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 31 May-6 June 2023
Name	Location	Eruption Start Date	Report Status
Ahyi	Mariana Islands (USA)	—	New
Karangetang	Sangihe Islands	2018 Nov 25	New
Kilauea	Hawaiian Islands (USA)	—	New
Mayon	Luzon (Philippines)	2023 Apr 27 ± 2 days	New
Nyamulagira	DR Congo	2018 Apr 18	New
Popocatepetl	Mexico	2005 Jan 9	New
Rincon de la Vieja	Costa Rica	2021 Jun 28	New
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Bezymianny	Central Kamchatka (Russia)	2016 Dec 5	Continuing
Bulusan	Luzon (Philippines)	—	Continuing
Cotopaxi	Ecuador	—	Continuing
Ebeko	Paramushir Island (Russia)	2022 Jun 11	Continuing
Fuego	South-Central Guatemala	2002 Jan 4	Continuing
Great Sitkin	Andreanof Islands (USA)	2021 May 25	Continuing
Ibu	Halmahera	2008 Apr 5	Continuing
Iliamna	Alaska Peninsula	—	Continuing
Krakatau	Sunda Strait	—	Continuing
Lewotolok	Lembata Island	2020 Nov 27	Continuing
Merapi	Central Java	2020 Dec 31	Continuing
Nevado del Ruiz	Colombia	2014 Nov 18	Continuing
Nyiragongo	DR Congo	—	Continuing
Sabancaya	Peru	2016 Nov 6	Continuing
Sangay	Ecuador	2019 Mar 26	Continuing
Santa Maria	Southwestern Guatemala	1922 Jun 22	Continuing
Semeru	Eastern Java	2017 Jun 6	Continuing
Semisopochnoi	Aleutian Islands (USA)	—	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Suwanosejima	Ryukyu Islands (Japan)	2004 Oct 23	Continuing
Taal	Luzon (Philippines)	2024 Apr 12	Continuing

All times are local unless otherwise stated.

Ahyi | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Ahyi
Mariana Islands (USA)

Unrest at Ahyi Seamount continued during 30 May-7 June. A possible hydroacoustic signal was detected by pressure sensors on Wake Island (2,270 km E) during 2-3 June. No activity was visible in cloudy satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).

Source: US Geological Survey

Karangetang | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Karangetang
Sangihe Islands

Webcam images of Karangetang published in PVMBG daily reports periodically showed incandescence at Main Crater (S crater) and from material on the flanks of Main Crater during 31 May-6 June. Daily white gas-and-steam plumes were visible rising as high as 150 m above the summit and drifting in various directions. According to the Darwin VAAC ash plumes rose as high as 2.1 km (7,000 ft) a.s.l. and drifted SE and E during 2-4 June. The Alert Level remained at 3 (on a scale of 1-4) and the public were advised to stay 2.5 km away from Main Crater with an extension to 3.5 km on the S and SE flanks.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Kilauea | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Kilauea
Hawaiian Islands (USA)

HVO reported that earthquake activity and changes in the patterns of ground deformation beneath Kilauea’s summit began to be detected during the evening of 6 June. The data indicated magma movement towards the surface, prompting HVO to raise the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest level on a four-color scale).

At about 0444 on 7 June incandescence in Halema’uma’u Crater was visible in webcam images indicting that a new eruption had begun. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. Lava flowed from fissures that had opened on the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Mayon | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Mayon
Luzon (Philippines)

Daily visual and webcam observations of Mayon’s summit crater revealed more frequent rockfalls at the summit lava dome starting in the last week of April, indicating aseismic dome growth. The lava dome increased in volume by about 83,000 cubic meters during 3 February-9 May, with a total addition of nearly 164,000 cubic meters since 20 August 2022. Sulfur dioxide emission averages were as high as 576 tons per day on 29 April and 162 tons per day on 23 May. A total of 26 volcanic earthquakes had been recorded since 1 April. Electronic Distance Measuring (EDM), precise leveling, continuous GPS, and electronic tilt monitoring data showed that the volcano had been slightly inflated, especially on the NW and SE flanks, since 2020. Short-term inflation on the upper flanks had been detected since February.

From 0500 on 4 June to 0500 on 5 June the number of rockfalls increased from an average of 5 events per day to 49 events per day. At 1000 on 5 June the Alert Level was raised to 2 (on a 0-5 scale). PHIVOLCS noted that although low-level volcanic earthquakes, ground deformation, and volcanic gas emissions indicated unrest, the steep increase in rockfall frequency may indicate increased dome activity. Residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Nyamulagira | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Nyamulagira
DR Congo

On 1 June the Observatoire Volcanologique de Goma (OVG) reported that seismicity at Nyamulagira remained at lower levels, similar to those recorded before the 17 May increase in activity. Incandescence above the crater had been absent for the past three days, but satellite imagery showed continuing lava effusion within the summit crater. The recent flows on the flanks covered an estimated 0.6 square kilometers.

