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 6 September-12 September 2023
Name	Location	Eruption Start Date	Report Status
Kilauea	Hawaiian Islands (USA)	—	New
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Ebeko	Paramushir Island (Russia)	2022 Jun 11	Continuing
Great Sitkin	Andreanof Islands (USA)	2021 May 25	Continuing
Kanlaon	Philippines	—	Continuing
Klyuchevskoy	Central Kamchatka (Russia)	—	Continuing
Krakatau	Sunda Strait	—	Continuing
Lewotolok	Lembata Island	2020 Nov 27	Continuing
Lokon-Empung	Sulawesi	—	Continuing
Mayon	Luzon (Philippines)	2023 Apr 27 ± 2 days	Continuing
Merapi	Central Java	2020 Dec 31	Continuing
Rincon de la Vieja	Costa Rica	2021 Jun 28	Continuing
Sabancaya	Peru	2016 Nov 6	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Shishaldin	Fox Islands (USA)	—	Continuing
Soufriere Hills	Montserrat	—	Continuing
Stromboli	Aeolian Islands (Italy)	1934 Feb 2	Continuing
Suwanosejima	Ryukyu Islands (Japan)	2004 Oct 23	Continuing
Tungurahua	Ecuador	—	Continuing
Ubinas	Peru	—	Continuing

All times are local unless otherwise stated.

Kilauea | 6 September-12 September 2023 | New Activity / Unrest Cite this Report

Kilauea
Hawaiian Islands (USA)

HVO reported that a new eruption began in Kilauea’s Halema`uma`u Crater on 10 September following a period of increased seismicity. Seismicity increased on 22 August; most of the earthquakes were located at depths of 2-3 km and were all smaller than M2. About 150 occurred during 9-10 September. Tiltmeter and Global Positioning System (GPS) data showed inflation in the S portion of the crater.

At 0252 on 10 September HVO raised the Volcano Alert Level to Watch (the third level on a four-level scale) and the Aviation Color Code to Orange (the third level on a four-color scale) due to increased earthquake activity and changes in ground deformation that indicated magma moving towards the surface. An eruption commenced at about 1515 in the E part of the caldera based on field reports and webcam images. Fissures opened on the crater floor and produced lava fountains and flows. The Volcano Alert Level and Aviation Color Code were raised to Warning and Red, respectively. Gas-and-steam plumes rose from the fissures and drifted downwind. By 1900 the line of fissures was about 1.4 km long and extended into the E wall of the down-dropped block. Multiple active fountains were about 20-25 m high; fountains at the initial eruption onset were an estimated 50 m.

At 0810 on 11 September the Volcano Alert Level was lowered back to Watch and the Aviation Color Code was lowered back to Orange because the style of eruption and fissure location had stabilized, the initial extremely high effusion rates had declined (but remained at high levels), and no infrastructure was threatened. The eruption plume, mainly comprised of sulfur dioxide and particulates, rose as high as 3 km (10,000 ft) a.s.l. and had become less dense. Lava erupted from fissures on the down-dropped block flowed W towards Halema`uma`u, covering much of the surface with active lava as deep as about 2.5 m. During 11-12 September easternmost vents on the down-dropped block and the westernmost vents in Halema`uma`u became inactive; the active vents were E-W-trending and spanned a distance of about 750 m. Channelized lava flows traveled N and W onto the Halema`uma`u Crater floor, burying the E rim of the crater and most of the crater floor; higher older lava flows prevented movement onto the SW part of the floor. Lava fountaining continued, rising as high as 15 m by the morning of 12 September. A laser rangefinder pointed at the W portion of the crater recorded almost 5 m of uplift from the magmatic intrusion beneath the caldera since the onset of the eruption.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Aira | 6 September-12 September 2023 | Continuing ActivityCite this Report

Aira
Kyushu (Japan)

JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 4-11 September. Incandescence at Minamidake was observed nightly. Very small eruptive events occurred at both craters on 4 September. Sulfur dioxide emissions were slightly high at 1,600 tons per day on that same day. An explosion on 1512 on 9 September produced an ash plume that rose 800 m above the crater rim and ejected large blocks 500-700 m from the crater. Another explosion at 0018 on 11 September generated an ash plume that rose 1.1 km and ejected large blocks 300-500 m; an ash plume rose 1.3 km from an explosion at 1642 on that same day. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.

