Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 3 February 2021 – 9 February 2021

Etna – Sicily (Italy) : INGV reported that Strombolian activity from all four of Etna’s summit craters, the Southeast Crater (SEC), the Northeast Crater (NEC), Bocca Nuova (BN), and Voragine (VOR), was visible during 1-7 February; the last time that had occurred was during 1998-1999. The strongest and almost continuous Strombolian explosions at SEC originated from two vents in the E part of the top of the cone. Tephra accumulated near the top of the cone and rolled down the flanks. Minor ash emissions rapidly dispersed. Less-intense Strombolian activity occurred at the S vent. Intra-crater Strombolian activity at NEC sometimes produced nighttime crater incandescence. Strombolian activity at BN sometimes ejected coarse material beyond the crater rim, and rare ash emissions that had diffuse ash content. On 5 February scientists observed explosions from three vents at the bottom of the crater that had formed cinder cones. Nearby was another cone that occasionally produced dense emissions that rapidly dispersed. Strombolian activity at VOR ejected material that sometimes rose above the crater rim and generated diffuse ash emissions. On 5 February lava flowed into BN, overlapping flows from the previous week.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome continued to grow just below Merapi’s SW rim during 29 January-4 February. One pyroclastic flow descended the SW flank as far as 600 m. The 2021 lava dome volume was an estimated 117,400 cubic meters on 4 February, with a growth rate of about 12,600 cubic meters per day. A comparison of photos taken on 21 January and 4 February showed that the morphological changes in the summit area were attributed to the growth of the 2021 lava dome as well as from a new dome slowly growing in the summit crater. Electronic Distance Measurement (EDM) data showed no notable deformation. Seismic activity was lower than the previous week. BNPB noted that a total of 537 people remained evacuated (190 people from Sleman Regency and 347 from Klaten) as of 3 February. 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 ash plumes rose as high as 1 km above Raung’s summit and drifted S and E during 3-6 February. Ash plumes rose 1.2-2 km above the summit during 7-9 February and drifted SE and E. Incandescence from the crater was often seen reflected in the emissions, and rumbling and roaring was sometimes heard. 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.

Semisopochnoi – United States : AVO reported that a 6 February satellite image of Semisopochnoi showed small ash deposits extending in a narrow strip less than 3 km N of North Cerberus Crater. The deposits were likely the result of a small explosions that occurred during the previous week. Steam emission obscured view of the summit crater. The Aviation colour Code and the Volcano Alert Level were raised to Yellow/Advisory. A second ash deposit, similar to the first, was visible in a satellite image on 7 February. This deposit extended at least 3 km NE of North Cerberus Crater. Weather clouds obscured views of the S side of the volcano. The report noted that the ash plumes associated with the deposits had not been observed; they likely rose less than 3 km (10,000 ft) a.s.l. and were short lived. The Aviation colour Code and the Volcano Alert Level were raised to Orange/Watch.

Sarychev Peak – Matua Island (Russia) : KVERT reported that the eruption at Sarychev Peak continued during 29 January-5 February, characterized by lava effusion from the carter onto the N flank. A thermal anomaly was identified in satellite images on 29 January and 1 February; weather clouds prevented observations on the other days. The Aviation colour Code remained at Yellow (the second lowest level on a four-colour scale).

from WordPress https://ift.tt/3qbmrTD