Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 21 June - 27 June 2023

Ahyi - Mariana Islands (USA) : Unrest at Ahyi Seamount possibly continued during 21-27 June. One small hydroacoustic signal coming from the direction of the seamount was detected by pressure sensors on Wake Island (2,270 km E) during 23-24 June. Data from the sensors on Wake Island stopped transmitting at 0414 on 24 June though no signals were detected by sensors on Saipan during the rest of the week. No surface activity was visible in satellite images.

Aira - Kyushu (Japan) : JMA reported ongoing activity at both Minamidake Crater and Showa Crater (Aira Caldera’s Sakurajima volcano) during 19-26 June. Very small eruptive events occasionally occurred at Minamidake and incandescence was observed at night. An explosion at Showa at 0438 on 22 June produced an ash plume that rose 600 m above the crater rim and drifted E and ejected blocks 500-800 m from the vent. Sulfur dioxide emissions averaged 1,400 tons per day on 22 June.

Cotopaxi - Ecuador : IG reported that moderate eruptive activity continued at Cotopaxi during 20-27 June. Several gas-and-ash emissions rose as high as 900 m above the summit and drifted S, SW, and W during 21-22 June. During 22-23 June gas plumes with low amounts of ash rose less than 200 m above the summit and drifted SW. Additional gas-and-steam emissions during 23-26 June rose as high as 500 m above the summit and drifted to the S and SW. Weather clouds often prevented direct observations.

Ebeko - Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 15-22 June. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 16-17, 20, and 22 June generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l. and drifted NE and SE. A thermal anomaly was identified in satellite images on 22 June; weather clouds obscured views on the other days.

Fuego - South-Central Guatemala : INSIVUMEH reported that 1-6 explosions per hour were recorded at Fuego during 21-27 June, generating daily ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as 30 km S, SW, W, and NW. The ash plumes were described as dense during 22-23 June and mostly gas with diffuse ash during 24-26 June. The explosions occasionally triggered weak-to-moderate avalanches that descended multiple ravines. Minor ashfall was reported on all days, except 21 June, in areas downwind including La Soledad (7 km N), El Porvenir (8 km SE), Panimanché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Yucales (12 km SW), Finca Palo Verde (10 km WSW), Sangre de Cristo (8 km W), and Yepocapa (9 km WNW). Lahars descended the Ceniza (SSW) ravine on 21 June and the El Jute (ESE) ravine on 23 June.

Great Sitkin - Andreanof Islands (USA) : AVO reported that slow lava effusion likely continued at Great Sitkin during 20-26 June. Minor seismicity was ongoing, and a few small earthquakes were recorded during 25-26 June. Elevated surface temperatures were identified in satellite images during 20-21 June and minor steaming was visible in satellite and webcam views during 25-27 June; weather clouds sometimes obscured webcam and satellite views on the other days.

Karangetang - Sangihe Islands : PVMBG reported that dense white gas-and-steam plumes from Karangetang were visible rising as high as 150 m and drifting in multiple directions during 21-27 June. Webcam images published in the reports on 21, 25, and 27 June showed incandescence at Main Crater (S crater) and from material on the flanks of Main Crater.

Lewotolok - Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 21-27 June. Emissions mainly consisted of white steam-and-gas plumes that rose as high as 800 m above the summit and drifted W and NW; white-and-gray ash plumes rose as high as 800 m above the main crater and drifted W and NW during 22-23 June. Incandescence was visible at the summit during 24-26 June, and a webcam image taken at 2257 on 25 June showed incandescent ejecta at the summit.

Merapi - Central Java : BPPTKG reported that the eruption at Merapi (on Java) continued during 16-22 June and seismicity remained at elevated levels. The SW lava dome produced 116 lava avalanches that traveled as far as 1.8 km down the SW flank (upstream in the Bebeng and Boyong drainages). Morphological changes to the SW lava dome were due to continuing collapses of material.

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 20-27 June and was characterized by gas, steam, and ash emissions, and variable seismic activity. The number of seismic events related to fluid movement, emissions, and rock fracturing fluctuated throughout the week; seismicity was highest at the beginning of the week and notably high during 22-23 June with the most intense seismicity recorded since the current period of elevated activity began on 24 March. Earthquakes occurred at distances of 1-8 km from Arenas crater at depths of 1-6 km. A period of continuous ash emissions in the afternoon of 20 June was visible in webcam images. Ashfall was reported in Manizales. Ash emissions on 21 June rose as high as 1.3 km above the crater rim, drifted WNW, and continued to rise to as high as 4 km above the summit. Incandescence from the crater was visible coincident with pulsating ash emissions during 20-23 June. Gas, steam, and ash plumes rose as high as 1.8 km and drifted NW during 24-27 June. Minor ashfall was reported in the municipalities of Villamaría (28 km NW) and Manizales (28 km NW) on 22 and 25 June respectively. The Alert Level was lowered to Yellow, Level III (the second level on a four-level scale) on 27 June. SGC noted that monitoring data was more stable in recent weeks; earthquake magnitudes were overall lower, the locations were more random, and the patterns did not indicate magma movement. Additionally, thermal anomalies at the lava dome were less intense, ash emissions had decreased, and gas emissions remained relatively stable.

