The 2021 Activity of Kamchatkan Volcanoes and Danger to Aviation

Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines.

There are 30 active volcanoes in the Kamchatka; scientists of KVERT monitor these volcanoes since 1993. Description of volcanic eruptions is based on video monitoring and various satellite data from the information system "Remote monitoring of the activity of volcanoes of the Kamchatka and the Kuriles" (VolSatView, http://kamchatka.volcanoes.smislab.ru). In 2021, three volcanoes (Sheveluch, Klyuchevskoy, and Karymsky) had eruptions.

The eruptive activity of Sheveluch (growth of the lava dome) is continuing since 1980. In 2021, explosions sent ash up to 7.5 km a.s.l. mainly in August and December; ash plumes were extending more 380 km to the different directions of the volcano. A new plastic lava block Dolphin-2 squeezed at the dome from February till July 2021. Resuspended ash was observed on 02-03 April, 06-07 July, 13-14 and 22 August, and 06-07 and 21 October: ash plumes were extending for 400 km to the east and southeast of the volcano. Satellite data by KVERT showed a thermal anomaly over the volcano all year. Activity of the volcano was dangerous to local aviation.

The terminal explosive-effusive eruptions of Klyuchevskoy volcano took place from 30 September, 2020 to 08 February, 2021. Explosions sent ash up to 8 km a.s.l., gas-steam plumes containing some amount of ash were extending for 500 km to the different directions of the volcano. The lava flows moved along Apakhonchichsky and Kozyrevsky chutes. Satellite data by KVERT showed a thermal anomaly over the volcano all year. The lateral break on the northwestern slope of Klyuchevskoy at an altitude of 2.8 km a.s.l. lasted from 17 February to 20 March, 2021: lava effused from two cracks, a cinder cone 60 m high was formed. By February 23, lava flows 1.2 km long reached the Erman glacier, mud flows passed about 30 km. Activity of the volcano was dangerous to international and local aviation.

Eruptive activity of Karymsky volcano was uneven in 2021. According to satellite data, the strong ash explosions were observed: on 04 April (8.5 km a.s.l.), 10 September (7 km a.s.l.), 03 November (11 km a.s.l.), and 06, 13, and 18 November (8 km a.s.l.); in the other months explosions sent ash up to 6 km a.s.l.; ash plumes and clouds drifted for 2700 km to the different directions from the volcano. The thermal anomaly over the volcano was recorded on satellite images from time to time. Activity of the volcano was dangerous to international and local aviation.