Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 24 March 2021 – 30 March 2021

Aira – Kyushu (Japan) : JMA reported that during 22-26 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 25 March produced an eruption plume that rose 1.4 km above the crater rim. On 27 March at 0236 an eruption generated an ash plume that rose 2.5-4 km above the crater rim and drifted NW, resulting in a large amount of ashfall in Kagoshima City (about 10 km W). Volcanic bombs were ejected 1-1.3 km away from the crater. An eruption on 29 March at 1557 produced an eruption plume that rose 2.2 km above the crater rim and drifted SE, resulting in a pyroclastic flow down the SE flank and ashfall in Kagoshima City and the Kagoshima Prefecture. An explosion on 30 March at 0433 generated an ash plume that rose 2.7 km above the crater and drifted E, ejecting bombs 600-900 m from the crater. Ashfall was again reported in Kagoshima City. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 24-30 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. 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) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 19, 21, and 24-25 March that sent ash plumes up to 2.5 km a.s.l. (8,200 ft) and drifted in different directions. Ashfall was reported in Severo-Kurilsk on 24 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego – Guatemala : INSIVUMEH reported that 6-11 explosions per hour were recorded during 24-30 March at Fuego, generating ash plumes that rose to 4.7 km (15,000 ft) a.s.l. and drifted W, NW, and SW as far as 10-15 km. Shock waves rattled buildings near the volcano. Block avalanches descended the Seca (W), Ceniza (SSW), and Trinidad (S) drainages, often reaching vegetated areas. Ash plumes from explosions rose to 4.8 (16,000 ft) km a.s.l. and drifted N and NE on 25 March and W on 27 March far as 15-20 km, resulting in ashfall in Morelia (9 km SW), Panimache (8 km SW), Yucales (12 km SW), Sangre de Cristo (8 km WSW), Yepocapa (8 km NW), La Soledad (11 km N). Block avalanches descended the Taniluyá (SW), Las Lajas (SE), and Honda drainages, in addition to those affected on 24 March. Weak crater incandescence was observed at night and in the early morning during 26 March. Incandescent material was ejected 100-200 m above the summit on 28 March, accompanied by ash plumes that rose to 4.8 km a.s.l. and resulted in ashfall in Palo Verde, Panimaché II, Sangre de Cristo, Yepocapa, and El Porvenir (8 km ENE).

Ibu – Halmahera (Indonesia) : PVMBG reported that on 25 March at 1814 a gray ash plume from Ibu rose to 2.3 km (7,500 ft) a.s.l. and drifted W. White-and-gray emissions rose 200-1,000 m above the crater drifting N, S, E, and W during 25-26, 28, and 30 March. 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.

