Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 9 June – 15 June 2021

Aira – Kyushu (Japan) : JMA reported that during 7-14 June incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. The sulfur dioxide emission rate was low at 900 tons per day on 9 June. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Asosan – Kyushu (Japan) : Volcanic tremor amplitude had increased at Asoson on 2 May, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5). The amplitude remained high through 10 May, and then gradually decreased. On 9 June the Alert Level was lowered to 1 and the public was warned of an increased risk within 1 km of Nakadake Crater.

Bulusan – Luzon (Philippines) : At 2300 on 12 June PHIVOLCS stated that unrest at Bulusan had again increased, with a total of 95 weak volcanic earthquakes occurring during the previous 17 hours. Diffuse white steam plumes rose from the SW vents. Inflation of the upper flanks first recorded on 6 March in tilt data was sustained. GPS data indicated short-term inflation starting in May, though the long-term pattern since May 2019 showed overall deflation. The seismic unrest was likely due to shallow hydrothermal activity; the Alert Level remained at 1 and the public was reminded not to enter the 4-km-radius Permanent Danger Zone (PDZ).

Dukono – Halmahera (Indonesia) : PVMBG reported that during 8-10 and 14 June ash plumes from Dukono rose 100-600 m above the summit and drifted NW, NE, E, and SW. Weather conditions prevented visual observations during 10-13 and 15 June. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 4-6 and 9-10 June produced ash plumes that rose as high as 2.6 km (8,500 ft) a.s.l. and drifted in different directions. A thermal anomaly was identified in satellite images on 10 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu – Halmahera (Indonesia) : PVMBG reported that during 9-15 June gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted mainly N and E. Rock avalanches were recorded during 11-13 June, though they were not visually confirmed. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Kadovar – Papua New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 12 June ash plumes from Kadovar rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted W.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 3 and 8-10 June. Ash plumes drifted 40 km NE during 6-8 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kerinci – Indonesia : PVMBG reported that at 1730 on 13 June an ash plume from Kerinci rose 700 m above the summit and drifted W. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone.

Krysuvik-Trolladyngja – Iceland : The fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 9-15 June. Lava fountaining from the fifth vent was periodically visible, and lava from the crater flowed in tubes as well as on the surface. Sections of the cone’s rim periodically collapsed, sending lava cascading down the flanks. A notable event on 10 June began with lava rising in the crater and vigorously splashing above the rim; an overflow began with several streams of lava that quickly merged into a wide, fast-moving “lava fall” that broke parts of the crater rim. On 13 June lava overflowed the southern area of Geldingadalur valley and flowed over hiking trail “A”, causing authorities to restrict access to the eruption site that day due to safety reasons. The narrow lava flow then turned E and entered the Nátthaga valley from the W wall and joined the larger advancing flow. Lava in Nátthaga continued to get closer to Highway 427 (Suðurstrandarvegur) to the S, and buried fiber optic communication cables. The leading edge of the flow ignited the vegetation, causing small fires. The Aviation colour Code remained at Orange due to the lack of ash and tephra emissions, though IMO warned of the potential for lapilli and scoria fallout within a 650 m radius of the active vent. Authorities warned of increased gas emissions hazards.

Langila – New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 13-14 June ash plumes from Langila rose 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted W and WNW.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that white-and-gray plumes from Lewotolok rose as high as 800 m and drifted W and E almost daily during 9-15 June. Incandescent material was ejected 200-500 m SE during 8-10 June. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the lava domes just below Merapi’s SW rim and in the summit crater remained active during 4-10 June. The SW rim lava-dome volume was an estimated 1.3 million cubic meters on 8 June, and continued to shed material down the flank. A total of 12 pyroclastic flows traveled a maximum of 1.6 km down the SW flank and 1 km SE. Incandescent avalanches, recorded 52 times, traveled as far as 2 km down the SW flank and three times went 600 m SE. The volume of the summit lava dome was 2.1 million cubic meters on 8 June. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the summit.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that seismic activity at Semisopochnoi was low during 9-15 June and no eruptive activity was detected in infrasound or satellite data. Elevated surface temperatures and steaming from the active vent were occasionally identified in satellite images. Sulfur dioxide emissions were visible in satellite data during 11-13 June. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 3, 6, and 8-10 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that avalanches of material from Sinabung’s summit lava dome were occasionally recorded during 11-13 June but not visually observed due to weather conditions. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) reported that seismicity at Soufrière St. Vincent (often simply referred to as “La Soufriere”) had remained low since the last episode of ash venting on 22 April. Some daily earthquakes were recorded during 7-15 June. Steam-and-gas plumes rose from a few areas inside the crater and thermal anomalies persisted. The crater was observed and photographed during 11-12 June; observers saw no signs of lava domes. The Alert Level remained at Orange.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that 28 explosions at Suwanosejima’s Ontake Crater produced eruption plumes that rose as high as 2.4 km above the crater rim during 4-11 June. Large volcanic bombs were ejected 500 m from the crater. Ashfall was reported in Toshima village (4 km SSW). Crater incandescence was visible nightly. The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater.

Taal – Luzon (Philippines) : PHIVOLCS reported that unrest at Taal continued during 9-15 June. Sulfur dioxide emissions reached the highest levels ever detected at the volcano, averaging 9,911 tonnes/day on 10 June. Peak measurements coincided with periods of vigorous upwelling at the Main Crater Lake; the upwelling was continuous from 1800 on 9 June to 1000 on 10 June, producing steam plumes that rose 1.5 km and drifted mainly NW. Residents of barangays Banyaga, Bilibinwang, and Subic Ilaya (Municipality of Agoncillo, Batangas Province) reported throat irritations and observed sudden drying or die off of crops, plants, and trees after a period of rain. Averages on the other days were also elevated at 1,725-5,837 tonnes/day, and steam plumes from periods of lake upwelling rose 1-1.5 km and drifted NE, NW, and SW. Low-level background tremor that had begun at 0905 on 8 April continued. During 13-14 June the seismic network recorded 13 periods of volcanic tremor with durations from 1 to 270 minutes. During 14-15 June the network recorded 221 volcanic earthquakes, 29 low-frequency earthquakes, and 192 periods of volcanic tremor with durations from 1 to 135 minutes. PHIVOLCS noted the continuing state of elevated unrest, reminding the public that the Alert Level for Taal remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater, Daang Kastila fissure (along the walking trail), and boating on Taal Lake was strictly prohibited.

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