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 28 September-4 October 2022
Name	Country	Volcanic Province	Eruption Start Date	Report Status
Alaid	Russia	Kuril Volcanic Arc	—	New
Home Reef	Tonga	Tofua Volcanic Arc	—	New
Nishinoshima	Japan	Ogasawara Volcanic Arc	—	New
Piton de la Fournaise	France	Reunion Hotspot Volcano Group	—	New
Trident	United States	Alaska Peninsula Volcanic Arc	—	New
Aira	Japan	Ryukyu Volcanic Arc	2017 Mar 25	Continuing
Ebeko	Russia	Kuril Volcanic Arc	2022 Jun 11	Continuing
Great Sitkin	United States	Aleutian Ridge Volcanic Arc	2021 May 25	Continuing
Karthala	Comoros	Comoros Hotspot Volcano Group	—	Continuing
Kilauea	United States	Hawaiian-Emperor Hotspot Volcano Group	—	Continuing
Lewotolok	Indonesia	Sunda Volcanic Arc	2020 Nov 27	Continuing
Marapi	Indonesia	Sunda Volcanic Arc	2023 Dec 3	Continuing
Merapi	Indonesia	Sunda Volcanic Arc	2020 Dec 31	Continuing
Nevados de Chillan	Chile	Andean Southern Volcanic Arc	—	Continuing
Pavlof	United States	Aleutian Ridge Volcanic Arc	—	Continuing
Sabancaya	Peru	Andean Central Volcanic Arc	2016 Nov 6	Continuing
Semeru	Indonesia	Sunda Volcanic Arc	2017 Jun 6	Continuing
Semisopochnoi	United States	Aleutian Ridge Volcanic Arc	—	Continuing
Sheveluch	Russia	Eastern Kamchatka Volcanic Arc	1999 Aug 15	Continuing
Stromboli	Italy	Aeolian Volcanic Arc	1934 Feb 2	Continuing
Suwanosejima	Japan	Ryukyu Volcanic Arc	2004 Oct 23	Continuing
Taal	Philippines	Taiwan-Luzon Volcanic Arc	2024 Apr 12	Continuing
Ta'u	United States	Samoan Hotspot Volcano Group	—	Continuing
Villarrica	Chile	Andean Southern Volcanic Arc	2014 Dec 2 ± 7 days	Continuing
Whakaari/White Island	New Zealand	Taupo Volcanic Zone	—	Continuing

All times are local unless otherwise stated.

Alaid (Russia) | 28 September-4 October 2022 | New Activity / Unrest Cite this Report

Alaid
Kuril Volcanic Arc

KVERT reported that a thermal anomaly over Alaid was identified in satellite images during 22-30 September. Ash plumes were visible drifting 140 km NE and SE during 26-27 September. 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)

Home Reef (Tonga) | 28 September-4 October 2022 | New Activity / Unrest Cite this Report

Home Reef
Tofua Volcanic Arc

The Tonga Geological Services reported that the new island at Home Reef that emerged from the ocean on 10 September continued to grow through 4 October. Daily counts of eruptive events producing gas-and-steam plumes were variable, though during the middle of the week they had decreased to less than 10 events per day. By 1040 on 28 September the dimensions of the new island were estimated to be 268 m N-S and 283 m E-W, and the highest point on the island was about 15 m a.s.l. The island was surrounded by plumes of discolored water within about 200 m from the shore. The plumes were elongated to the S, and were denser with suspended material within 1 km and more diffuse at distances greater or equal to 2 km. Mariners were advised to stay 4 km away from the volcano.

Source: Tonga Geological Services, Government of Tonga

Nishinoshima (Japan) | 28 September-4 October 2022 | New Activity / Unrest Cite this Report

Nishinoshima
Ogasawara Volcanic Arc

According to JMA and the Tokyo VAAC an eruption at Nishinoshima produced ash plumes that rose to 1.8-2.6 km (6,000-8,500 ft) a.s.l. and drifted E and W during 1-4 October.

Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)

Piton de la Fournaise (France) | 28 September-4 October 2022 | New Activity / Unrest Cite this Report

Piton de la Fournaise
Reunion Hotspot Volcano Group

OVPF reported that the eruption at Piton de la Fournaise that began on 19 September was ongoing at a cone adjacent to the SW flank of Piton Kala Pélé during 28 September-4 October. The cone ejected lava to low heights above the rim. Lava flowed from the base of the cone in two main branches, to the SE and E, mainly through lava tubes, as far as 3 km. By 28 September the cone had grown to just over 8 m tall and around 27 m wide at its base. Average daily lava flow discharge rate estimates had a mean value of 8 meters per second at the beginning of the eruption but then stabilized at 2-4 meters per second; the flow rate increased during 28-29 September to more than 6 meters per second. Lava discharge rates were likely underestimated due to measurements hindered by weather conditions or flows obscured by tubes. Tremor levels and gas emissions also began increasing on 29 September and remained at high levels during the rest of the week. The vent at the top of the cone widened and a new, smaller cone formed on the S flank and produced lava flows. The volume of erupted lava was 2.6-5.4 million cubic meters by 30 September; peak discharge rates reached 20 meters per second at times.

Sulfur dioxide emission estimates derived from satellite data had increased from about 610 tons per day on 28 September to 1,525 tons per day on 1 October. A well-defined gas plume, denser than those seen during previous days, was identified in a 30 September satellite image drifting 300 km NW at an altitude of 3 km (10,000 ft) a.s.l. A more significant sulfur dioxide plume was identified in satellite data the next day, drifting as far as 400 km. Gas plumes drifted SW during 2-3 October. Sulfur dioxide emissions continued to increase and were about 2,500 tons per day on 3 October. The cone had grown to around 12 m tall and 43 m wide at the base.

During 3-4 October the ejection of lava above the cone became less intense, and the new smaller cone was only weakly active. The southernmost lava flow had reached 1,800 m elevation in an area 1.5 km NW of Nez coupé du Tremblet. During 4-5 October tremor levels fluctuated. Lava effusion increased, averaging 10 meters per second with peaks at 25 meters per second. Lava was ejected above the main vent, which was 23 m wide; the smaller vent was not active. The eruption stopped or paused at 0748 on 5 October based on visual observations and a sudden halt in tremor signals.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Trident (United States) | 28 September-4 October 2022 | New Activity / Unrest Cite this Report

Trident
Alaska Peninsula Volcanic Arc

AVO raised the Aviation Color Code for Trident to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) on 29 September due to an ongoing seismic swarm. The swarm began on 24 August and within about four days the seismic network began detecting episodes of weak seismic tremor and low frequency earthquakes. The events were initially located at depths around 25 km, but then they progressively shallowed to around 5 km by 28 August. Earthquakes were located 3-6 km deep since then, though some deeper events were recorded. AVO attributed the swarm to moving magma or magmatic fluids and noted that seismic swarms had previously been recorded with no subsequent eruptions.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Aira (Japan) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Aira
Ryukyu Volcanic Arc

JMA reported that 11 eruptive events and five explosions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 26 September-3 October. Volcanic plumes rose as high as 2.8 km above the crater rim and large blocks were ejected as far as 1.7 km from the vent. Incandescence at the crater was visible nightly. 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)

Ebeko (Russia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Ebeko
Kuril Volcanic Arc

KVERT reported that moderate activity at Ebeko was ongoing. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose to 3.5 km (11,500 ft) a.s.l. and drifted E during 22-24 and 27-28 September. On 22 and 28 September the ash plumes that drifted E and N produced ashfall in Severo-Kurilsk. A thermal anomaly over the volcano was identified in satellite images on 23 and 28 September. 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)

Great Sitkin (United States) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Great Sitkin
Aleutian Ridge Volcanic Arc

AVO reported that continuing slow lava effusion at Great Sitkin was confirmed by a 27 September satellite image and likely continued during 28 September-4 October. Elevated surface temperatures were identified during 28-29 September; weather clouds often prevented webcam and satellite views during the rest of the week. Seismicity remained at low levels. 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 level on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Karthala (Comoros) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Karthala
Comoros Hotspot Volcano Group

According to the Direction Générale de la Sécurité Civile (DGSC) – Comores on 4 October, the Observatoire Volcanologique du Karthala (OVK) reported that activity at Karthala had significantly declined during the previous few days. OVK recommended that the Alert Level remain at Yellow (the second lowest level on a four-level scale).

