Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 24 May - 30 May 2023

Aira - Kyushu (Japan) : JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 22-29 May. Crater incandescence was observed nightly at Minamidake, and during 25-29 May at Showa; incandescence at Showa had not been visible since 5 March. The only eruptive event at Showa during this period was at 1125 on 22 May, when material was ejected 200-300 m from the crater and an ash plume rose 1.5 km above the crater rim. At 0610 on 24 May an explosion at Minamidake ejected material 300-500 m from the crater and generated an ash plume that rose 1.5 km above the crater and drifted to the SW. An eruptive event at 1327 on 25 May produced an ash plume that rose 2.3 km. On 26 May two explosions (at 0647 and 1441) and an eruptive event (1311) generated ash plumes that rose as high as 1.6 km and drifted N and S. The explosion at 1441 ejected blocks 500-700 m from the vent. An explosion at 1520 on 28 May ejected material 600-900 m from the crater and produced an ash plume that rose 2.3 km from the summit .

Bezymianny - Central Kamchatka (Russia) : KVERT reported that eruptive activity at Bezymianny was generally characterized by lava effusion, gas-and-steam emissions, lava dome incandescence, and hot avalanches that traveled down the flanks during 24-30 May. A persistent thermal anomaly was identified daily in satellite data.

Cotopaxi - Ecuador : IG reported that moderate eruptive activity continued at Cotopaxi during 23-30 May. Seismic activity was mainly characterized by long-period earthquakes and tremors associated with emissions that occurred almost daily; a total of three volcanic-tectonic earthquakes were recorded during the week. Weather clouds often hindered views, though gas-and-steam emissions were visible daily. During 23-24 May ash-and-gas emissions rose as high as 1 km above the summit and drifted W. On 26 May a period of continuous ash emissions was recorded with the plumes rising as high as 2 km above the summit and drifting NW and W. On 30 May ash plumes rose 1.2 km and drifted W; ashfall was reported in the Pastocalle parish of Latacunga canton (Cotopaxi Province).

Dukono - Halmahera : PVMBG reported that Dukono continued to erupt during 24-30 May. Daily explosions were recorded by the seismic network. White-and-gray plumes of variable densities rose as high as 450 m above the summit and drifted E.

Ebeko - Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 18-25 May. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 23-25 May generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l. and drifted S, SE, and E. A thermal anomaly was identified in satellite images on 24 May and ash plumes were visible drifting 75 km SE on 25 May.

Fuego - South-Central Guatemala : INSIVUMEH reported that 1-3 weak explosions per hour were recorded at Fuego on most days during 24-30 May. The explosions generated ash plumes that rose between 450-750 m above the summit. The plumes drifted as far as 10 km SE on 26 and 30 May, 10 km SE and S on 27 May, and 6 km SE and S on 29 May. Ashfall was reported in El Zapote (10 km SSE), La Rochela (8 km SSW), and San Andrés Osuna (12 km SSW) on 26 and 30 May. Minor crater incandescence was occasionally visible during some nights and early mornings. Minor lahars descended the Ceniza drainage on 25 and 28 May and a weak-to-moderate lahar descended the Santa Teresa on 29 May. Both lahars consisted of hot volcanic material, branches, tree trunks, and volcanic blocks as large as 1.5 m in diameter.

Great Sitkin c- Andreanof Islands (USA) : AVO reported that slow lava effusion continued at Great Sitkin during 23-30 May. A sequence of small low-frequency earthquakes was recorded for several hours on 23 May but did not result in any observed change in eruptive activity. Several small earthquakes were recorded daily during 24-27 May. No changes to the flow field were identified in satellite images acquired on 23, 27, or 28 May.

Lewotolok - Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 24-30 May. Daily white-to-gray plumes of variable densities rose as high as 800 m above the summit and drifted E, NE, N, and NW. At 2037 on 27 May a webcam image showed an explosion of incandescent material above the summit. At 0613 on 29 May a dense gray-and-black ash plume rose 800 m above the summit and drifted NE and E.

Merapi - Central Java : BPPTKG reported that the eruption at Merapi (on Java) continued during 19-25 May and seismicity remained at elevated levels. The SW lava dome produced 236 minor lava avalanches that traveled as far as 2 km down the SW flank (upstream in the Bebeng and Boyong drainages). Morphological changes to the SW lava dome due to continuing collapses of material were evident in webcam and drone images. Based on a 17 May drone survey, the SW dome volume was an estimated 2,372,800 cubic meters and the dome in the main crater was an estimated 2,337,300 cubic meters.

