Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 18 November 2020 – 24 November 2020

Merapi – Central Java (Indonesia) : BPPTKG reported that during 13-23 November sometimes dense white emissions from Merapi rose as high as 200 m above the summit. Avalanches of material traveled down the flanks, as far as 2 km in the Lamat drainage (W flank) at 0615 on 14 November. A comparison of photos taken on 11 and 19 November showed morphology changes in the summit area from a collapse of part of the 2018 dome and rockfalls from parts of the crater rim. Seismicity was higher than the previous week. A notable rockfall from the inner N crater rim was recorded by the webcam at 0650 on 22 November. Electronic Distance Measurement (EDM) data continued to measure a distance shortening between points in the NW at a deformation rate of 9 cm per day during 13-19 November, though on 23 November the rate was 11 cm per day. The Alert Level remained at 3 (on a scale of 1-4).

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) and Instituto Geológico Minero y Metalúrgico (INGEMMET) reported that seismicity at Sabancaya had increased on 11 November. During the following week, the number and magnitude of explosions increased, and crater incandescence was visible in satellite and webcam data. The increased activity likely signified lava effusion, and a new lava dome in the NE part of the summit crater was confirmed in satellite images on 16 November. The dome, named Iskay, was 110 x 130 m in dimension and about 12,000 square meters in area. An IGP scientist noted that the dome was 78% smaller than the dome that had formed at the end of 2019. A daily average of 49 explosions was recorded during 16-22 November. Gas-and-ash plumes rose as high as 3.5 km above the summit and drifted in multiple directions; ashfall was reported in the Huanca district on 22 November. Thirteen thermal anomalies over the crater were 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.

Whakaari/White Island – North Island (New Zealand) : The Wellington VAAC reported that during 20-24 November steam emissions from Whakaari/White Island contained minor amounts of ash. The plumes rose as high as 1.2 km (4,000 ft) a.s.l. and drifted in multiple directions, based on webcam and satellite images and information from GeoNet.

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