Aira (Japan) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano). No eruptive events were recorded during 5-15 May, though inflation continued to be detected in deformation data, notably starting at 2000 on 12 May. Sulfur dioxide emissions were slightly low, averaging 300 tons per day (t/d); the last measurement was 900 t/d on 2 May. Continuous eruptive activity, including seven explosions, began at around 1045 on 15 May and ended at around 0400 on 16 May, producing ash plumes that rose as high has 3 km above the summit and drifted in multiple directions. Large blocks were ejected as far as 1.2 km from the vent. Field observations confirmed notable ashfall on the E part of the island on 15 May and the N side of the island on 16 May. Deformation data showed a period of deflation after explosions on 15 May, then inflation resumed. Eruptive activity occurred intermittently during 16 May through at least 1500 on 19 May; 86 eruptive events and 44 explosions were detected, generating ash plumes that generally rose as high as 2.9 km above the crater and ejecting blocks as far as 900 m from the crater rim. An ash plume from an explosion at 1854 on 18 May rose 3.2 km above the crater rim and rifted SE, and large blocks were ejected as far as 1.2 km from the crater rim. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to be cautious within 2 km of both the Minimadake and Showa craters.

Source: Japan Meteorological Agency (JMA)

Dukono (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 14-20 May. Daily white-and-gray or white, gray, and black gas-and-ash plumes rose 600-1,500 m above the summit and drifted N, NE, E, and SE. The emissions were continuous most of the day on 14 May, during approximately 0517-1703 on 15 May, from about 0803 on 16 May to about 2217 on 19 May, and during the morning of 20 May. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater.

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

Etna (Italy) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Sezione di Catania - Osservatorio Etneo (INGV) reported continuing eruptive activity at Etna’s SE Crater and gas emissions at Bocca Nuova Crater, NE Crater, and Voragine during 12-18 May. Strombolian activity at SE Crater began in the late afternoon of 12 May, though weather clouds obscured visual observations. The activity was visually confirmed at 2030 during a break in the weather clouds. An eruption cloud drifted downwind and caused minor tephra fall along the SE flank reaching the towns of Petrulli and Zafferana Etnea. Two small lava flows descended the S and E flanks of SE Crater, as far as 0.8 km and 1.8 km, respectively.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Great Sitkin (United States) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin’s summit crater during 14-20 May. Small daily earthquakes were detected by the seismic network. Weakly elevated surface temperatures consistent with lava effusion were observed in clear satellite views during 16-19 May and steaming from the active vent was observed during 17-18 May. Weather clouds sometimes obscured views of the volcano. A 20 May radar image confirmed that lava was slowly advancing NE. 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)

Ibu (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 14-20 May. Daily gray, white-to-gray, or white-to-brown ash plumes rose as high as 1 km above the summit and drifted in various directions. Nighttime crater incandescence was visible in some webcam images. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening.

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

Karymsky (Russia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that, in general, moderate explosive activity continued at Karymsky during 8-15 May. Ash clouds were identified in satellite images drifting as far as 250 km SE and NE during 10-11 May. A thermal anomaly over the volcano was identified during 11-15 May; 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)

Kilauea (United States) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, from two vents along the SW margin of Halema’uma’u Crater, continued at variable levels during 14-20 May. Incandescence at both the N and S vents was visible during 13-16 May, and occasional spattering at the N vent occurred during the evening of 14 May. Small, sporadic, “gas-piston” events that produced spatter fountains and short lava flows began at the N vent at 2245 on 15 May. Five more “gas-piston” events and lava flows occurred the next morning at 0030, 0100, 0125, 0154, and 0243 on 16 May. Dome fountains overflowed the crater at 0440, and sustained high fountaining began at 0513. Fountain heights peaked at 300 m around 0600, then began to oscillate between 100 and 150 m. By 0610 the fountains were producing multiple lava flows that covered about 30-40 percent of the crater floor. The gas plume rose as high as 3 km and drifted WSW, away from populated areas. Sulfur dioxide emission rates were expected to be similar to those recorded during other moderate-to-high fountaining episodes, or around 50,000 tonnes per day (t/d). After over 10 hours of high fountains, that activity ceased at 1529 after an estimated 3.8 million cubic meters of lava had been erupted.

Incandescence from the lava flows was visible near the active vent region and along the N margin of the crater floor overnight during 16-17 May, and incandescence at both the N and S vents was visible during 16-20 May. 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 Hawaiian Volcano Observatory (HVO)

Lewotolok (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 14-20 May. Daily white steam-and-gas plumes rose as high as 100 m above the summit of the cone and drifted NW and W. A nighttime webcam image on 15 May showed incandescence at the summit. At 0751 on 19 May a gray ash plume rose around 500 m above the summit and drifted NW. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks.

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

Manam (Papua New Guinea) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Darwin Volcanic Ash Advisory Centre (VAAC) reported that an ash plume from Manam was identified in a satellite image at 1020 on 16 May drifting SE. The plume had dissipated by 1220.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Marapi (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity from Verbeek Crater at Marapi (on Sumatra) continued during 14-20 May, characterized by occasional dense gray ash plumes. The tallest ash plume rose 1.6 km above the crater rim at 0942 on 14 May and drifted NE. At 1939 on 15 May an ash plume rose 800 m and drifted E. Ash plumes at 0947 and 0954 on 17 May rose 1 km and 600 m above the crater rim, respectively, and drifted N and NE. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater.