Source: Japan Meteorological Agency (JMA)

Ebeko | 6 September-12 September 2023 | Continuing ActivityCite this Report

Ebeko
Paramushir Island (Russia)

KVERT reported that moderate explosive activity at Ebeko was ongoing during 31 August-7 September. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 31 August and 2-5 September generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l and drifted to the E. A thermal anomaly was identified in satellite images during 4-5 September; weather clouds obscured views on other days. The Aviation Color Code remained at Orange (the third 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 | 6 September-12 September 2023 | Continuing ActivityCite this Report

Great Sitkin
Andreanof Islands (USA)

AVO reported that slow lava effusion likely continued at Great Sitkin during 6-12 September, producing a thick flow in the summit crater that mainly expanded E. Seismicity was low; earthquakes were detected daily and were numerous during 6-7 September. Web camera images showed diffuse gas emissions rising from the summit during 6-7 September and weakly elevated surface temperatures were identified in satellite data during 6-7 and 10-11 September. Weather clouds often prevented satellite and webcam observations. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Kanlaon | 6 September-12 September 2023 | Continuing ActivityCite this Report

Kanlaon
Philippines

PHIVOLCS issued a special notice for Kanlaon at 0900 on 6 September, noting increased seismicity. The seismic network detected 36 volcanic earthquakes including 34 volcano-tectonic earthquakes between 0500 on 4 September and 0750 on 6 September at depths of 0-9 km beneath the NE flank. The earthquakes had local magnitudes of 0.8-3.4. Ground deformation data from continuous GPS and electronic tilt data had been recording inflation at the mid-flanks of the volcano since March. Sulfur dioxide emissions at the summit crater averaged 788 and 301 tonnes per day (t/d) on 7 and 11 September, respectively. The number of volcano-tectonic earthquakes decreased during the rest of the week; there were 23 recorded during 6-7 September and 2-9 daily earthquakes during 8-12 September. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Klyuchevskoy | 6 September-12 September 2023 | Continuing ActivityCite this Report

Klyuchevskoy
Central Kamchatka (Russia)

KVERT reported that the explosive Strombolian eruption at Klyuchevskoy continued 31 August-7 September. A bright thermal anomaly was identified in satellite images every day, except on 7 September due to weather clouds. Lava fountaining fed flows that advanced down the Apakhonchichsky and Kozyrevsky drainages. Plumes of resuspended ash drifted 120 km E during 3-5 September. The Aviation Color Code remained at Yellow (the second 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 | 6 September-12 September 2023 | Continuing ActivityCite this Report

Krakatau
Sunda Strait

PVMBG reported that white gas-and-steam plumes rose as high as 300 m above Krakatau’s summit on most days during 6-12 September and drifted NW and NE. White, gray, and black ash plumes of variable densities rose as high as 1 km and drifted N, NE, and E during 10-11 September. White-and-black ash plumes rose as high as 100 m and drifted N on 12 September. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay at least 5 km away from the crater.

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

Lewotolok | 6 September-12 September 2023 | Continuing ActivityCite this Report

Lewotolok
Lembata Island

PVMBG reported that the eruption at Lewotolok continued during 6-12 September. White-and-gray plumes rose 100-500 m above the summit and drifted W and NW during 4-6 September. White steam-and-gas plumes rose as high as 400 m and drifted W and NW each day during the rest of the week. 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 summit crater.