Reventador - Ecuador : IG reported that the eruption at Reventador was ongoing during 23-30 May. Seismicity was characterized by 28-43 daily explosions, long-period earthquakes, harmonic tremors, and emission-related tremors. Daily gas-and-ash emissions rose as high has 1 km above the crater and drifted SW, W, NW, and NE. On most nights incandescent blocks were seen rolling 500-1,000 m down the flanks; incandescence at the crater and on the upper flanks was also periodically visible.

San Miguel - Eastern El Salvador : MARN reported that seismicity at San Miguel was detected on 23 May and remained elevated. At 1647 on 27 May an explosion generated a gas-and-ash plume that rose 700 m; seismicity decreased afterwards. Sulfur dioxide emissions were as high as 400 tons per day that same day based on measurements from an instrument located on the W flank, and then decreased to 268 and below 100 tons per day on 28 and 29 May, respectively.

Sangay - Ecuador : IG reported a high level of activity at Sangay during 23-30 May, though weather clouds sometimes prevented visual observations. There were 304-600 daily explosions recorded by the seismic network; no data was reported on 28 May. Ash plumes were seen in webcam images and reported by the Washington VAAC almost daily. On 23 May incandescent material extending 1.8 km down the SE flank was visible in webcam images. On 24 May pyroclastic flows descending 200 m were visible in between somewhat-dense weather clouds. An ash plume rose 300 m and drifted W. On 25 May ash plumes rose as high as 2 km and drifted NE and SE. Ash emissions were visible in webcam images at 1734 and were continuous for a period of time. Crater incandescence was visible overnight during 25-27 May and ash plumes that rose 500-800 m drifted SW and NW during 26-27 May. Incandescence from the lava flow on the SE flank was noted overnight during 28-29 May. The VAAC reported that at 0610 on 29 May ash plumes were visible in satellite images drifting W at 30,000 ft a.s.l., or 3.9 km above the summit, and drifting N at 40,000 ft a.s.l., or 6.9 km above the summit. Several pyroclastic flows descending the SE flank were visible in webcam images at 0615. At 1730 ashfall was reported in Cebadas Parish (Chimborazo province).

Semeru - Eastern Java : PVMBG reported that the eruption at Semeru continued during 24-30 May. Volcano Observatory Notices for Aviation (VONAs) that described ash emissions were issued throughout the week. Daily sometimes-dense ash plumes rose as high as 1 km above the summit and drifted S, SW, W, and N.

Sheveluch - Central Kamchatka (Russia) : KVERT reported that the eruption at Sheveluch was ongoing during 18-25 May. A thermal anomaly over the active crater and Karan lava dome area was identified in satellite images all week. Intense fumarolic activity at the active crater was likely associated with dome growth.

Stromboli - Aeolian Islands (Italy) : INGV reported ongoing activity at Stromboli during 22-28 May. The Strombolian activity was centered at two vents in Area N (one each at craters N1 and N2), within the upper part of the Sciara del Fuoco, and from four vents in Area C-S (South-Central Crater) in the crater terrace. Low-intensity explosions at a rate of 3-7 per hour from Area N ejected mainly coarse material (bombs and lapilli) from N2, with mainly ash emissions from N1 as high as 80 m above the vents. Low- to medium-intensity explosions at an average rate of 2-7 per hour from the two vents in sector S2 (Area C-S) ejected a mix of coarse material and ash. During 27-28 May intense gas emissions at S1 sometimes contained coarse material. Intense spattering and occasionally weak explosions of coarse material was observed in sector C (Area C-S).

Suwanosejima - Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 22-29 May and incandescence at the crater was visible nightly. Daily ash plumes from eruptive events rose as high as 1.6 km above the crater rim and drifted in multiple directions. Blocks were ejected as far as 300 m from the crater. At 2245 on 23 May an explosion generated an ash plume that rose 600 m and drifted S.

Taupo - North Island (New Zealand) : GeoNet reported that earthquake activity and ground deformation at Taupo declined during January-April and returned to background levels in May. Unrest at the volcano started in early May 2022; during the year there were just over 1,800 earthquakes located beneath the volcano along with ground deformation both on the lake floor and around the lake.