Source: Observatoire Volcanologique de Goma (OVG)

Popocatepetl | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Popocatepetl
Mexico

CENAPRED reported that during 30 May-6 June activity at Popocatépetl consisted of seismic tremor, a few explosions, emissions of steam and gas, with occasional ash, and ejections of incandescent material. There were 67-315 daily steam-and-gas emissions, sometimes containing minor amounts of ash, with the highest number recorded during 30-31 May. Overall activity decreased during the week. Explosions at 1423 and 1708 on 30 May produced gray ash plumes. During 30-31 May incandescent material was ejected from the vent short distances onto the flank. High-frequency tremor was recorded by the seismic network for around eight and a half hours, and was associated with nearly continuous emissions of steam, gas, and ash. Ashfall was reported in Ayapeango (22 km NW) and Acatzingo (100 km W), in the State of Mexico. A M1.6 volcano tectonic (VT) earthquake was recorded at 0952 on 31 May. The Washington VAAC stated that although ash emissions continued to be visible in satellite and webcam images drifting SSE, the intensity of the emissions had decreased.

CENAPRED stated on 1 June that tremor signals had significantly decreased during the previous few days, and on 2 June that overall activity had also decreased. Periods of high-frequency, low-amplitude tremor continued to be detected during the rest of the week. A period of tremor recorded during 1635-1850 on 3 June was associated with diffuse ash emissions that drifted SE. According to the Washington VAAC ash plumes during 1-3 June rose 5.5-6.7 km (18,000-22,000 ft) a.s.l., or as high as 1.3 km above the summit, and drifted SW, SSW, and SE. A minor explosion occurred at 0739 on 4 June. A minor explosion occurred at 1211 on 5 June and a M1.2 VT earthquake was recorded at 1818. On 6 June the Alert Level was lowered to Yellow, Phase Two (the middle level on a three-color scale).

Sources: Washington Volcanic Ash Advisory Center (VAAC), Centro Nacional de Prevencion de Desastres (CENAPRED)

Rincon de la Vieja | 31 May-6 June 2023 | New Activity / Unrest Cite this Report

Rincon de la Vieja
Costa Rica

OVSICORI-UNA reported that increased eruptive activity continued at Rincón de la Vieja during 30 May-6 June. Seismic instruments continued to record low-magnitude volcano-tectonic earthquakes located S of the Pailas sector of Parque Nacional Rincón de la Vieja. Reports describing phreatic eruption events were issued almost daily. A phreatic event at 2215 on 30 May ejected incandescent material within the vicinity of the crater. A small phreatic eruption at 1753 on 31 May generated a small pyroclastic flow that traveled a short distance from the crater. Moderate phreatic eruptions were recorded during 1-2 June; the most energetic event occurred at 0902 and generated a plume of steam, gas, and ash that rose to 1.5 km above the crater and drifted N. OVSICORI-UNA raised the Alert Level from 2 to 3 (the third highest on a four-level scale) at 1650 on 2 June due to significant seismicity and significant emissions recorded during May.

Eruptive events were recorded during 3-4 June. The most energetic event occurred at 0624 on 3 June and generated a steam-and-gas plume that rose 1.5 km and drifted W. An eruptive event at 0526 on 4 June first generated emissions that rose to 500 m, followed at 0529 by a second plume of steam-and-gas rose to 3.5 km above the crater and drifted N. Steam-and-gas plumes with low ash content were generated from eruptive events during the nights of 4-5 June; the plumes rose 1-1.5 km above the crater and drifted W. At 0259 on 6 June a small phreatic eruption generated a plume that rose to 3 km and drifted NW.

During a press conference held by OVISOCORI-UNA, RSN, and CNE on 5 June, the public was reminded that although the recent volcanic activity is normal for Rincon de la Vieja, it is still necessary to remain cautious and that community emergency committees will remain activated. CNE maintained a Green Alert (first alert level on a four-color scale) for the districts of Dos Ríos (13 km N) and Aguas Claras (3 km NW) in the canton of Upala (22 km ENE), as well as the districts of Cañas Dulces (24 km ESE), Curubandé (18 km SW), and Mayorga (15 km W) in the canton of Liberia (21 km SW). The CNE reminded the public to stay away from the Azul, Pénjamo, and Azufrada rivers.

Sources: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA), Comisión Nacional de Prevención de Riesgos y Atención de Emergencias (CNE), Red Sismologica Nacional (RSN: UCR-ICE), Universidad de Costa Rica and Instituto Costarricense de Electricidad

Aira | 31 May-6 June 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 29 May-5 June. On 29 May sulfur dioxide emissions were high at 2,900 tons per day. Crater incandescence was observed nightly at both craters during 29 May-2 June, and very small eruptive events periodically occurred. Eruptive events at Minamidake at 0237 and 0454 on 4 June produced ash plumes that rose about 1.1 km above the crater rim. An explosion at 0012 on 5 June generated an ash plume that rose 1 km and drifted SE, and ejected blocks 500-700 m from the crater. At Showa, eruptive events at 0211, 0352, 0440, and 1436 on 5 June generated ash plumes that rose 1.3-1.5 km above the crater rim and drifted SE and E, or rose straight up; blocks were ejected as far as 300 m from the crater. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from both craters.