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

Lokon-Empung | 6 September-12 September 2023 | Continuing ActivityCite this Report

Lokon-Empung
Sulawesi

PVMBG reported that activity at Lokon Empung had decreased during the previous few weeks. Seismicity notably decreased during 21-22 July; volcanic earthquakes started to become less frequent and tremor amplitude significantly decreased. Gas-and-steam emissions had variable densities but decreased from a maximum height of 400 m above the crater during 18-31 July to a maximum height of 200 m above the crater during 1-20 August. At 1200 on 21 August the Alert Level was lowered to 2 (on a sale of 1-4) and the public was reminded not to approach Tompaluan Crater within a radius of 1.5 km.

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

Mayon | 6 September-12 September 2023 | Continuing ActivityCite this Report

Mayon
Luzon (Philippines)

PHIVOLCS reported that the eruption at Mayon continued during 6-12 September. The lengths of the lava flow in the Mi-Isi (S), Bonga (SE), and Basud (E) drainages remained at 2.8 km, 3.4 km, and 1.1 km, respectively. Collapses at the lava dome and from the lava flows produced incandescent rockfalls and pyroclastic density currents (PDCs, or pyroclastic flows) that descended the flanks as far as 4 km. Each day seismic stations recorded 118-239 rockfall events, 0-3 PDC events, and 3-35 daily volcanic earthquakes. Daily sulfur dioxide emissions averaged between 609 and 2,252 tonnes per day, with the highest value recorded on 8 September. One ash emission was recorded during 11-12 September. The Alert Level remained at 3 (on a 0-5 scale) and residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ). PHIVOLCS recommended that civil aviation authorities advise pilots to avoid flying close to the summit.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Merapi | 6 September-12 September 2023 | Continuing ActivityCite this Report

Merapi
Central Java

BPPTKG reported that the eruption at Merapi (on Java) continued during 1-7 September and seismicity remained at elevated levels. The SW lava dome produced a total of 154 lava avalanches that descended the S and SW flanks; five traveled as far as 1.5 km down the upper part of the Boyong drainage, 146 traveled as far as 2 km down the upper Bebeng drainage, and three traveled 1.5 km down the Senowo drainage. Morphological changes to the SW lava dome were due to continuing collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location.

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

Rincon de la Vieja | 6 September-12 September 2023 | Continuing ActivityCite this Report

Rincon de la Vieja
Costa Rica

OVSICORI-UNA reported that daily gas-and-steam emissions continued at Rincón de la Vieja during 6-12 September rising as high as 1 km above the crater rim. Some of the emissions were produced by small phreatic events. The Alert Level remained at Level 3, Orange, the third level on a four-level scale.

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

Sabancaya | 6 September-12 September 2023 | Continuing ActivityCite this Report

Sabancaya
Peru

Instituto Geofísico del Perú (IGP) reported that the eruption at Sabancaya continued during 4-10 September with a daily average of 13 explosions. Gas-and-ash plumes rose as high as 2.3 km above the summit and drifted SE, E, NE, and NW. A total of 10 thermal anomalies from the lava dome in the summit crater were detected using satellite data. Minor inflation was detected near the Hualca Hualca sector (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)

Sheveluch | 6 September-12 September 2023 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that the eruption at Sheveluch continued during 31 August-7 September. Intense fumarolic activity was visible at the active dome, and thermal anomalies were identified in satellite images on all days except 7 September (due to weather clouds). Plumes of resuspended ash drifted 650 km SE and E during 31 August and 3-4 September. The Aviation Color Code remained at Orange (the third 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)

Shishaldin | 6 September-12 September 2023 | Continuing ActivityCite this Report

Shishaldin
Fox Islands (USA)

AVO reported that the eruption at Shishaldin continued during 6-12 September. Seismicity remains elevated and characterized by weak but steady tremor, small low-frequency earthquakes, and small explosions; explosions were not reported on 12 September. Elevated surface temperatures were identified daily in satellite images and were sometimes intense. A Significant Meteorological Information (SIGMET) notice issued on 6 September advised aircraft of a low-level ash plume drifting SSE at 1.5-1.8 km (5,000-6,000 ft) a.s.l. Small plumes visible in webcam images drifted ESE and SSE during 6-7 September. Additional small diffuse steam-and-gas plumes from the summit were observed in web camera images during 9-11 September. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Soufriere Hills | 6 September-12 September 2023 | Continuing ActivityCite this Report

