued at Great Sitkin during 20-26 October. Lava advanced down the S and W flanks and were 500 m long by 20 October based on satellite images. Geophysical and web camera data streams returned back online during 22-23 October; seismicity remained slightly elevated and no explosive activity was recorded in both seismic and infrasound data through 26 October. Elevated surface temperatures were visible in satellite images during 25-26 October. 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 Karymsky
KVERT reported that during 19-20 October explosions at Karymsky generated ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted 225 km E. A thermal anomaly was visible on 21 October. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Langila
The Darwin VAAC reported that on 21 October ash plumes from Langila were visible in satellite images rising 1.8-4.6 km (6,000-15,000 ft) a.s.l. and drifting NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 20-26 October. White-and-gray plumes generally rose as high as 600 m above the summit and drifted in multiple directions. 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.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Merapi
BPPTKG reported no morphological changes to Merapi’s SW lava dome, located just below the SW rim and in the summit crater, and the summit crater dome during 15-21 October. Two pyroclastic flows traveled 2.5 km down the SW flank and as many as 60 lava avalanches traveled a maximum of 2 km SW. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 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 Pavlof continued during 20-26 October and was focused at a vent on the upper SE flank, near the location of the 2007 vent. Seismicity remained elevated with tremor and daily small explosions during 20-24 October. Weather clouds obscured satellite and webcam images most days, but the explosions likely produced low-level ash plumes that rose no higher than 3 km (10,000 ft) a.s.l. Elevated surface temperatures were visible in satellite images during 25-26 October. The Volcano Alert Level and Aviation Color Code remained at Watch and Orange, respectively.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Semisopochnoi
AVO reported that eruptive activity at Semisopochnoi's North Cerberus crater continued during 19-26 October. Tremor and multiple minor explosions were detected daily in seismic and infrasound data. Although weather clouds often prevented webcam and satellite views, intermittent, low-level ash emissions were visible during clear weather rising to altitudes up to 3 km (10,000 ft a.s.l.); the farthest plume drifted 250 km on 19 October. Sulfur dioxide emissions were detected during 25-26 October. 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 16-17 and 20-21 October when the volcano was visible through weather clouds. A plume of resuspended ash rose as high as 4 km (13,100 ft) a.s.l. on 21 October and drifted 40 km SE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Shishaldin
AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 20 October AVO changed both the Aviation Color Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with webcams, satellite data, remote infrasound, seismic, and GPS networks.
Source: US Geological Survey Alaska Volcano Observatory (AVO)