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

Merapi (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 9-15 May. Seismicity remained at high levels. The SW lava dome produced 43 lava avalanches that traveled as far as 2 km SW down the Bebeng drainage, 18 that traveled as far as 2 km SW down the Krasak drainage, and 32 that traveled as far as 2 km W down the Sat/Putih drainage. Small morphological changes to the SW lava dome resulted from continuing effusion and minor collapses of material. The hottest temperature was 247.4 degrees Celsius, and the volume of the dome increased by 71,200 cubic meters to an estimated 3,996,800 cubic meters, based on webcam images and a 12 May drone survey. The size of the central dome had not changed; the highest temperature decreased three degrees to 218 degrees Celsius. 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 (Colombia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that eruptive activity at Nevado del Ruiz continued during 13-19 May. Seismic data indicated that events associated with fluid movement decreased in both number and intensity compared to the previous week. Seismicity associated with rock fracturing increased in both number and intensity compared to the previous week. The earthquakes were mainly located below Arenas Crater and the NE and SW flanks within 12 km at depths of 1-7 km. Seismicity indicating growth of the lava dome remained at low levels. Low-energy thermal anomalies on the crater floor were identified in satellite data, though weather clouds often obscured views. Significant sulfur dioxide emissions continued to be detected in satellite data. Gas-and-steam plumes rose as high as 500 m above the summit and drifted NW, WNW, and W. The only confirmed gas-and-ash plume during the week rose 700 m above the summit at 0837 on 17 May. The Alert Level remained at Yellow (the second level on a four-level scale).

Source: Servicio Geológico Colombiano (SGC)

Ontakesan (Japan) | 14 May-20 May 2025 | Continuing ActivityCite this Report

Escalating seismicity coupled with minor inflation at Ontakesan in January caused the Japan Meteorological Agency (JMA) to raise the Alert Level to 2 (on a scale of 1-5). Beginning in February deformation stagnated and only a few volcanic earthquakes were recorded by the seismic network through 20 May. The Alert Level was lowered to 1 at 1100 on 20 May.

Source: Japan Meteorological Agency (JMA)

Poas (Costa Rica) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported continuing gas-and-steam emissions that occasionally contained ash at Poás during 14-20 May. Activity generally decreased during the week, and deformation data indicated deflation. Vigorous gas-and-steam emissions continued at Boca A and incandescence was visible at night. Water that had pooled at Boca C continued to bubble; torrential rains during the beginning of the week continued to fill the crater. A moderate phreatic eruption at 0408 on 18 May generated a gas-and-steam plume with minor amounts of ash that rose 1 km above the crater rim and drifted SW. Sulfur dioxide emissions detected in satellite data were estimated to be 650 tons per day (t/d) on 18 May, 350 t/d on 19 May, and 598 t/d on 20 May. The volcano’s Alert Level remained at 3 (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest color on a four-color scale).

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

Reventador (Ecuador) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 13-20 May. Seismicity included 68-106 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Multiple daily ash-and-gas plumes rose 200-2,000 m above the crater rim and drifted in multiple directions. Webcams recorded multiple nightly instances of incandescent material descending the flanks as far as 1.1 km below the crater rim, specifically down the ESE and SE flanks during 17-18 May. Weather clouds occasionally obscured views. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Orange (the second highest level on a four-color scale).

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

Sangay (Ecuador) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported high levels of eruptive activity at Sangay during 13-20 May. The seismic network recorded 98-194 daily explosions. Ash-and-gas plumes were observed in webcam and/or satellite images on most days rising as high as 2 km above the summit and drifting in multiple directions. Weather clouds often obscured observations, especially during the first half of the week. Crater incandescence was sometimes visible during dark hours from 17 May through 20 May. Incandescent avalanches of material descended the SE flank 600 m during 18-19 May. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Yellow (the second highest level on a four-color scale).

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Secretaría de Gestión de Riesgos (SGR)

Semeru (Indonesia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 14-20 May, with multiple daily eruptive events recorded by the seismic network. Daily white-and-gray or gray ash plumes rose 300-1,000 m above the summit and drifted in multiple directions. The Alert Level remained at 2 (the second lowest level 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)

Sheveluch (Russia) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Kamchatkan Volcanic Eruption Response Team (KVERT) and the Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) reported that lava extrusion may have continued at Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 8-15 May. Thermal anomalies over the domes were identified in satellite images almost daily; weather clouds sometimes obscured views. 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.

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

Suwanosejima (Japan) | 14 May-20 May 2025 | Continuing ActivityCite this Report

The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 15-19 May. Incandescence was observed nightly in webcam images. No explosions were detected, though plumes from eruptive events rose 1 km above the crater rim. The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to be cautious within 1.5 km of the crater.

Source: Japan Meteorological Agency (JMA)