Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 14 July – 20 July 2021

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 13-19 July ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted NW, N, NE, and ESE. 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 10-14 July produced ash plumes that rose as high as 3 km (10,000 ft) a.s.l. and drifted E. A thermal anomaly was identified in satellite images on 10 and 12 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego – Guatemala : INSIVUMEH reported that 5-15 explosions per hour were recorded during 13-20 July at Fuego, generating ash plumes as high as 1.1 km above the crater rim and shock waves that often rattled buildings around the volcano. Ash plumes mostly drifted 10-20 km NW, W, and SW and caused daily ashfall in several areas downwind, including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Finca Palo Verde, Sangre de Cristo (8 km WSW), and San Pedro Yepocapa (8 km NW). Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Explosions ejected incandescent material 100-400 m above the summit during 13-19 July.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that ash plumes from Karymsky were identified in satellite data drifting 80 km NW, NE, and ESE during 8-11 and 15 July. A thermal anomaly was visible during 8 and 10-13 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

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 14-20 July. Lava fountaining and overflows from the fifth vent were sometimes visible, and lava from the crater flowed in tubes as well as on the surface. Visible activity at the vent occasionally paused for various lengths of time. 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.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that daily white-and-gray plumes from Lewotolok rose as high as 1 km and drifted W, NW, NE, and E during 13-20 July. Rumbling was heard daily. Incandescent material was ejected as far as 1 km from the summit vent in various directions during 16-18 July. 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 and the lava dome in the summit crater both remained active during 9-15 July. The SW rim lava-dome volume was an estimated 1.83 million cubic meters and continued to shed material down the flank. One pyroclastic flow traveled 1.1 km down the SW flank and as far as 1.5 km SE. Avalanches traveled a maximum of 1.5 km SE (58 times), 2 km SW (98 times), 1 km W (one time), and 700 m NW (three times). The volume of the summit lava dome was 2.796 million cubic meters. 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.

Nevado del Ruiz – Colombia : On 21 July Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that seismicity at Nevado del Ruiz was generally characterized by higher number of earthquakes that had larger magnitudes than the previous week. Gas-and-steam emissions were sometimes visible in webcam images rising as high as 1.1 km above the summit and drifting WNW and WSW; these emissions sometimes contained ash. Episodes of drumbeat seismicity were recorded during 13-14 and 17 July, indicating ascent or growth of a lava dome in Arenas Crater. The Alert Level remained at 3 (Yellow; the second lowest level on a four-colour scale).

Sangay – Ecuador : IG reported a high level of activity at Sangay during 13-20 July. Weather clouds and rain sometimes prevented visual and webcam observations of the volcano. Daily ash plumes were identified in satellite images by the Washington VAAC, rising between 900 m to as high as 5.4 km above the volcano and drifting W, SW, SE, and NE. Ashfall was reported in Barca and Guamote (40 km WNW) on 14 July and in Guamote on 19 July. Signals indicating lahars were recorded by the seismic network during 15-16 and 18-20 July.

Santa Maria – Guatemala : INSIVUMEH reported that during 13-20 July daily explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose as high as 1 km above the summit and drifted as far as 12 km SW and W. Collapses of blocky lava from Caliente dome sent avalanches down the SW and W flanks, often reaching the base, and caused minor ashfall mostly on the volcano’s flank. Ashfall was also reported in San Marcos (8 km SW) and Loma Linda Palajunoj (6 km WSW) during 14-15 and 19-20 July. On 15 July blocks of extruded lava formed a lava flow on the W flank that was 700 m long. Block-and-ash flows descended the W and NE flanks.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that unrest continued at Semisopochnoi during 13-20 July. Periods of low-level tremor and steam plumes from Mount Cerberus were occasionally recorded. Elevated surface temperatures at the N cone of Mount Cerberus were identified in satellite images during 13-14 July and robust steam-and-gas emissions were seen in webcam images. A plume with low amounts of sulfur dioxide drifting about 200 km N was identified in satellite data on 17 July. Sulfur dioxide emissions were also detected the next day. 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 9-16 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 9-16 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : Video taken on 13 July and posted on social media showed new vents on the upper W flank of Sinabung that were producing steam-and-ash emissions. PVMBG reported that white-and-gray plumes rose 100-300 m from the summit and drifted E and SE. During 14-18 June white plumes rose as high as 300 m. An eruptive event that began around 1850 on 19 July and lasted about 11 minutes produced an ash plume that rose 1 km and drifted ESE. 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.

Whakaari/White Island-North Island (New Zealand) : GeoNet reported continuing unrest at Whakaari/White Island. During overflights of the island on 15 and 20 July scientists observed minor steam-and-gas activity around the 2019 Primary Crater lava domes and noted that the Main Crater area continues to fill with water. Other fumarolic vents remained active and unchanged. Overall, seismicity was at low levels during the previous few months, punctuated by a few notable events; a short-lived tremor episode was recorded on 2 June, discrete acoustic signals recorded during 18-20 June were associated with geysering in a new vent N of 2019 Crater, and a 15-minute low-frequency volcanic earthquake occurred on 30 June. Nighttime incandescence has persisted in webcam views since the 30 June earthquake. Thermal infrared measurements taken on 15 July confirmed that temperatures at dome vents had notably increased, from around 110 degrees Celsius measured in late May-early June to 498-654 degrees. Gas emissions had not notably changed over the previous few months as confirmed during the 20 July overflight. The Volcanic Alert Level remained at 1 and the Aviation colour Code remained at Green.

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