Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 30 December 2020 – 5 January 2021

Hawaiian Islands (USA) – HVO reported that lava effusion from a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to feed a growing lava lake during 30 December-5 January. A cone had formed over the remaining active vent, which was one of three that had opened at the beginning of the eruption. Lava sometimes spattered from vents at the top of a cone and flowed down into the lake through a crusted-over channel; during 2-5 January a dome fountain was visible near the lake’s margin, formed by upwelling of lava as in entered the lake at a partially submerged inlet. The lake deepened from 181 m on 30 December to 191 m by 4 January, and the lake volume was an estimated 26 million cubic meters by 4 January. An island of cooler, solidified lava continued to float around on the lava lake’s surface, and by 4 January the island’s surface was 1-2 m above the surface of the lava lake. Over the week the island was joined by less than a dozen other small islands of cooled and solidified material that also moved around, though they mostly remained in the eastern part of the lake. The lava lake was also becoming perched as overflows of lava onto the narrow edge formed around the lake’s margins continued to build a levee; by 3 January the lake was perched about 1 m above the margin. Sulfur dioxide emissions fluctuated between 3,000 and 6,500 tonnes/day. Seismicity remained elevated but stable.

Merapi – Central Java (Indonesia) : BPPTKG reported that during 25-31 December rock avalanches traveled as far as 1.5 km down Merapi’s NW flank in the Senowo drainage. A comparison of photos taken on 24 and 30 December showed minor morphological changes in the summit area. Seismic activity was more intense than the previous week. Electronic Distance Measurement (EDM) data continued to measure a distance shortening between points in the NW at a rate of 14 cm per day. Incandescence from the crater was visible at night on 31 December, possibly signifying the emergence of lava. At 1952 on 4 January avalanches on the SW flank were recorded by webcams and heard at the Merapi Babadan observation post, and were coincident with the appearance of another incandescent area. That same day BNPB noted that 1,115 residents remained in evacuation centers. Descending incandescent material was visible on the upper SW flank during 1847-1911 on 5 January. 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.

Soufriere St. Vincent – St. Vincent : The Seismic Research Centre at the University of the West Indies (UWI-SRC) and National Emergency Management Organisation (NEMO) of St. Vincent and the Grenadines reported that during an overflight at 1600 on 31 December scientists confirmed that the new lava dome on the WSW edge of Soufrière St. Vincent’s 1979 lava dome continued to grow. Steam from the dome was visible from Belmont Observatory through 4 January. The Alert Level remained at Orange (the second highest level on a four-color scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that two explosions, on 29 and 30 December, were recorded at Suwanosejima’s Ontake Crater. Crater incandescence was visible at night during 1-4 January, and eruption plumes rose as high as 1.2 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

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