Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 31 May - 6 June 2023

Aira - Kyushu (Japan) : JMA reported ongoing activity at both Minamidake Crater and Showa Crater 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.

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.

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.

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.

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.

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).

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.

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. 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.

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 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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.