Soufriere Hills
Montserrat

MVO reported that a very small increase in activity at Soufrière Hills during 1-8 September was characterized by small rockfalls coincident with volcano-tectonic earthquake activity and occasional small, low-frequency, volcanic earthquakes. The seismic network recorded 27 volcano-tectonic earthquakes spilt between two swarms recorded on 6 and 8 September. Minor rockfall activity and volcano-tectonic seismicity began at about 2100 on 7 September and was ongoing. Rockfalls took place on the lava dome based on seismic data, though their locations could not be visually confirmed. The swarm on 8 September was followed by a long-period earthquake at 0742, and a few additional smaller events. Access to the Upper Belham valley and Plymouth were suspended for the day out of an abundance of caution. Sulfur dioxide emissions averaged 436 tonnes per day on 1 September (measured from a boat) and 367 tonnes per day on 6 September (measured by helicopter). The Hazard Level remained at 1 (on a scale of 1-5).

Source: Montserrat Volcano Observatory (MVO)

Stromboli | 6 September-12 September 2023 | Continuing ActivityCite this Report

Stromboli
Aeolian Islands (Italy)

INGV reported that eruptive activity continued at Stromboli during 4-10 September. Webcam images showed Strombolian activity at three vents in Area N (one at N1 and two at N2), within the upper part of the Sciara del Fuoco, and from two vents in Area C-S (South-Central Crater) in the crater terrace. Low- and medium-intensity explosions at a rate of 6-9 per hour from Area N2 ejected mainly coarse material (bombs and lapilli), sometimes mixed with ash, up to 200 m above the vents. Intense spattering occurred at N1 on 4 September. Low- to medium-intensity explosions averaged 5-14 per hour from the two vents in sector S2 (Area C-S), ejecting a mix of coarse material and ash as high as 200 m. The Dipartimento della Protezione Civile maintained the Alert Level at Yellow (the second highest level on a four-level scale).

Sources: Sezione di Catania - Osservatorio Etneo (INGV), Dipartimento della Protezione Civile

Suwanosejima | 6 September-12 September 2023 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Islands (Japan)

JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 4-11 September. Eruptive events at 0221, 0301, and 0333 on 9 September produced ash plumes that rose 1.1-1.4 km above the crater rim and drifted W. Ash emissions were continuous during 0404-0740 and rose as high as 2 km above the crater rim. More eruptive events at 1437 on 10 September and at 0319 on 11 September produced ash plumes that rose 1.7-1.8 km. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Tungurahua | 6 September-12 September 2023 | Continuing ActivityCite this Report

Tungurahua
Ecuador

The Washington VAAC reported that at 0820 on 7 September a plume of resuspended ash at Tungurahua drifted W at an altitude of 4.9 km (16,000 ft) a.s.l., based on weather models and satellite images. The plume had dissipated by 1440.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Ubinas | 6 September-12 September 2023 | Continuing ActivityCite this Report

Ubinas
Peru

Instituto Geofísico del Perú (IGP) reported that the eruption at Ubinas continued at low-to-moderate levels during 4-10 September. There were daily averages of 183 volcano-tectonic earthquakes indicating rock fracturing and 27 long-period earthquakes signifying the movement of gas and magma. Gas-and-steam emissions rose as high as 1 km above the crater rim and drifted as far as 5 km NE, E, and SE; no explosions or ash plumes were recorded during the week. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay 4 km away from the crater.

Source: Instituto Geofísico del Perú (IGP)

Weekly Reports Archive

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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 Kilauea
HVO reported that a new eruption began in Kilauea’s Halema`uma`u Crater on 10 September following a period of increased seismicity. Seismicity increased on 22 August; most of the earthquakes were located at depths of 2-3 km and were all smaller than M2. About 150 occurred during 9-10 September. Tiltmeter and Global Positioning System (GPS) data showed inflation in the S portion of the crater.