Source: Japan Meteorological Agency (JMA)

Bezymianny | 31 May-6 June 2023 | Continuing ActivityCite this Report

Bezymianny
Central Kamchatka (Russia)

KVERT reported that eruptive activity at Bezymianny was generally characterized by lava effusion, gas-and-steam emissions, and lava dome incandescence during 25 May-1 June. A daily thermal anomaly was identified in satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Bulusan | 31 May-6 June 2023 | Continuing ActivityCite this Report

Bulusan
Luzon (Philippines)

In a special advisory, PHIVOLCS reported that from 0500 on 31 May to 1500 on 1 June the seismic network at Bulusan recorded a total of 19 volcanic earthquakes. Out of those, five were located at depths of 2.7-6.6 km beneath the E part of the volcano and had local magnitudes of 1.8-2.7. Minor white steam emissions from the summit crater and active vents on the SE flank were occasionally visible. Ground deformation data from electronic tiltmeter stations continued to record short-term inflation of the SE flanks, first detected in December 2022. The Alert Level remained at 0 (the lowest level on a scale of 0-5) and PHIVOLCS reminded the public not to enter the 4-km-radius Permanent Danger Zone (PDZ).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Cotopaxi | 31 May-6 June 2023 | Continuing ActivityCite this Report

Cotopaxi
Ecuador

IG reported that moderate eruptive activity continued at Cotopaxi during 30 May-6 June. Seismic activity was mainly characterized by long-period earthquakes and tremors associated with daily emissions. Although weather clouds often obscured views, emissions were visible almost daily. During 30-31 May ash-and-gas emissions rose as high as 500 m above the summit and drifted W and NW. A tremor signal associated with an ash emission was detected on 1 June, though weather clouds prevented visual confirmation; ashfall was reported in San Ramón (108 km N) and San Agustín de Callo (16 km WSW). Multiple ash emissions were reported on 3 June; ash plumes rose as high as around 1 km above the summit and drifted SW, W, and NW. During 4-5 June several gas-and-ash emissions rose 400-800 m and drifted W and SW. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)

Ebeko | 31 May-6 June 2023 | Continuing ActivityCite this Report

Ebeko
Paramushir Island (Russia)

KVERT reported that moderate activity at Ebeko was ongoing during 25 May-1 June. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 25 and 27-28 May generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l. and drifted NE. A thermal anomaly was identified in satellite images on 26 May and 1 June. 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)

Fuego | 31 May-6 June 2023 | Continuing ActivityCite this Report

Fuego
South-Central Guatemala

INSIVUMEH reported that daily gas emissions rose from Fuego during 31 May-4 June. During 2-3 June minor explosions occurring at a rate of two per hour produced diffuse ash plumes that rose 450 m above the summit and drifted 10 km W and SE. Minor ashfall was reported in El Zapote (10 km SSE), La Rochela (8 km SSW), and San Andrés Osuna (12 km SSW).

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Great Sitkin | 31 May-6 June 2023 | Continuing ActivityCite this Report

Great Sitkin
Andreanof Islands (USA)

AVO reported that slow lava effusion continued at Great Sitkin during 30 May-6 June producing a thick lava flow confined to the summit crater. Seismicity remained low; a few local earthquakes were recorded daily. Slightly elevated surface temperatures were identified in satellite images during 30-31 May and 3-4 June. Satellite data during 5-6 June confirmed that the flow was expanding E. 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)

Ibu | 31 May-6 June 2023 | Continuing ActivityCite this Report

Ibu
Halmahera

PVMBG reported that Ibu continued to erupt during 31 May-6 June. White-and-gray ash plumes of variable densities rose as high as 1 km above the summit and drifted in multiple directions during 31 May-1 June [correction: 31 May-6 June]. According to the Darwin VAAC ash plume rose 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted SE, E, and NE on 2 and 5 June. The Alert Level remained at a 2 (the second highest level on a four-level scale), and the public was advised to stay outside of the 2 km hazard radius, and to stay 3.5 km away from the N area of the active crater.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Iliamna | 31 May-6 June 2023 | Continuing ActivityCite this Report

Iliamna
Alaska Peninsula

AVO reported that seismic activity at Iliamna began to increase at around 1200 on 5 June. Initially earthquakes occurred about every one minute, then became more closely spaced. The source of the activity was possibly from movement of magma or hydrothermal fluids beneath the volcano, though similar activity had been observed before large mass movements or avalanches; AVO could not rule out either. The Aviation Color Code was raised to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level was raised to Advisory (the second lowest level on a four-level scale).

The earthquake activity culminated in an ice-rock avalanche just before 1714. There was no visual confirmation, but the signals matched historical observations associated with avalanches at Red Glacier on the E flank. Seismicity declined to background levels. The Aviation Color Code was lowered to Green (the lowest level on a four-color scale) and the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Krakatau | 31 May-6 June 2023 | Continuing ActivityCite this Report

Krakatau
Sunda Strait

PVMBG reported that at 1434 on 6 June a dense gray ash plume from Anak Krakatau rose around 500 m above the summit and drifted NW. 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 | 31 May-6 June 2023 | Continuing ActivityCite this Report

Lewotolok
Lembata Island

PVMBG reported that the eruption at Lewotolok continued during 31 May-6 June. Ash plumes were periodically visible through the week. Dense white-and-gray ash plumes rose as high as 600 m above the summit and drifted W and NW on 1 June. Ash plumes on 2 June rose as high as 1 km and drifted W and SW. A dense ash plume rose 550 m and drifted SW on 5 June. 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 in all directions.