Popocatepetl - Mexico : CENAPRED reported that ongoing activity at Popocatépetl during 20-27 June included 14-66 daily steam-and-gas emissions, sometimes containing minor amounts of ash. Seismic activity was characterized as daily periods of high-frequency events and variable amplitude tremors, volcano-tectonic earthquakes (2235 and 2329 on 21 June, 1520 and 2134 on 26 June), 15 minutes of low-amplitude harmonic tremor during 21-22 June, and both minor and moderate explosions. Small bursts of incandescent ejecta from the crater were observed during the night of 20 June. Minor ashfall was reported in Cuernavaca (66 km W), state of Morelos, during 20-21 June. At 0312 on 22 June a moderate explosion ejected incandescent ballistic material as far as 1.5 km from the crater and generated an ash plume that rose 2 km above the crater. Minor amounts of fell in Hueyapan (16 km SSW), state of Morelos, during 21-22 June. Minor explosions at 0405 and 0745 on 23 June produced ash plumes that rose 500 m; the first explosion ejected incandescent material short distances from the crater. Ashfall was reported in the municipalities of Ozumba (19 km W), Tepetlixpa (21 km W), Juchitepec (29 km WNW), and Amecameca (19 km NW), all within the State of México. A minor explosion was recorded at 0809 on 27 June.

Reventador - Ecuador : IG reported that the eruption at Reventador was ongoing during 20-27 June. Seismicity was characterized by 7-30 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Weather clouds often hindered visual observations, though crater incandescence was visible on most nights and early mornings, and from the S-flank lava flow on 21-22 June. During 21-23 June ash emissions rose as high as 1 km above the crater and drifted to the NE, W, and NW. During 23-26 June gas-and-ash emissions rose as high as 1 km above the crater and drifted to the W and NW.

Rincon de la Vieja - Costa Rica : OVSICORI-UNA reported that the level of the water lake in Rincón de la Vieja’s summit crater declined during 30 May-21 June based on drone footage. A small phreatic eruption occurred at 0607 on 22 June. Several small phreatic eruptions were recorded overnight during 25-26 June. A small event at 0547 on 26 June produced a steam-and-gas plume that rose 1.5 km above the crater rim. Another small event at 0308 on 27 June produced a gas-and-steam plume that rose more than 1 km, though weather clouds and darkness obscured views.

Santa Maria - Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa Maria’s Santiaguito lava dome complex continued during 20-27 June, with effusion of lava flows, explosions, and avalanches. Dome growth sometimes produced avalanches and short pyroclastic flows that traveled down the S, SW, and W flanks. Weak and moderate explosions were recorded daily. Explosions also triggered dome collapses, resulting in weak and moderate debris avalanches that descended the flanks in many directions. Incandescence at the crater and along lava flow margins was visible during most nights and early mornings. During 20-21 June ash-and-gas plumes rose 800 m and drifted W and SW. On 23 June a lahar descended the Río Cabello de Ángel, a tributary of the Nimá I and Samalá rivers on the E flank. The lahar consisted of a mixture of fine volcanic material, water, volcanic blocks up to 1 m in diameter, and tree trunks and branches.

Semeru - Eastern Java : PVMBG reported that the eruption at Semeru continued during 21-27 June. White-and-gray or white-to-brown ash plumes of variable densities generally rose as high as 1 km above the summit and drifted in multiple directions; emissions were not visible on 25 June, a partly cloudy day. A webcam image showed incandescent material at the summit and on the flanks at 0145 on 23 June. According to Info Semeru (a local news source) a pyroclastic flow traveled 5 km down the SE flanks at 1910 on 26 June. PVMBG reported that at the same time a gray-to-brown ash plume rose 1.5 km above the summit and drifted NE and E, and a webcam image showed incandescent material descending the flank.

Sheveluch - Central Kamchatka (Russia) : KVERT reported that the eruption at Sheveluch was ongoing during 15-22 June. Intense fumarolic activity at the active crater was likely associated with growth of the lava dome. A thermal anomaly over the active crater area was identified in satellite images during 16, 18-19, and 22 June.

Suwanosejima - Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima's Ontake Crater continued at low levels during 21-27 June. At 1521 on 25 June an eruptive event produced an ash plume that rose 1.3 km above the crater rim and drifted to the N, and ejected a large block 100 m from the crater. At 0036 on 27 June an ash plume rose 1.2 km and drifted N, followed by another at 0909 that rose 1.8 km and drifted E.