Numerical Modeling of the Ash Cloud Movement from the Catastrophic Eruption of the Sheveluch Volcano in November 1964

This paper reconstructs, for the first time, motion dynamics of an eruptive cloud formed during catastrophic eruption Sheveluch volcano in November 1964 (Volcanic Explosivity Index 4+). became possible due to public availability atmospheric reanalysis data from ERA-40 archive European Center Medium-Range Weather Forecasts (ECMWF) and development numerical modeling volcanic ash propagation. The simulation process, which was carried out using FALL3D PUFF models, made it clarify sequence events this (destruction extrusive domes crater formation column pyroclastic flows), lasted only 1 h 12 min. During eruption, consisted two parts: main that rose up 15,000 m above sea level (a.s.l.), co-ignimbrite moving flows. ashfall Ust-Kamchatsk (Kamchatka) occurred at a higher speed, then cloud. In Nikolskoye (Bering Island, Commander Islands), fell Under turbulent diffusion, forefront slowly atmosphere reached 16,500 a.s.l. by 04:07 UTC on 12. Three days after began, stretched 3000 km over territories countries Russia, Canada, USA, Mexico, both Bering Sea Pacific Ocean. It is assumed well-known long-term decrease solar radiation intensity northern latitudes 1963–1966, established according world remote sensing data, associated with spread aerosol clouds not Agung volcano, but those eruption.