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

Merapi | 31 May-6 June 2023 | Continuing ActivityCite this Report

Merapi
Central Java

BPPTKG reported that the eruption at Merapi (on Java) continued during 26 May-1 June and seismicity remained at elevated levels. The SW lava dome produced 155 lava avalanches that traveled as far as 2 km down the SW flank (upstream in the Bebeng and Boyong drainages) and one that traveled 500 m NW (upstream of the Senowo River). Morphological changes to the SW lava dome due to continuing collapses of material were evident in webcam images. 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)

Nevado del Ruiz | 31 May-6 June 2023 | Continuing ActivityCite this Report

Nevado del Ruiz
Colombia

Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that the eruption at Nevado del Ruiz continued during 31 May-6 June and was characterized by periodic gas, steam, and ash emissions, and thermal anomalies at the lava dome in Arenas Crater. Seismicity fluctuated at low levels; on 31 May SGC stated that during the past several days seismicity had decreased compared to the previous weeks. Daily gas-and-steam emissions were visible in webcam images and contained ash on most days; emissions rose as high as 2 km above the crater and mainly drifted NW. Ash emissions were confirmed in satellite images on the other days according to the Washington VAAC. A significant thermal anomaly was observed within the crater on 31 May. That same day a sulfur odor was reported in Cerro Gualí. Minor ashfall was reported in the municipalities of Villamaría (28 km NW) and Manizales (28 km NW) on 4 June. The Alert Level was remained at Orange, Level II (the second highest level on a four-level scale).

Source: Servicio Geológico Colombiano (SGC)

Nyiragongo | 31 May-6 June 2023 | Continuing ActivityCite this Report

Nyiragongo
DR Congo

The Observatoire Volcanologique de Goma (OVG) characterized activity at Nyiragongo during 27 May-4 June as normal. Sulfur dioxide emissions were low. Faint incandescence at the crater was observed at 1900 on 4 June. The Alert Level remained at Yellow.

Source: Observatoire Volcanologique de Goma (OVG)

Sabancaya | 31 May-6 June 2023 | Continuing ActivityCite this Report

Sabancaya
Peru

Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 29 May-4 June with a daily average of 24 explosions. Gas-and-ash plumes rose as high as 2.1 km above the summit and drifted NW and W. Six 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)

Sangay | 31 May-6 June 2023 | Continuing ActivityCite this Report

Sangay
Ecuador

IG reported that the eruption at Sangay continued at a high level during 30 May-6 June, though weather clouds often prevented visual observations. The seismic network recorded 504-528 explosions per day during 30 May-2 June and 158-384 per day during the rest of the week. Periods of occasional-to-frequent ash plumes were reported almost daily. Incandescence at the crater was visible during 31 May and 3-4 June; incandescent material traveled 1 km down the SE flank. Ashfall was reported on 1 June in Cebadas Parish, Chimborazo Province (33 km WNW). On 4 June an ash plume rose to 1.1 km above the crater and drifted W and SW. During 4-5 June incandescent material traveled 1 km down the SE flank. Several steam-and-ash plumes rose as high as 1.1 km above the summit and drifted W. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE), Washington Volcanic Ash Advisory Center (VAAC)

Santa Maria | 31 May-6 June 2023 | Continuing ActivityCite this Report

Santa Maria
Southwestern Guatemala

INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 31 May-6 June. Effusion from the Caliente dome complex fed lava flows that descended the San Isidro and Zanjón Seco drainages on the W and SW flanks; the main lava flow was 4.3 km long and remained active. Avalanches of material from the growing dome and occasional explosions descended all flanks of the dome, and avalanches from the margins of lava flows descended the S and SW flanks. Incandescence from the dome and lava flows was visible during the nights and early mornings. An average of 1-2 explosions per hour were recorded on most days, generating ash-and-steam plumes that rose up to 1 km above the dome and on some days drifted S and SE.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Semeru | 31 May-6 June 2023 | Continuing ActivityCite this Report

Semeru
Eastern Java

PVMBG reported that the eruption at Semeru continued during 31 May-6 June. Steam-and-gas plumes were occasionally visible, though weather clouds often obscured visual observations. White-and-gray ash plumes rose 300-500 m above the summit and drifted W and NW on 3 June. The Alert Level remained at 3 (third highest on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages 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 | 31 May-6 June 2023 | Continuing ActivityCite this Report

Semisopochnoi
Aleutian Islands (USA)

AVO reported that low-level unrest continued at Semisopochnoi during 30 May-6 June. Seismicity remained low and few earthquakes were detected. Minor steam emissions were occasionally visible in webcam images on 31 May and 2 and 4 June. The Volcano Alert Level remained at Advisory (the second highest on a four-level scale) and the Aviation Color Code remained at Yellow (the second highest color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Sheveluch | 31 May-6 June 2023 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that the eruption at Sheveluch was ongoing during 25 May-1 June. Intense fumarolic activity at the active crater was likely associated with growth of Karan lava dome. A thermal anomaly over the active crater and Karan dome area was identified in satellite images during 25-30 May; weather clouds obscured the volcano on the other days. Plumes of ash, originally deposited during the 10-13 April eruption and resuspended by strong winds, were visible in satellite images drifting 120 km ESE during 27-28 May. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Suwanosejima | 31 May-6 June 2023 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Islands (Japan)

JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 29 May-5 June. At 1407 on 30 May an explosion generated an ash plume that rose 800 m. Incandescence at the crater was visible at night during 2-5 June. Four eruptive events occurred during 4-5 June. Ash plumes rose to 1.1 km and drifted E and S at 1455 and 2327 on 4 June, respectively. At 1037 and 2349 on 5 June ash plumes rose 1-1.1 km and drifted E. 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)

Taal | 31 May-6 June 2023 | Continuing ActivityCite this Report

Taal
Luzon (Philippines)