At 0252 on 10 September HVO raised the Volcano Alert Level to Watch (the third level on a four-level scale) and the Aviation Color Code to Orange (the third level on a four-color scale) due to increased earthquake activity and changes in ground deformation that indicated magma moving towards the surface. An eruption commenced at about 1515 in the E part of the caldera based on field reports and webcam images. Fissures opened on the crater floor and produced lava fountains and flows. The Volcano Alert Level and Aviation Color Code were raised to Warning and Red, respectively. Gas-and-steam plumes rose from the fissures and drifted downwind. By 1900 the line of fissures was about 1.4 km long and extended into the E wall of the down-dropped block. Multiple active fountains were about 20-25 m high; fountains at the initial eruption onset were an estimated 50 m.

At 0810 on 11 September the Volcano Alert Level was lowered back to Watch and the Aviation Color Code was lowered back to Orange because the style of eruption and fissure location had stabilized, the initial extremely high effusion rates had declined (but remained at high levels), and no infrastructure was threatened. The eruption plume, mainly comprised of sulfur dioxide and particulates, rose as high as 3 km (10,000 ft) a.s.l. and had become less dense. Lava erupted from fissures on the down-dropped block flowed W towards Halema`uma`u, covering much of the surface with active lava as deep as about 2.5 m. During 11-12 September easternmost vents on the down-dropped block and the westernmost vents in Halema`uma`u became inactive; the active vents were E-W-trending and spanned a distance of about 750 m. Channelized lava flows traveled N and W onto the Halema`uma`u Crater floor, burying the E rim of the crater and most of the crater floor; higher older lava flows prevented movement onto the SW part of the floor. Lava fountaining continued, rising as high as 15 m by the morning of 12 September. A laser rangefinder pointed at the W portion of the crater recorded almost 5 m of uplift from the magmatic intrusion beneath the caldera since the onset of the eruption.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Aira
JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 4-11 September. Incandescence at Minamidake was observed nightly. Very small eruptive events occurred at both craters on 4 September. Sulfur dioxide emissions were slightly high at 1,600 tons per day on that same day. An explosion on 1512 on 9 September produced an ash plume that rose 800 m above the crater rim and ejected large blocks 500-700 m from the crater. Another explosion at 0018 on 11 September generated an ash plume that rose 1.1 km and ejected large blocks 300-500 m; an ash plume rose 1.3 km from an explosion at 1642 on that same day. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.
Source: Japan Meteorological Agency (JMA)

