The 2020 Activity of Kamchatkan Volcanoes and Danger to Aviation

<p>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.</p><p>There are 30 active volcanoes in the Kamchatka, and several of them are continuously active. Scientists of KVERT monitor Kamchatkan volcanoes since 1993. In 2020, four of these volcanoes (Sheveluch, Klyuchevskoy, Bezymianny, and Karymsky) had strong and moderate explosive eruptions.</p><p>The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and it is continuing at present. In 2020, strong explosions sent ash up to 7-10 km a.s.l. on 08 April, and 22 and 29 December. Ash from explosions rose up to 5-6 km a.s.l. on 13 June, and 24 December. Ash plumes extended more 625 km mainly to the south-east of the volcano. A form of resuspended ash was observed on 20 April, 28 June, 24 August, and 07-10 October: ash plumes extended for 310 km to the northeast and southeast of the volcano. Activity of Sheveluch was dangerous to international and local aviation.</p><p>Two moderate explosive-effusive eruptions of Klyuchevskoy volcano occurred in 2020: first from 01 November 2019 till 03 July 2020, and second from 30 September, it is continuing in 2021. Explosions sent ash up to 7 km a.s.l., gas-steam plumes containing some amount of ash extended for 465 km to the different directions of the volcano. The lava flows moved along Apakhonchichsky and Kozyrevsky chutes. Activity of the volcano was dangerous to local aviation.</p><p>The strong explosive eruption of Bezymianny volcano occurred on 21 October: explosions sent ash up to 11 km a.s.l., the large ash cloud was located over Klyuchevskoy group of volcanoes long time and later drifted up to1200 km to the southeast of the volcano. Activity of the volcano was dangerous to international and local aviation.</p><p>Eruptive activity of Karymsky volcano was uneven in 2020: ash explosions were observed from one (June) to seven (October) days a month, for five months the volcano was quiet. Explosions rose ash up to 8 km a.s.l. (08 November), ash plumes and clouds drifted for 380 km to the different directions of the volcano. The eruptive volcanic activity was observed in April, May, June, July, October, November, and December. Activity of Karymsky was dangerous to international and local aviation.</p>

Karymsky volcano eruptive plume properties based on MISR multi-angle imagery and the volcanological implications

Space-based operational instruments are in unique positions to monitor volcanic activity globally, especially in remote locations or where suborbital observing conditions are hazardous. The Multi-angle Imaging SpectroRadiometer (MISR) provides hyper-stereo imagery, from which the altitude and microphysical properties of suspended atmospheric aerosols can be derived. These capabilities are applied to plumes emitted at Karymsky volcano from 2000 to 2017. Observed plumes from Karymsky were emitted predominantly to an altitude of 2–4 km, with occasional events exceeding 6 km. MISR plume observations were most common when volcanic surface manifestations, such as lava flows, were identified by satellite-based thermal anomaly detection. The analyzed plumes predominantly contained large (1.28 µm effective radius), strongly absorbing particles indicative of ash-rich eruptions. Differences between the retrievals for Karymsky volcano's ash-rich plumes and the sulfur-rich plumes emitted during the 2014–2015 eruption of Holuhraun (Iceland) highlight the ability of MISR to distinguish particle types from such events. Observed plumes ranged from 30 to 220 km in length and were imaged at a spatial resolution of 1.1 km. Retrieved particle properties display evidence of downwind particle fallout, particle aggregation and chemical evolution. In addition, changes in plume properties retrieved from the remote-sensing observations over time are interpreted in terms of shifts in eruption dynamics within the volcano itself, corroborated to the extent possible with suborbital data. Plumes emitted at Karymsky prior to 2010 display mixed emissions of ash and sulfate particles. After 2010, all plumes contain consistent particle components, indicative of entering an ash-dominated regime. Post-2010 event timing, relative to eruption phase, was found to influence the optical properties of observed plume particles, with light absorption varying in a consistent sequence as each respective eruption phase progressed.

Leaching of trace elements from the rocks under action of organic acids

The experiments on studying leaching of trace elements (Li, Rb, Cs, Sr, Ba, V, Mn, Fe, Co, Ni, Cu, Tl, Y, La, Ce, Th, U) from unaltered ash of the Karymsky volcano (Kamchatka) under its interaction with 0.01 M solutions of oxalic, salicylic, tartaric, citric, and acetic acids at the different solid/liquid phases mass ratio were lead. Based on the obtained data it is drawn a conclusion that mobilization of trace elements occurs mainly as a result of demolition of crystal structure of rock-forming minerals, as well as (in case of oxalic acids) at reduction of Fe(III) and Mn(IV) oxyhydroxides to soluble Fe(II) and Mn(II) compounds. Organic complexes formation increases of the metals stability in solution and provides a possibility of achievement of much higher values of the dissolved forms concentration than for the lack of organic ligands.

Tracking microphysical variations in emissions from Karymsky volcano using MISR multi-angle imagery, and implications for volcano geologic interpretation

Space-based, operational instruments are in unique positions to monitor volcanic activity globally, especially in remote locations or where suborbital observing conditions are hazardous. The Multi-angle Imaging SpectroRadiometer (MISR) provides hyper-stereo imagery, from which the altitude and microphysical properties of suspended atmospheric aerosols can be derived. These capabilities are applied to plumes emitted at Karymsky volcano from 2000 to 2017. Plumes from Karymsky were predominantly emitted to an altitude of 2–4 km, with occasional events exceeding 6 km. MISR plume observations were most common when volcanic surface manifestations were high, such as lava flows identified by satellite-based thermal anomaly detection. The plumes contained large, strongly absorbing particles indicative of ash-rich eruptions. Differences between the retrievals for Karymsky volcano's ash-rich plumes and the sulfur-rich plumes from the 2014–2015 eruption of Bárðarbunga (Iceland) highlight the ability of MISR to distinguish particle types from such events. Plumes emitted at Karymsky prior to 2010 contain the sulfate proxy. After 2011, plumes contain similar particle components, but with varying fractions of absorption linked to timing within respective eruption phases. From the 1.1 km spatial-resolution retrievals within 30–220 km plumes, particle fallout, physical aggregation, and chemical evolution are indicated by the particle property variations observed downwind. In addition, changes in plume properties retrieved from the remote-sensing observations over time are interpreted in terms of activity cycles within the volcano itself, corroborated to the extent possible with suborbital data.