In a 2 June advisory PHIVOLCS reported continuing low-level unrest at Taal. Starting at 0635 on 2 June relatively weak but continuous volcanic tremor located at shallow depths along the Daang Kastila fissure was recorded by all 15 seismic stations of the Taal Volcano Network. At the same time webcams recorded upwelling in Main Crater Lake on Taal Volcano Island (TVI) and more intense thermal anomalies in the N portion of the lake. Pronounced inflation in the SW part of Taal Volcano Island was detected towards the end of May, following a longer phase of deflation in that same sector. Sulfur dioxide gas emissions had slightly increased during the previous two weeks, averaging 5,360 tonnes per day during 22 May-1 June, higher than the 3,000 tonnes per day average recorded during 1 April-21 May. Emissions averaged 5,831 tonnes per day on 1 June. PHIVOLCS stated that a new phase of magma degassing at depth was likely driving the increased shallow hydrothermal activity.

At 2230 on 3 June visible upwelling of volcanic fluids in the lake produced voluminous steam-rich plumes that rose 3 km above TVI. Significant vog was detected in the caldera and reported by residents in the municipalities of Balete (E of Taal Lake), and Laurel and Agoncillo (both W of Taal Lake), Batangas. Upwelling of how fluids in the lake continued during 4-7 June and steam-rich plumes rose as high as 3 km above the lake and drifted NE and NNE. Sulfur dioxide gas emissions averaged 9,391 tonnes per day on 5 June and 7,680 tonnes per day on 6 June; significant vog persisted over the Taal region. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

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The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. At the end of each report is a list of the sources used. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. This feature was first made available on 5 March 2008.

Download Smithsonian / USGS Weekly Volcanic Activity Report Network CAP Feed

The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.

Download Smithsonian / USGS Weekly Volcanic Activity Report Network Link

A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

Criteria & Disclaimers

Criteria

The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:

- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.

Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.

It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.

Disclaimers

1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are cover longer time periods and are more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.

3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

5. USGS Disclaimer Statement for this Website:

Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL: https://volcano.si.edu/reports_weekly.cfm

Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

CVGHM (formerly VSI) - Center of Volcanology and Geological Hazard Mitigation

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

IGNS - Institute of Geological and Nuclear Sciences (New Zealand) - now GNS Science

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

INGV-CT - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (Italy)

INSIVUMEH - Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (Guatemala)

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

NIED - National Research Institute for Earth Science and Disaster Prevention (Japan)

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

OVDAS - Observatorio Volcanologico de los Andes del Sur (Chile)

OFDA - Office of US Foreign Disaster Assistance

ONEMI - Oficina Nacional de Emergencia - Ministerio del Interior (Chile)

OVPDLF - Observatoire Volcanologique du Piton de la Fournaise (France)

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

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)

Report for Ahyi
Unrest at Ahyi Seamount continued during 30 May-7 June. A possible hydroacoustic signal was detected by pressure sensors on Wake Island (2,270 km E) during 2-3 June. No activity was visible in cloudy satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).
Source: US Geological Survey

Report for Karangetang
Webcam images of Karangetang published in PVMBG daily reports periodically showed incandescence at Main Crater (S crater) and from material on the flanks of Main Crater during 31 May-6 June. Daily white gas-and-steam plumes were visible rising as high as 150 m above the summit and drifting in various directions. According to the Darwin VAAC ash plumes rose as high as 2.1 km (7,000 ft) a.s.l. and drifted SE and E during 2-4 June. The Alert Level remained at 3 (on a scale of 1-4) and the public were advised to stay 2.5 km away from Main Crater with an extension to 3.5 km on the S and SE flanks.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Kilauea
HVO reported that earthquake activity and changes in the patterns of ground deformation beneath Kilauea’s summit began to be detected during the evening of 6 June. The data indicated magma movement towards the surface, prompting HVO to raise the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest level on a four-color scale).

At about 0444 on 7 June incandescence in Halema’uma’u Crater was visible in webcam images indicting that a new eruption had begun. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. Lava flowed from fissures that had opened on the crater floor.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Mayon
Daily visual and webcam observations of Mayon’s summit crater revealed more frequent rockfalls at the summit lava dome starting in the last week of April, indicating aseismic dome growth. The lava dome increased in volume by about 83,000 cubic meters during 3 February-9 May, with a total addition of nearly 164,000 cubic meters since 20 August 2022. Sulfur dioxide emission averages were as high as 576 tons per day on 29 April and 162 tons per day on 23 May. A total of 26 volcanic earthquakes had been recorded since 1 April. Electronic Distance Measuring (EDM), precise leveling, continuous GPS, and electronic tilt monitoring data showed that the volcano had been slightly inflated, especially on the NW and SE flanks, since 2020. Short-term inflation on the upper flanks had been detected since February.