Kilauea – Hawaiian Islands (USA) : HVO reported that the W vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 24-30 March. Lava flowed from the main vent into the lake through two crusted-over channels and submerged inlets, the former of which occurred during 24-25 March. The total depth of the lake measured about 224 m and lava continued to circulate in the W part; the E half of the lake remained solidified, expanding toward the W. The sulfur dioxide emission rate was 950 and 650 tons/day on 22 and 26 March, respectively. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the flank eruption on Klyuchevskoy’s lower NW flank had ended on 20 March. Weak incandescence from the cinder cone and lava flows visible in webcam images reflected cooling. The temperature of the thermal anomaly identified in satellite data continued to decrease. On 24 March the Aviation colour Code was lowered to Green (the lowest level). According to satellite data, a plume of resuspended ash extended for 72 km E of the volcano on 25 March; no eruption was reported. On 25 March the Aviation colour Code was briefly increased to Orange (the second highest level on a four-colour scale) and was lowered to Green by 26 March.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 24-30 March. Daily gray-and-white ash plumes rose as high as 800 m above the summit and drifted in different directions. Incandescent material was ejected 500 m above the summit on 23, 27, and 30 March, and 300 m above the summit on 25 March. On 26 and 28 March incandescence was observed up to 100 m above the summit, accompanied by incandescent ejecta as far as 350 m to the SE. The eruptive events were accompanied by rumbling and banging sounds. 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 dome just below Merapi’s SW rim continued to grow and shed material down the flank during 19-25 March. The 2021 lava dome volume was an estimated 949,000 cubic meters on 25 March, with a growth rate of about 13,300 cubic meters per day. The Mount Merapi Selo Observation Post reported a white gas-and-steam plume rose 500 m above the crater on 25 March at 1430. Four pyroclastic flows traveled a maximum of 1.8 km down the SW flank, three of which occurred on 27 March at 0602, 0603, and 0631. An ash plume caused by a pyroclastic flow rose 3.5 km (12,000 ft) a.s.l. and drifted SW for about 1.3 km on 27 March at 1758 on, according to a ground observer. Incandescent avalanches, recorded 104 times, traveled as far as 1.2 km down the SW flank and twice down the SE flank as far as 400 m. The summit lava dome measured 65 m tall, similar to the previous week. On 30 March there were 33 incandescent avalanches observed traveling up to 1 km down the SW flank, one of which continued up to 1.5 km. One incandescent avalanche was observed from the lava dome. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 50-1,200 m above Raung’s summit during 24-29 March. Ash plumes drifted in different directions. 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.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 24-30 March; adverse weather conditions sometimes prevented visual confirmation. Seismicity was characterized by 49-80 daily explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes, as well as signals indicating emissions. Gas, steam, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1.4 km above the summit crater and drifted mainly W, NW, SW. Crater incandescence and incandescent blocks rolling down the NE flank were observed nightly and accompanying explosions during 24-25 March.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 90 explosions at Sabancaya during 22-28 March. Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted SW, W, N, and NW. Six thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected in areas N of Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 12-km radius.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 24-30 March. Seismicity was characterized by 1-8 daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds and rain often prevented visual observations of the volcano, though based on the Washington VAAC reports, daily ash plumes were noted rising as high as 2.1 km above the summit and drifting in different directions. Images shared by the Red de Observadores Volcánicos (ROVE) (Network of Volcanic Observers) showed gas-and-steam emissions reaching 900-1,000 m above the crater drifting N on 26-27 March. A seismic station recorded occasional debris flows during 24-30 March. No ashfall was reported by residents.

Santa Maria – Guatemala : INSIVUMEH reported that during 24-30 March weak explosions at Santa María’s Santiaguito lava-dome complex generate ash plumes that rose to 2.8-3.4 km (9,000 ft-11,000 ft) a.s.l. and drifted W, NE, SW. Collapses of blocky lava from the Caliente dome sent avalanches on the S and SW flank of the Caliente dome, causing minor ashfall around the volcano. Block avalanches were also observed on the E and S flanks; ashfall was reported in San Marcos (8 km SW) and Loma Linda Palajunoj (6 km WSW) on 25 and 27 March. Minor pyroclastic flows were reported on 28 March.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that lava dome growth at Sheveluch continued during 20-26 March, accompanied by strong fumarolic activity, incandescence, and block avalanches. Satellite imagery showed a thermal anomaly over the lava dome all week, except on 22 and 25 March due to cloud cover. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 24-30 March. The Darwin VAAC reported that an eruption on 28 March generated an ash plume that rose to 3.4 km a.s.l. (11,000 ft). Explosions on 29 March at 0024 and 1035 produced ash plumes that rose to 3.5 km a.s.l. (11,500 ft) and drifted NNE and ESE, respectively. 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) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 23-27 March, expanding to the N and S. Gas-and-steam continued to rise from the top of the dome, as well as along the contact with the pre-existing 1979 dome. On 23 March at 1030 the monitoring network recorded a swarm of small low-frequency seismic events that lasted about 45 minutes, which was likely associated with magma movement beneath the dome. Starting at 1653 the monitoring network also began to detect volcano-tectonic (VT) earthquakes, some of which have been felt by nearby communities, including Fancy, Owia, and Sandy Bay. On 26 March the period of elevated VT earthquakes stopped; only small, low frequency events associated with the growth of the lava dome were recorded. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the seismic network for Suwanosejima’s Ontake Crater detected a total of 17 explosions during 19-26 March. These events produced eruption plumes that rose as high as 1.2 km above the crater rim, drifting S, W, and SW, and ejected bombs as far as 500 m away from the crater. Incandescence from the crater was occasionally visible at night. On 30 March at least 18 explosions were detected, generating ash plumes that rose 600-1,500 m above the crater drifting E, SE, and NE and ejecting material as far as 800 m S of the crater. On 31 March the Alert Level was raised to 3 (on a 5-level scale).

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