It is shown that the cardinal revision, attempted in 1988 and 1998, of the G.S. Gorshkov hypothesis as to the explosive origin of the debris avalanche (“directional explosion agglomerate”) caused by the 30 March, 1956 culminating phase of the catastrophic eruption on Bezymiannyi Volcano, Kamchatka does not rest on a safe foundation. The hypothesis of a different (avalanche-landslide) origin, similar to the May 18, 1980 Mount St. Helens, U.S. event, must be rejected owing to an absence of necessary evidence. New arguments are adduced to support the Gorshkov hypothesis, corroborating that the main factor that caused the debris avalanche was a giant directional explosion.

Volcanic ash is a useful tool for investigation of the history of volcanic eruptions as it can be found far from
eruptive centers, and is preserved for a long time after initial deposition and has a constant mineral composition.
Imperfection of most methodical investigations of volcanic ashes is their texture sensibility. This factor make difficult
to identify volcanic ashes from the same volcano. Some magnetic properties, saturation magnetization, saturation magnetization field, and Curie Point (Tc) of magnetic minerals, however, are not sensitive to texture, but they are sensitive to magnetic-mineral composition. A more sensitive method for determining the Tc- point is the analysis of the temperature dependence of magnetic susceptibility or of inductive magnetization. The presence of peaks on the curve near the Tc-point for the monomineralic fractions (Hopkinson’s peak) helps to more carefully define individual Tc on the curve for natural mixtures of the different magnetic minerals.