Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 11 November 2020 – 17 November 2020

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 7-9 and 12 November. An explosion on 8 November produced an ash plume that rose to 8 km (26,200 ft) a.s.l. and drifted 230 km NE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that Strombolian activity at Klyuchevskoy continued during 6-13 November and lava advanced down the Apakhonchich drainage on the SE flank. Gas-and-steam emissions contained some ash and during 7-9 November drifted 85 km E. A large bright thermal anomaly was identified daily in satellite images. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale) on 8 October.

Merapi – Central Java (Indonesia) : BPPTKG reported that during 6-12 November sometimes dense white emissions from Merapi rose as high as 250 m above the summit. The report noted that the lava-dome volume was an estimated 200,000 cubic meters based on analyses of drone images captured on 3 November. Avalanches of material traveled 3 km down the WSW flank in the Putih/Sat drainage at 1450 on 8 November. Photos from 11 November showed no changed to the morphology of the lava dome in the summit crater. Electronic Distance Measurement (EDM) data continued to detect shortening between points in the NW at a deformation rate of 10 cm per day. Seismicity was higher than the previous week. On 13 November BPPTKG noted that avalanches had been traveling 1-3 km down the N and NW flanks, indicating summit instability. Authorities recommended no activities within 5 km of the summit. BNPB reported that as of 15 November more than 1,800 residents from the surrounding districts of Boyolali, Magelang, Klaten, and Sleman had been relocated to shelters. Livestock was also being relocated, particularly from three villages within 7 km of the summit. PVMBG noted that less than a dozen rock avalanches were heard at observations posts during 15-17 November. The Alert Level remained at 3 (on a scale of 1-4).

Whakaari/White Island – North Island (New Zealand) : Following a period of severe weather, on 11 November GeoNet reported some mainland observations of darker plumes and deposits on webcams; scientists conducted an overflight of Whakaari/White Island on 12 November to investigate. Aerial observations confirmed the presence of ash in the emissions, originating from the main steam vent at the back of the crater lake. An initial analysis indicated that the ash was from loose material around the vent being entrained into the gas-and-steam plumes. The Volcanic Alert Level was raised to 2 and the Aviation Color Code remained at Yellow reflecting greater unrest at the surface. There was no notable change in the location and size of active vents, though rainwater had created a small shallow lake on the floor of the 1978/90 Crater. A small earthquake sequence and several episodes of slightly increased volcanic tremor were recorded the previous week; the seismic data and observations were unusual for the volcano and may be coincident with the ash in the plume. Gas output was higher than previous recent observations; carbon dioxide flux was 2,390 tonnes/day and sulfur dioxide flux was 618 tonnes/day. The Wellington VAAC noted that the gas, steam, and ash plumes rose to1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E and SE during 12-14 November, based on satellite data, reports from pilots, and GeoNet. Small amounts of ash continued to be present in emissions seen during an overflight on 16 November. Laboratory data showed that the particulates were hydrothermal minerals and old volcanic material, with no fresh magmatic ash signatures. Carbon dioxide flux was 1,937 tonnes/day and sulfur dioxide flux was 710 tonnes/day, overall slightly lower than the previous measurement but still above background levels. Seismicity remained similar to the previous week, characterized by a sequence of small earthquakes, a larger than normal volcanic earthquake located close to the volcano, and ongoing low-level volcanic tremor. Re-suspended ash to 460 m (1,500 ft) a.s.l. that drifted E and NE was reported by the VAAC during 16-17 November.

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