Source: Direction Générale de la Sécurité Civile – Comores

Kilauea (United States) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Kilauea
Hawaiian-Emperor Hotspot Volcano Group

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 27 September-4 October, entering the lava lake. The active part of the lake stayed at a relatively steady level through the week, varying only slightly. Sulfur dioxide emissions were approximately 970 and 1,800 tonnes per day on 28 and 30 September, respectively. 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 level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Lewotolok (Indonesia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Lewotolok
Sunda Volcanic Arc

PVMBG reported that the eruption at Lewotolok continued during 27 September-4 October. White emissions rose as high as 350 m above the summit and drifted E, SE, W, and NW on most days. White-and-gray plumes rose as high 500 m and drifted NW, W, and E during 29-30 September and 1-2 October. 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)

Marapi (Indonesia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Marapi
Sunda Volcanic Arc

PVMBG reported that seismicity at Marapi increased on 29 September, with 146 deep volcanic earthquakes recorded by the seismic network. Surficial activity showed no changes. The Alert Level remained at 1 (on a scale of 1-4).

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

Merapi (Indonesia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Merapi
Sunda Volcanic Arc

BPPTKG reported that the eruption at Merapi continued during 23-29 September and seismicity remained at high levels. As many as seven lava avalanches from the SW lava dome traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. No morphological changes to the central lava domes were evident in photographs, while the SW dome grew about 1 m taller. 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)

Nevados de Chillan (Chile) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Nevados de Chillan
Andean Southern Volcanic Arc

SERNAGEOMIN reported that two long-period earthquake signals were recorded at Nevados de Chillán at 0813 on 3 October and 1630 on 4 October, and both were followed by a dense ash emission. The ash plume from the first event rose 760 m above the summit and drifted SSW, while the ash plume from the second event rose as high as 1.9 km and also drifted SSW. The Alert Level remained at Yellow, the second lowest level on a four-color scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the communities of Pinto and Coihueco, and reminded residents not to approach the crater within 2 km.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Pavlof (United States) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Pavlof
Aleutian Ridge Volcanic Arc

AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 27 September-4 October. Seismic tremor continued, and a few small earthquakes were recorded during 28-29 September. Weather clouds often prevented views of the volcano, though elevated surface temperatures were identified in satellite images on a few of the days. Diffuse steam plumes were visible in webcam views during 30 September-2 October. 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 level on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sabancaya (Peru) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Sabancaya
Andean Central Volcanic Arc

Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 September with a daily average of 46 explosions. Gas-and-ash plumes rose as high as 3 km above the summit and drifted NE, E, and SE. As many as nine thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.

Source: Instituto Geofísico del Perú (IGP)

Semeru (Indonesia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Semeru
Sunda Volcanic Arc

PVMBG reported that the eruption at Semeru continued during 27 September-4 October. Eruptive events at 0459 and 0726 on 2 October produced ash plumes that rose 500-700 m above the summit and drifted S and SW. 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, and 500 m 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 (United States) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Semisopochnoi
Aleutian Ridge Volcanic Arc

On 29 September AVO lowered the Aviation Color Code for Semisopochnoi to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) noting that no ash emissions or explosive activity had been detected since 14 September. Seismicity had decreased, though remained at elevated levels. Steam emissions from the active vent in the N crater of Mount Cerberus persisted. Seismic tremor and a small explosion were detected in seismic and infrasound data during 3-4 October.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sheveluch (Russia) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Sheveluch
Eastern Kamchatka Volcanic Arc

KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 15-22 September. A daily thermal anomaly was identified in satellite images. Plumes of re-suspended ash drifted 113 km E on 23 September. 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)

Stromboli (Italy) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Stromboli
Aeolian Volcanic Arc

INGV reported that during 26 September-2 October activity at Stromboli was characterized by ongoing explosions from three vents in Area N (North Crater area) and at least two vents in Area C-S (South-Central Crater area). Low-intensity explosions from the N1 vent (Area N) ejected course material (bombs and lapilli) 80-150 m high at a rate of 3-5 explosions per hour. Spattering was visible at the N2 vent (Area N). Explosions from at least two vents in Area C-S, which were not visible due to the camera views, ejected ash and course material less than 150 m above the vent at a rate of 1-5 events per hour.

At 1524 on 29 September an explosion at N2 generated an ash plume that rose 300 m above the summit and ejected abundant amounts of lava fragments, lapilli, and bombs along the Sciara del Fuoco. Four subsequent, low-intensity explosions ejected tephra 100 m high. Spattering activity at the vent intensified afterwards and through the next day. Beginning at 1115 on 3 October a lava flow emerged from Area N and traveled down the Sciara del Fuoco, reaching the ocean.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Suwanosejima (Japan) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Volcanic Arc

JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 30 September-3 October. A total of 38 explosions produced eruption plumes that rose as high as 1.6 km above the crater rim and occasionally ejected large bombs from the vent. Crater incandescence was visible nightly and ash sometimes fell in Toshima village (3.5 km SSW). The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater. [Correction: JMA noted that the number of explosions had been increasing since 26 September; they raised the Alert Level to 3 on 28 September.]

Source: Japan Meteorological Agency (JMA)

Taal (Philippines) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Taal
Taiwan-Luzon Volcanic Arc

In a special advisory, PHIVOLCS reported that sulfur dioxide emissions at Taal were as high as 10,718 tonnes per day on 29 September, creating a significant amount of vog over the caldera. Voggy conditions were reported by residents of Laurel, Agoncillo, and Santa Teresita, Batangas. The report noted that sulfur dioxide emissions had been increasing since 15 July and averaged 6,612 tonnes per day in September. In early August degassing at the volcano increased characterized by the upwelling of hot fluids in the lake and steam-rich plumes rising as high as 2.5 km above the lake’s surface. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS warned the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Ta'u (United States) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Ta'u
Samoan Hotspot Volcano Group

HVO lowered the Volcano Alert Level for Ta’u to Normal (the lowest level on a four-level scale) and the Aviation Color Code to Green (the lowest level on a four-color scale) on 3 October, noting that seismic activity had dramatically decreased and maintained low levels over the past few weeks. Analysis of data from one seismometer that had recorded earthquakes during 2005-2009 suggested that a rate of five detected earthquakes per day was characteristic of long-term background seismicity; the current earthquakes rates were at background levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Villarrica (Chile) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Villarrica
Andean Southern Volcanic Arc

On 3 October SERNAGEOMIN reported that recent passive emissions from Villarrica contained tephra that was deposited on the upper SW flank. Evidence suggested that there were recent fluctuations in the intensity of activity at the lava lake in the main crater. The Alert Level remained at Green, the lowest level on a four-color scale.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Whakaari/White Island (New Zealand) | 28 September-4 October 2022 | Continuing ActivityCite this Report

Whakaari/White Island
Taupo Volcanic Zone

GeoNet reported that the minor ash and sulfur dioxide emissions from the active vent area in Whakaari/White Island’s crater only occurred on 18 September based on subsequent webcam and satellite images. The most likely cause for the emission was a gas release from small amount of magma moving into the shallow part of the volcano, though there was no evidence of increasing activity at the volcano. On 30 September the Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) and the Volcanic Alert Level remained at 2 (on a scale of 0-5).

Source: GeoNet

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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.

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