Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 7 September – 13 September 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 5-12 September. The seismic network recorded four eruptive events and seven explosions. Volcanic plumes rose as high as 2.3 km above the crater rim and ballistics were ejected as far as 1.3 km from the vent.

Ambae – Vanuatu : On 31 August the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that the cone in Ambae’s Lake Voui continued to produce emissions consisting of steam, volcanic gases, and possibly occasional ash.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) daily explosions generated ash plumes that rose up to 4 km (13,100 ft) a.s.l. and drifted in multiple directions. A thermal anomaly over the volcano was identified in satellite images during 3 and 5-8 September.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 6-13 September, though weather cloud cover prevented visual confirmation with webcam and satellite images. Seismicity was very low. Weakly-elevated surface temperatures consistent with lava effusion in the summit crater were identified overnight during 12-13 September.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 1, 3-4, and 7-8 September.

Kilauea – Hawaiian Islands (USA): HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-13 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. By 12 September about 111 million cubic meters of lava had been erupted from the vent since the current eruption began on 29 September 2021, raising the crater floor by 143 m.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 6-13 September. Daily white emissions rose as high as 500 m above the summit and drifted in multiple directions. During 7-8 and 10-11 September white-and-gray plumes rose as high as 700 m and 400 m above the summit, respectively, and drifted W and NW. Incandescence above the crater rim was visible in a webcam photograph captured on 13 September.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 2-8 September and seismicity remained at elevated levels. As many as 20 lava avalanches from the SW lava dome traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.7 km. No morphological changes to the SW and central lava domes were evident in photographs.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 6-13 September. Seismic tremor persisted. Weather clouds often prevented views of the volcano during the first part of the week, though one clear webcam view on 8 September showed a minor emission of ash or steam. Elevated surface temperatures were identified in satellite images during 10-12 September. A diffuse steam plume and new trace deposits of ash were visible in webcam images on 11 September.

Poas – Costa Rica : On 9 September OVSICORI-UNA reported that activity at Poás had increased since mid-August, characterized by notably increased seismicity. Seismic signals consisted of tremors with variable amplitudes and durations, prolonged harmonic tremors, and some long-period earthquakes with magnitudes greater than those recorded during 2022; there was no increase in low-frequency earthquakes. The energy of the seismicity had also dramatically increased in the previous few days. Sulfur dioxide emissions around the crater were mainly stable at 100 tons per day, though on a few occasions the concentrations were higher; about 300 tons per day was recorded during 17-18 August and higher than 500 tons per day was recorded on 2 September. The volume of water in Boca A lake had significantly increased during August 2021-September 2022, stabilizing at 1.4 million cubic meters between July and September with minor variations measured from week to week. Convection cells in the lake were more active and a new one formed in the N part of the lake (over the Boca C vent) since mid-August. OVSICORI-UNA stated that these data indicated disturbances to the shallow (less than 2 km) hydrothermal system and did not reflect an influx of magma. Fumarolic degassing and lake convection continued during 9-13 September.

Popocatepetl – Mexico : CENAPRED reported that there were 41-74 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 6-13 September. Explosions at 0343 and 0611 on 9 September produced ash plumes that rose as high as 2.5 km above the crater rim and drifted SE, and ejected incandescent material above the rim. Minor ashfall was reported in Atlixco, Puebla (23 km SE).

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported continuing eruptive activity at Rincón de la Vieja characterized by occasional small phreatic explosions. A small hydrothermal explosion at 1510 on 8 September produced a steam-and-gas plume that rose 500 m above the crater rim. During a clear observation period from 0500 to 0800 on 10 September scientists saw a continuous gas-and-steam plume and noted a hydrothermal explosion at 0640.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 September with a daily average of 44 explosions. Gas-and-ash plumes rose as high as 2.9 km above the summit and drifted NE, E, and SE. As many as 10 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).

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 6-13 September. Eruptive events at 0846 on 8 September, 0743 on 9 September, 0507 on 10 September, 0857 on 12 September, and 0524 on 13 September produced ash plumes that rose 300-700 m above the summit and drifted mainly W and SW. The Alert Level remained at 3 (on a scale of 1-4).

Semisopochnoi – Aleutian Islands (USA) : AVO reported ongoing low-level seismicity and occasional steam emissions at Semisopochnoi during 6-13 September. Satellite and webcam views were mostly obscured by weather clouds. Explosions were recorded during 12-13 September and ash emissions drifting 8 km SE at an altitude of 1.2 km (4,000 ft) a.s.l. were visible in satellite and webcam images.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 2-8 September. A daily thermal anomaly was identified in satellite images. Dome collapses produced hot avalanches and ash plumes that drifted 130 km NE and SE during 2 and 5-7 September. Plumes of re-suspended ash drifted 210 km ESE during 4-5 September.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 5-12 September. A total of 15 explosions produced eruption plumes that rose as high as 2 km above the crater rim. Large blocks were ejected 700 m from the vent. Crater incandescence was observed nightly, and volcanic tremor was occasionally recorded.

Yasur – Vanuatu : On 31 August Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest,” as defined by the Alert Level 2 status (the middle level on a scale of 0-4). Ash-and-gas emissions and loud explosions continued to be recorded, with bombs falling in and around the crater.

from WordPress https://ift.tt/gZpGdOq