From 0500 on 4 June to 0500 on 5 June the number of rockfalls increased from an average of 5 events per day to 49 events per day. At 1000 on 5 June the Alert Level was raised to 2 (on a 0-5 scale). PHIVOLCS noted that although low-level volcanic earthquakes, ground deformation, and volcanic gas emissions indicated unrest, the steep increase in rockfall frequency may indicate increased dome activity. Residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ).
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Report for Nyamulagira
On 1 June the Observatoire Volcanologique de Goma (OVG) reported that seismicity at Nyamulagira remained at lower levels, similar to those recorded before the 17 May increase in activity. Incandescence above the crater had been absent for the past three days, but satellite imagery showed continuing lava effusion within the summit crater. The recent flows on the flanks covered an estimated 0.6 square kilometers.
Source: Observatoire Volcanologique de Goma (OVG)

Report for Popocatepetl
CENAPRED reported that during 30 May-6 June activity at Popocatépetl consisted of seismic tremor, a few explosions, emissions of steam and gas, with occasional ash, and ejections of incandescent material. There were 67-315 daily steam-and-gas emissions, sometimes containing minor amounts of ash, with the highest number recorded during 30-31 May. Overall activity decreased during the week. Explosions at 1423 and 1708 on 30 May produced gray ash plumes. During 30-31 May incandescent material was ejected from the vent short distances onto the flank. High-frequency tremor was recorded by the seismic network for around eight and a half hours, and was associated with nearly continuous emissions of steam, gas, and ash. Ashfall was reported in Ayapeango (22 km NW) and Acatzingo (100 km W), in the State of Mexico. A M1.6 volcano tectonic (VT) earthquake was recorded at 0952 on 31 May. The Washington VAAC stated that although ash emissions continued to be visible in satellite and webcam images drifting SSE, the intensity of the emissions had decreased.

CENAPRED stated on 1 June that tremor signals had significantly decreased during the previous few days, and on 2 June that overall activity had also decreased. Periods of high-frequency, low-amplitude tremor continued to be detected during the rest of the week. A period of tremor recorded during 1635-1850 on 3 June was associated with diffuse ash emissions that drifted SE. According to the Washington VAAC ash plumes during 1-3 June rose 5.5-6.7 km (18,000-22,000 ft) a.s.l., or as high as 1.3 km above the summit, and drifted SW, SSW, and SE. A minor explosion occurred at 0739 on 4 June. A minor explosion occurred at 1211 on 5 June and a M1.2 VT earthquake was recorded at 1818. On 6 June the Alert Level was lowered to Yellow, Phase Two (the middle level on a three-color scale).
Sources: Washington Volcanic Ash Advisory Center (VAAC), Centro Nacional de Prevencion de Desastres (CENAPRED)

Report for Rincon de la Vieja
OVSICORI-UNA reported that increased eruptive activity continued at Rincón de la Vieja during 30 May-6 June. Seismic instruments continued to record low-magnitude volcano-tectonic earthquakes located S of the Pailas sector of Parque Nacional Rincón de la Vieja. Reports describing phreatic eruption events were issued almost daily. A phreatic event at 2215 on 30 May ejected incandescent material within the vicinity of the crater. A small phreatic eruption at 1753 on 31 May generated a small pyroclastic flow that traveled a short distance from the crater. Moderate phreatic eruptions were recorded during 1-2 June; the most energetic event occurred at 0902 and generated a plume of steam, gas, and ash that rose to 1.5 km above the crater and drifted N. OVSICORI-UNA raised the Alert Level from 2 to 3 (the third highest on a four-level scale) at 1650 on 2 June due to significant seismicity and significant emissions recorded during May.

Eruptive events were recorded during 3-4 June. The most energetic event occurred at 0624 on 3 June and generated a steam-and-gas plume that rose 1.5 km and drifted W. An eruptive event at 0526 on 4 June first generated emissions that rose to 500 m, followed at 0529 by a second plume of steam-and-gas rose to 3.5 km above the crater and drifted N. Steam-and-gas plumes with low ash content were generated from eruptive events during the nights of 4-5 June; the plumes rose 1-1.5 km above the crater and drifted W. At 0259 on 6 June a small phreatic eruption generated a plume that rose to 3 km and drifted NW.

During a press conference held by OVISOCORI-UNA, RSN, and CNE on 5 June, the public was reminded that although the recent volcanic activity is normal for Rincon de la Vieja, it is still necessary to remain cautious and that community emergency committees will remain activated. CNE maintained a Green Alert (first alert level on a four-color scale) for the districts of Dos Ríos (13 km N) and Aguas Claras (3 km NW) in the canton of Upala (22 km ENE), as well as the districts of Cañas Dulces (24 km ESE), Curubandé (18 km SW), and Mayorga (15 km W) in the canton of Liberia (21 km SW). The CNE reminded the public to stay away from the Azul, Pénjamo, and Azufrada rivers.
Sources: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA), Comisión Nacional de Prevención de Riesgos y Atención de Emergencias (CNE), Red Sismologica Nacional (RSN: UCR-ICE), Universidad de Costa Rica and Instituto Costarricense de Electricidad

Report for Aira
JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 29 May-5 June. On 29 May sulfur dioxide emissions were high at 2,900 tons per day. Crater incandescence was observed nightly at both craters during 29 May-2 June, and very small eruptive events periodically occurred. Eruptive events at Minamidake at 0237 and 0454 on 4 June produced ash plumes that rose about 1.1 km above the crater rim. An explosion at 0012 on 5 June generated an ash plume that rose 1 km and drifted SE, and ejected blocks 500-700 m from the crater. At Showa, eruptive events at 0211, 0352, 0440, and 1436 on 5 June generated ash plumes that rose 1.3-1.5 km above the crater rim and drifted SE and E, or rose straight up; blocks were ejected as far as 300 m from the crater. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from both craters.
Source: Japan Meteorological Agency (JMA)