Report for Ebeko
KVERT reported that moderate explosive activity at Ebeko was ongoing during 31 August-7 September. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 31 August and 2-5 September generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l and drifted to the E. A thermal anomaly was identified in satellite images during 4-5 September; weather clouds obscured views on other days. The Aviation Color Code remained at Orange (the third 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 Great Sitkin
AVO reported that slow lava effusion likely continued at Great Sitkin during 6-12 September, producing a thick flow in the summit crater that mainly expanded E. Seismicity was low; earthquakes were detected daily and were numerous during 6-7 September. Web camera images showed diffuse gas emissions rising from the summit during 6-7 September and weakly elevated surface temperatures were identified in satellite data during 6-7 and 10-11 September. Weather clouds often prevented satellite and webcam observations. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Kanlaon
PHIVOLCS issued a special notice for Kanlaon at 0900 on 6 September, noting increased seismicity. The seismic network detected 36 volcanic earthquakes including 34 volcano-tectonic earthquakes between 0500 on 4 September and 0750 on 6 September at depths of 0-9 km beneath the NE flank. The earthquakes had local magnitudes of 0.8-3.4. Ground deformation data from continuous GPS and electronic tilt data had been recording inflation at the mid-flanks of the volcano since March. Sulfur dioxide emissions at the summit crater averaged 788 and 301 tonnes per day (t/d) on 7 and 11 September, respectively. The number of volcano-tectonic earthquakes decreased during the rest of the week; there were 23 recorded during 6-7 September and 2-9 daily earthquakes during 8-12 September. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Report for Klyuchevskoy
KVERT reported that the explosive Strombolian eruption at Klyuchevskoy continued 31 August-7 September. A bright thermal anomaly was identified in satellite images every day, except on 7 September due to weather clouds. Lava fountaining fed flows that advanced down the Apakhonchichsky and Kozyrevsky drainages. Plumes of resuspended ash drifted 120 km E during 3-5 September. The Aviation Color Code remained at Yellow (the second 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 white gas-and-steam plumes rose as high as 300 m above Krakatau’s summit on most days during 6-12 September and drifted NW and NE. White, gray, and black ash plumes of variable densities rose as high as 1 km and drifted N, NE, and E during 10-11 September. White-and-black ash plumes rose as high as 100 m and drifted N on 12 September. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay at least 5 km away from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Lewotolok
PVMBG reported that the eruption at Lewotolok continued during 6-12 September. White-and-gray plumes rose 100-500 m above the summit and drifted W and NW during 4-6 September. White steam-and-gas plumes rose as high as 400 m and drifted W and NW each day during the rest of the week. 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 summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Lokon-Empung
PVMBG reported that activity at Lokon Empung had decreased during the previous few weeks. Seismicity notably decreased during 21-22 July; volcanic earthquakes started to become less frequent and tremor amplitude significantly decreased. Gas-and-steam emissions had variable densities but decreased from a maximum height of 400 m above the crater during 18-31 July to a maximum height of 200 m above the crater during 1-20 August. At 1200 on 21 August the Alert Level was lowered to 2 (on a sale of 1-4) and the public was reminded not to approach Tompaluan Crater within a radius of 1.5 km.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Mayon
PHIVOLCS reported that the eruption at Mayon continued during 6-12 September. The lengths of the lava flow in the Mi-Isi (S), Bonga (SE), and Basud (E) drainages remained at 2.8 km, 3.4 km, and 1.1 km, respectively. Collapses at the lava dome and from the lava flows produced incandescent rockfalls and pyroclastic density currents (PDCs, or pyroclastic flows) that descended the flanks as far as 4 km. Each day seismic stations recorded 118-239 rockfall events, 0-3 PDC events, and 3-35 daily volcanic earthquakes. Daily sulfur dioxide emissions averaged between 609 and 2,252 tonnes per day, with the highest value recorded on 8 September. One ash emission was recorded during 11-12 September. The Alert Level remained at 3 (on a 0-5 scale) and residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ). PHIVOLCS recommended that civil aviation authorities advise pilots to avoid flying close to the summit.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Report for Merapi
BPPTKG reported that the eruption at Merapi (on Java) continued during 1-7 September and seismicity remained at elevated levels. The SW lava dome produced a total of 154 lava avalanches that descended the S and SW flanks; five traveled as far as 1.5 km down the upper part of the Boyong drainage, 146 traveled as far as 2 km down the upper Bebeng drainage, and three traveled 1.5 km down the Senowo drainage. Morphological changes to the SW lava dome were due to continuing collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location.
Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)

Report for Rincon de la Vieja
OVSICORI-UNA reported that daily gas-and-steam emissions continued at Rincón de la Vieja during 6-12 September rising as high as 1 km above the crater rim. Some of the emissions were produced by small phreatic events. The Alert Level remained at Level 3, Orange, the third level on a four-level scale.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Report for Sabancaya
Instituto Geofísico del Perú (IGP) reported that the eruption at Sabancaya continued during 4-10 September with a daily average of 13 explosions. Gas-and-ash plumes rose as high as 2.3 km above the summit and drifted SE, E, NE, and NW. A total of 10 thermal anomalies from the lava dome in the summit crater were detected using satellite data. Minor inflation was detected near the Hualca Hualca sector (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)

