Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 27 January 2021 – 2 February 2021

Karangetang – Siau Island (Indonesia) : The Darwin VAAC reported that on 29 January a pilot observed an eruption plume rising from Karangetang to 2.4 km (8,000 ft) a.s.l. and drifted SW. The next day an ash plume identified in satellite images rose to 3 km (10,000 ft) a.s.l. and drifted SW. The Alert Level remained at 2 (on a scale of 1-4).

Merapi – Central Java (Indonesia) : BPPTKG reported that the “2021 lava dome” continued to effuse just below Merapi’s SW rim during 22-28 January, producing a total of 230 incandescent lava avalanches that traveled as far as 1.5 km down the Krasak and Boyong river drainages on the SW flank. Pyroclastic flows were recorded 71 times and descended the Boyong drainage as far as 3.5 km. A comparison of photos taken on 21 and 26 January showed that the morphological changes in the summit area were attributed to the emergence of lava domes. The 2021 dome volume was an estimated 157,000 cubic meters on 25 January, but avalanches and pyroclastic flows during 26-27 January reduced the volume to 62,000 cubic meters based on 28 January estimates. Deformation continued, though at a lower rate; Electronic Distance Measurement (EDM) data showed a distance shortening between points in the NW at a rate of 0.4 cm per day. There were 36 pyroclastic flows recorded during 0000-1400 on 27 January; the longest pyroclastic flow traveled 3 km down the Krasak and Boyong drainages at 1253. The corresponding ash plume rose into low weather clouds that obscured the summit. At 1335 pyroclastic flows traveled 1.5 km SW. Sirens were triggered in Ngrangkah, Umbulharjo, Cangkringan, and Sleman (along the Boyong river drainage), alerting about 150 residents to temporarily evacuate. Ashfall was reported in several villages in the Tamansari and Musuk districts, Boyolali Regency, Boyolali City, and several locations in Klaten. 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.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-to-brown ash plumes rose 400-700 m above Raung’s summit and drifted SE, E, and NE during 26 January-2 February. Incandescence from the crater was often seen reflected in the emissions and rumbling was sometimes heard. At 2354 on 2 February an ash plume rose 1 km and drifted E. 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.

Sarychev Peak – Matua Island (Russia) : KVERT reported that the eruption at Sarychev Peak continued during 22-29 January, characterized by lava effusion from the carter onto the N flank. A daily thermal anomaly was identified in satellite images. The Aviation colour Code remained at Yellow (the second lowest level on a four-colour scale).

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater was an estimated 428 m long, 217 m wide, 80 m high, and had a volume of 4.45 million cubic meters by 27 January. The dome continued to grow during 27 January-2 February. During a field visit on 1 February scientists observed that gas-and-steam continued to rise from the top of the dome as well as along the contact of the old and new domes. Gas-and-steam plumes were often visible from Belmont Observatory. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Tinakula – Solomon Islands : Thermal anomalies over Tinakula’s summit and on the WNW flank were periodically visible in satellite images during 17 December 2020-21 January 2021. Weather clouds often obscured views.