Report for Bezymianny
KVERT reported that eruptive activity at Bezymianny was generally characterized by lava effusion, gas-and-steam emissions, and lava dome incandescence during 25 May-1 June. A daily thermal anomaly was identified in satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Bulusan
In a special advisory, PHIVOLCS reported that from 0500 on 31 May to 1500 on 1 June the seismic network at Bulusan recorded a total of 19 volcanic earthquakes. Out of those, five were located at depths of 2.7-6.6 km beneath the E part of the volcano and had local magnitudes of 1.8-2.7. Minor white steam emissions from the summit crater and active vents on the SE flank were occasionally visible. Ground deformation data from electronic tiltmeter stations continued to record short-term inflation of the SE flanks, first detected in December 2022. The Alert Level remained at 0 (the lowest level on a scale of 0-5) and PHIVOLCS reminded the public not to enter the 4-km-radius Permanent Danger Zone (PDZ).
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Report for Cotopaxi
IG reported that moderate eruptive activity continued at Cotopaxi during 30 May-6 June. Seismic activity was mainly characterized by long-period earthquakes and tremors associated with daily emissions. Although weather clouds often obscured views, emissions were visible almost daily. During 30-31 May ash-and-gas emissions rose as high as 500 m above the summit and drifted W and NW. A tremor signal associated with an ash emission was detected on 1 June, though weather clouds prevented visual confirmation; ashfall was reported in San Ramón (108 km N) and San Agustín de Callo (16 km WSW). Multiple ash emissions were reported on 3 June; ash plumes rose as high as around 1 km above the summit and drifted SW, W, and NW. During 4-5 June several gas-and-ash emissions rose 400-800 m and drifted W and SW. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)

Report for Ebeko
KVERT reported that moderate activity at Ebeko was ongoing during 25 May-1 June. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 25 and 27-28 May generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l. and drifted NE. A thermal anomaly was identified in satellite images on 26 May and 1 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Fuego
INSIVUMEH reported that daily gas emissions rose from Fuego during 31 May-4 June. During 2-3 June minor explosions occurring at a rate of two per hour produced diffuse ash plumes that rose 450 m above the summit and drifted 10 km W and SE. Minor ashfall was reported in El Zapote (10 km SSE), La Rochela (8 km SSW), and San Andrés Osuna (12 km SSW).
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Report for Great Sitkin
AVO reported that slow lava effusion continued at Great Sitkin during 30 May-6 June producing a thick lava flow confined to the summit crater. Seismicity remained low; a few local earthquakes were recorded daily. Slightly elevated surface temperatures were identified in satellite images during 30-31 May and 3-4 June. Satellite data during 5-6 June confirmed that the flow was expanding E. 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)

Report for Ibu
PVMBG reported that Ibu continued to erupt during 31 May-6 June. White-and-gray ash plumes of variable densities rose as high as 1 km above the summit and drifted in multiple directions during 31 May-1 June [correction: 31 May-6 June]. According to the Darwin VAAC ash plume rose 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted SE, E, and NE on 2 and 5 June. The Alert Level remained at a 2 (the second highest level on a four-level scale), and the public was advised to stay outside of the 2 km hazard radius, and to stay 3.5 km away from the N area of the active crater.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Iliamna
AVO reported that seismic activity at Iliamna began to increase at around 1200 on 5 June. Initially earthquakes occurred about every one minute, then became more closely spaced. The source of the activity was possibly from movement of magma or hydrothermal fluids beneath the volcano, though similar activity had been observed before large mass movements or avalanches; AVO could not rule out either. The Aviation Color Code was raised to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level was raised to Advisory (the second lowest level on a four-level scale).

The earthquake activity culminated in an ice-rock avalanche just before 1714. There was no visual confirmation, but the signals matched historical observations associated with avalanches at Red Glacier on the E flank. Seismicity declined to background levels. The Aviation Color Code was lowered to Green (the lowest level on a four-color scale) and the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Krakatau
PVMBG reported that at 1434 on 6 June a dense gray ash plume from Anak Krakatau rose around 500 m above the summit and drifted NW. 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 31 May-6 June. Ash plumes were periodically visible through the week. Dense white-and-gray ash plumes rose as high as 600 m above the summit and drifted W and NW on 1 June. Ash plumes on 2 June rose as high as 1 km and drifted W and SW. A dense ash plume rose 550 m and drifted SW on 5 June. 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 in all directions.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Merapi
BPPTKG reported that the eruption at Merapi (on Java) continued during 26 May-1 June and seismicity remained at elevated levels. The SW lava dome produced 155 lava avalanches that traveled as far as 2 km down the SW flank (upstream in the Bebeng and Boyong drainages) and one that traveled 500 m NW (upstream of the Senowo River). Morphological changes to the SW lava dome due to continuing collapses of material were evident in webcam images. 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 Nevado del Ruiz
Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that the eruption at Nevado del Ruiz continued during 31 May-6 June and was characterized by periodic gas, steam, and ash emissions, and thermal anomalies at the lava dome in Arenas Crater. Seismicity fluctuated at low levels; on 31 May SGC stated that during the past several days seismicity had decreased compared to the previous weeks. Daily gas-and-steam emissions were visible in webcam images and contained ash on most days; emissions rose as high as 2 km above the crater and mainly drifted NW. Ash emissions were confirmed in satellite images on the other days according to the Washington VAAC. A significant thermal anomaly was observed within the crater on 31 May. That same day a sulfur odor was reported in Cerro Gualí. Minor ashfall was reported in the municipalities of Villamaría (28 km NW) and Manizales (28 km NW) on 4 June. The Alert Level was remained at Orange, Level II (the second highest level on a four-level scale).
Source: Servicio Geológico Colombiano (SGC)