Report for Sheveluch
KVERT reported that the eruption at Sheveluch continued during 31 August-7 September. Intense fumarolic activity was visible at the active dome, and thermal anomalies were identified in satellite images on all days except 7 September (due to weather clouds). Plumes of resuspended ash drifted 650 km SE and E during 31 August and 3-4 September. The Aviation Color Code remained at Orange (the third 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 Shishaldin
AVO reported that the eruption at Shishaldin continued during 6-12 September. Seismicity remains elevated and characterized by weak but steady tremor, small low-frequency earthquakes, and small explosions; explosions were not reported on 12 September. Elevated surface temperatures were identified daily in satellite images and were sometimes intense. A Significant Meteorological Information (SIGMET) notice issued on 6 September advised aircraft of a low-level ash plume drifting SSE at 1.5-1.8 km (5,000-6,000 ft) a.s.l. Small plumes visible in webcam images drifted ESE and SSE during 6-7 September. Additional small diffuse steam-and-gas plumes from the summit were observed in web camera images during 9-11 September. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Soufriere Hills
MVO reported that a very small increase in activity at Soufrière Hills during 1-8 September was characterized by small rockfalls coincident with volcano-tectonic earthquake activity and occasional small, low-frequency, volcanic earthquakes. The seismic network recorded 27 volcano-tectonic earthquakes spilt between two swarms recorded on 6 and 8 September. Minor rockfall activity and volcano-tectonic seismicity began at about 2100 on 7 September and was ongoing. Rockfalls took place on the lava dome based on seismic data, though their locations could not be visually confirmed. The swarm on 8 September was followed by a long-period earthquake at 0742, and a few additional smaller events. Access to the Upper Belham valley and Plymouth were suspended for the day out of an abundance of caution. Sulfur dioxide emissions averaged 436 tonnes per day on 1 September (measured from a boat) and 367 tonnes per day on 6 September (measured by helicopter). The Hazard Level remained at 1 (on a scale of 1-5).
Source: Montserrat Volcano Observatory (MVO)

Report for Stromboli
INGV reported that eruptive activity continued at Stromboli during 4-10 September. Webcam images showed Strombolian activity at three vents in Area N (one at N1 and two at N2), within the upper part of the Sciara del Fuoco, and from two vents in Area C-S (South-Central Crater) in the crater terrace. Low- and medium-intensity explosions at a rate of 6-9 per hour from Area N2 ejected mainly coarse material (bombs and lapilli), sometimes mixed with ash, up to 200 m above the vents. Intense spattering occurred at N1 on 4 September. Low- to medium-intensity explosions averaged 5-14 per hour from the two vents in sector S2 (Area C-S), ejecting a mix of coarse material and ash as high as 200 m. The Dipartimento della Protezione Civile maintained the Alert Level at Yellow (the second highest level on a four-level scale).
Sources: Sezione di Catania - Osservatorio Etneo (INGV), Dipartimento della Protezione Civile

Report for Suwanosejima
JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 4-11 September. Eruptive events at 0221, 0301, and 0333 on 9 September produced ash plumes that rose 1.1-1.4 km above the crater rim and drifted W. Ash emissions were continuous during 0404-0740 and rose as high as 2 km above the crater rim. More eruptive events at 1437 on 10 September and at 0319 on 11 September produced ash plumes that rose 1.7-1.8 km. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1 km away from the crater.
Source: Japan Meteorological Agency (JMA)

Report for Tungurahua
The Washington VAAC reported that at 0820 on 7 September a plume of resuspended ash at Tungurahua drifted W at an altitude of 4.9 km (16,000 ft) a.s.l., based on weather models and satellite images. The plume had dissipated by 1440.
Source: Washington Volcanic Ash Advisory Center (VAAC)

Report for Ubinas
Instituto Geofísico del Perú (IGP) reported that the eruption at Ubinas continued at low-to-moderate levels during 4-10 September. There were daily averages of 183 volcano-tectonic earthquakes indicating rock fracturing and 27 long-period earthquakes signifying the movement of gas and magma. Gas-and-steam emissions rose as high as 1 km above the crater rim and drifted as far as 5 km NE, E, and SE; no explosions or ash plumes were recorded during the week. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay 4 km away from the crater.
Source: Instituto Geofísico del Perú (IGP)