Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 17 February 2021 – 23 February 2021

Aira – Kyushu (Japan) : JMA reported that during 15-22 February incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 16 February generated an eruption plume that rose 1 km above the crater rim and ejected bombs 1-1.3 km away from the crater. That same day the sulfur dioxide emission rate was extremely high, at 4,300 tons per day. An ash plume from an explosion at 2253 on 21 February rose 1.6 km and entered weather clouds. Large bombs were ejected 800-1,100 m away from the crater. The Alert Level remained at 3 (on a 5-level scale).

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12, 14-15, and 17 February that sent ash plumes to 2.1 km (6,900 ft) a.s.l. and drifted E and SE. Ashfall was reported in Severo-Kurilsk on 15 February and a thermal anomaly was identified in satellite images on 17 February. The Aviation colour Code remained at Orange (the second highest level

Fuego – Guatemala : INSIVUMEH reported that 4-12 explosions were recorded per hour during 17-23 February at Fuego, generating ash plumes as high as 1.1 km above the crater rim. Shock waves rattled buildings around the volcano. Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Ashfall was reported on most days in several areas downwind including Morelia (9 km SW), Panimaché I (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), and San Pedro Yepocapa (8 km NW). Notably, on 17 February ash plumes drifted as far as 50 km E, causing ashfall in local communities as well as in Guatemala City (city center is about 40 km ENE). Ash plumes drifted 40 km SW on 18 February. Curtains of old ash deposits remobilized by strong winds were observed during 19-21 February. Incandescent material was ejected 100-400 m above the summit during 19-22 February.

Ibu – Halmahera (Indonesia) : PVMBG reported that on most days during 17-23 February gray-and-white ash plume from Ibu were seen rising 200-800 m above the summit and drifting in multiple directions. Weather conditions sometimes hindered observations. The report stated that during 16-17 February there were a total of 88 eruptive events. 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 a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 February. The depth of the western part of the lake fluctuated between 215 and 218 m and the lake surface actively overturned at “plate” boundaries. The sulfur dioxide emission rate was elevated at 1,000 tons/day on 19 February.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 16-23 February; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 50-500 m above the summit and drifted E and SE. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 12-18 February. The 2021 lava dome volume was an estimated 397,500 cubic meters on 17 February, with a growth rate of about 25,200 cubic meters per day; it was 258 m long, 133 m wide, and 30 m high. The summit lava dome was an estimated 426,000 cubic meters, with a growth rate of about 10,000 cubic meters per day; it was 160 m long, 120 m wide, and 50 m high. Seismicity was less intense than the previous week. Electronic Distance Measurement (EDM) data showed no notable deformation. PVMBG noted that foggy conditions often prevented visual observations during 18-23 February, though sometimes white emissions were observed rising up to 400 m above the summit. 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.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 71 explosions at Sabancaya during 15-21 February. Gas-and-ash plumes rose as high as 3.2 km above the summit and drifted in multiple directions. Ten 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.

Semeru – Eastern Java (Indonesia) : PVMBG reported that the eruption at Semeru continued during 17-23 February, though weather conditions often prevented visual confirmation. At 0601 on 17 February an ash plume rose 300 m and drifted N. A white-and-gray ash plume rose 100 m and drifted N, NE, and E on 18 February. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 4 km in the SSE sector.

Semisopochnoi – United States : AVO reported that no significant activity at Semisopochnoi was recorded after several ash deposits were visible in satellite images during 6-7 February. On 19 February the Aviation colour Code and the Volcano Alert Level were lowered to Yellow/Advisory, respectively.

Sheveluch – Central Kamchatka (Russia) :KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 12-19 February. 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 17-23 February, though weather conditions sometimes prevented visual confirmation. White plumes rose as high as 1 km above the summit and drifted in multiple directions. On 21 February pyroclastic flows traveled as far as 2 km down the E and SE flanks. 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.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Ontake Crater during 12-19 February. These events produced ash plumes that rose as high as 1.5 km above the crater rim and ejected bombs 300 m away from the crater. The Alert Level remained at 2 (on a 5-level scale).

Whakaari/White Island – North Island (New Zealand) : GeoNet reported that beginning around 0220 on 19 February a series of short-lived, low-energy steam explosions at Whakaari/White Island were recorded for about 100 minutes by local seismic and acoustic instruments. Webcam images were dark due to the time of day; no trace ash deposits were visible. Tremor had begun around 2100 the night before and then ceased at 0550 when the steam explosions ended. Visual observations and gas flux measurements taken during an overflight on 18 February showed no changes compared to the previous month. The Volcanic Alert Level remained at 1 and the Aviation colour Code remained at Green.

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