Report for Nyiragongo
The Observatoire Volcanologique de Goma (OVG) characterized activity at Nyiragongo during 27 May-4 June as normal. Sulfur dioxide emissions were low. Faint incandescence at the crater was observed at 1900 on 4 June. The Alert Level remained at Yellow.
Source: Observatoire Volcanologique de Goma (OVG)

Report for Sabancaya
Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 29 May-4 June with a daily average of 24 explosions. Gas-and-ash plumes rose as high as 2.1 km above the summit and drifted NW and W. Six 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)

Report for Sangay
IG reported that the eruption at Sangay continued at a high level during 30 May-6 June, though weather clouds often prevented visual observations. The seismic network recorded 504-528 explosions per day during 30 May-2 June and 158-384 per day during the rest of the week. Periods of occasional-to-frequent ash plumes were reported almost daily. Incandescence at the crater was visible during 31 May and 3-4 June; incandescent material traveled 1 km down the SE flank. Ashfall was reported on 1 June in Cebadas Parish, Chimborazo Province (33 km WNW). On 4 June an ash plume rose to 1.1 km above the crater and drifted W and SW. During 4-5 June incandescent material traveled 1 km down the SE flank. Several steam-and-ash plumes rose as high as 1.1 km above the summit and drifted W. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE), Washington Volcanic Ash Advisory Center (VAAC)

Report for Santa Maria
INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 31 May-6 June. Effusion from the Caliente dome complex fed lava flows that descended the San Isidro and Zanjón Seco drainages on the W and SW flanks; the main lava flow was 4.3 km long and remained active. Avalanches of material from the growing dome and occasional explosions descended all flanks of the dome, and avalanches from the margins of lava flows descended the S and SW flanks. Incandescence from the dome and lava flows was visible during the nights and early mornings. An average of 1-2 explosions per hour were recorded on most days, generating ash-and-steam plumes that rose up to 1 km above the dome and on some days drifted S and SE.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Report for Semeru
PVMBG reported that the eruption at Semeru continued during 31 May-6 June. Steam-and-gas plumes were occasionally visible, though weather clouds often obscured visual observations. White-and-gray ash plumes rose 300-500 m above the summit and drifted W and NW on 3 June. The Alert Level remained at 3 (third highest on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Semisopochnoi
AVO reported that low-level unrest continued at Semisopochnoi during 30 May-6 June. Seismicity remained low and few earthquakes were detected. Minor steam emissions were occasionally visible in webcam images on 31 May and 2 and 4 June. The Volcano Alert Level remained at Advisory (the second highest on a four-level scale) and the Aviation Color Code remained at Yellow (the second highest color on a four-color scale).
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Sheveluch
KVERT reported that the eruption at Sheveluch was ongoing during 25 May-1 June. Intense fumarolic activity at the active crater was likely associated with growth of Karan lava dome. A thermal anomaly over the active crater and Karan dome area was identified in satellite images during 25-30 May; weather clouds obscured the volcano on the other days. Plumes of ash, originally deposited during the 10-13 April eruption and resuspended by strong winds, were visible in satellite images drifting 120 km ESE during 27-28 May. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Report for Suwanosejima
JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 29 May-5 June. At 1407 on 30 May an explosion generated an ash plume that rose 800 m. Incandescence at the crater was visible at night during 2-5 June. Four eruptive events occurred during 4-5 June. Ash plumes rose to 1.1 km and drifted E and S at 1455 and 2327 on 4 June, respectively. At 1037 and 2349 on 5 June ash plumes rose 1-1.1 km and drifted E. 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 Taal
In a 2 June advisory PHIVOLCS reported continuing low-level unrest at Taal. Starting at 0635 on 2 June relatively weak but continuous volcanic tremor located at shallow depths along the Daang Kastila fissure was recorded by all 15 seismic stations of the Taal Volcano Network. At the same time webcams recorded upwelling in Main Crater Lake on Taal Volcano Island (TVI) and more intense thermal anomalies in the N portion of the lake. Pronounced inflation in the SW part of Taal Volcano Island was detected towards the end of May, following a longer phase of deflation in that same sector. Sulfur dioxide gas emissions had slightly increased during the previous two weeks, averaging 5,360 tonnes per day during 22 May-1 June, higher than the 3,000 tonnes per day average recorded during 1 April-21 May. Emissions averaged 5,831 tonnes per day on 1 June. PHIVOLCS stated that a new phase of magma degassing at depth was likely driving the increased shallow hydrothermal activity.

At 2230 on 3 June visible upwelling of volcanic fluids in the lake produced voluminous steam-rich plumes that rose 3 km above TVI. Significant vog was detected in the caldera and reported by residents in the municipalities of Balete (E of Taal Lake), and Laurel and Agoncillo (both W of Taal Lake), Batangas. Upwelling of how fluids in the lake continued during 4-7 June and steam-rich plumes rose as high as 3 km above the lake and drifted NE and NNE. Sulfur dioxide gas emissions averaged 9,391 tonnes per day on 5 June and 7,680 tonnes per day on 6 June; significant vog persisted over the Taal region. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ).
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)