Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 13 January 2021 – 19 January 2021

Aira – Kyushu (Japan) : JMA reported that during 11-18 January incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was often visible nightly. The sulfur dioxide emission rate remained high, reaching 2,100 tons per day on 13 January. Five explosions and three eruptive events were recorded, producing eruption plumes that rose 1.3-2 km above the crater rim and ejecting bombs 500-900 m away from the crater. 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 13-14 January ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted E and WSW. 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 7-10 and 13-14 January; ash plumes rose up to 4.5 km (14,800 ft) a.s.l. and drifted E. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna – Sicily (Italy) : INGV reported that during 11-17 January activity at Etna was characterized by intra-crater Strombolian activity at Northeast Crater (NEC), occasional ash emissions from the Voragine (VOR) and Bocca Nuova (BN) craters, and Strombolian activity, lava effusion, and ash emissions at the Southeast Crater (SEC). In general, the activity was similar to the pervious week, though activity at SEC on 18 January was notable. Lava effusion began around 0700 on 17 January but was confined to the SEC summit cone. At around 0740 the lava breached the crater and lava flowed down to the base of the cone. The effusion rate increased by 0819 and an ash emission was possibly visible; the lava flow lengthened and had reached an elevation of 3,000 m by 1000. Weather clouds moved in and prevented visual observations until 1830 on 18 January when the lava flow was visible again; it was no longer being fed and was cooling. Volcanic tremor amplitude increased and Strombolian activity intensified at 2000. A new lava flow emerged at 2015 and traveled towards the Valle del Bove, reaching an elevation of 2,900 m. Low lava fountains were visible at 2130 and an ash plume drifted ESE, causing ashfall on the downwind flank. Lava flows descended the SE, E, and NE flanks of the SEC. Explosive activity significantly decreased at 2200. Two distinct lava flows were visible, with one heading N and the other moving towards the Valle del Bove. Tremor and infrasound signals decreased to pre-episode levels by 2230. The the lava flows were stable and cooling on 19 January.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 8-15 January. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that Strombolian and sometimes Vulcanian activity at Klyuchevskoy continued during 8-15 January and lava advanced down the Kozyrevsky drainage on the S flank. A large bright thermal anomaly was identified daily in satellite images. Steam-and-gas plumes with some ash rose to 6 km (19,700 ft) a.s.l. and drifted 90 km in multiple directions. The Aviation colour Code remined at Orange (the second highest level on a four-colour scale).

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that a Strombolian eruption at Lewotolo continued during 13-19 January. Gray-and-white ash plumes rose 200-700 m above the summit daily and rumbling sounds were reported. Strombolian explosions ejected material 100-500 m above the summit, and incandescent material was ejected as far as 1.5 km SE from the crater. 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.

Ruapehu – North Island (New Zealand) : GeoNet reported that volcanic tremor at Ruapehu declined to low levels on 29 December 2020, and remained low; volcanic gas emissions returned to background levels by the next day. Water chemistry had only slightly changed compared to data collected a few weeks prior. Although the temperature of the crater lake water remained high (40 degrees Celsius), the period of heightened unrest was over; the Volcanic Alert Level was lowered to 1 and the Aviation colour Code was lowered to Green on 11 January.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 29 explosions at Sabancaya during 11-17 January. Gas-and-ash plumes rose as high as 3 km above the summit and drifted in multiple directions. One thermal anomaly over the crater was identified in satellite data. Minor inflation continued to be detected in areas N of Hualca Hualca (4 km N) and on the SE flank. 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 during 1-15 January incandescent avalanches of material from the Jonggring Seleko Crater at Semeru sometimes traveled 500-1,000 m down the Kobokan drainage on the SE flank. Incandescent material was ejected 10-30 m above the summit and white-and-gray plumes rose 200-300 m and drifted N. Weather conditions often prevented visual observations. A pyroclastic flow was detected at 1451 on 1 January, though weather clouds prevented visual confirmation. At 1724 on 16 January incandescent avalanches traveled as far as 1 km down the Kobokan drainage and a pyroclastic flow traveled about 4-4.5 km down the same drainage. A large ash cloud rose along the length of the pyroclastic flow to 2 km above the summit and drifted NE and N. Ashfall was reported in areas to the N. During 18-19 January dense gray-white plumes rose 300-500 m above the summit and drifted N. Rumbling was heard and incandescent material was ejected 30 m high. 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.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 8-15 January. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Shishaldin – Fox Islands (USA) : AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 15 January AVO changed both the Aviation colour Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with local webcams, satellite data, and remote infrasound, seismic, and lightning networks.

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 13-19 January, though weather conditions often prevented visual conformation. White-and-gray ash plumes rose as high as 500 m above the summit during 14-15 January, and avalanches of material traveled 700-1,000 m down the SE flank. Dense white-and-gray ash plumes rose 500 m during 17-18 January. 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.

Veniaminof – United States : AVO reported that seismic data for Veniaminof had not been received since 8 December 2020 due to a problem with the satellite link at Port Heiden. Both the Aviation colour Code and the Volcano Alert Level were changed to Unassigned on 15 January, reflecting the lack of available seismic data to detect unrest.

Yasur – Vanuatu : Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that an ash-and-gas emission rose above Yasur’s crater rim at 1734 on 18 January. The Alert Level remained at 2 (on a scale of 0-4). VMGD reminded residents and tourists that hazardous areas were near and around the volcanic crater, and that volcanic ash and gas could reach areas impacted by trade winds.

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