ABOUT REASONS OF INTENSIFICATION OFROCKFALLSON GLACIER KOLKA BEFORE ITS CATASTHROPHIC DIS-CHARGE ON 20 SEPTEMBER 2002 AND SOME QUANTITA-TIVE ESTIMATIONS OF THESE FALLS VOLUMES

Abstract

Perceptions about tectonic reasons of pre-catastrophic intensification of rockfalls on glacier Kolka in July-September 2002 were refuted. As many other anomalous in nature and intensity natural phenomena took place in the region in this period – in a stage of preparation of catastrophic paroxysmal gasodynamic discharge of glacier Kolka, falls intensification was caused by long-term powerful concentrated (jet) breakthrough to the surface (in region of lower pressure) high-pressure deep postvolcanic gases, accompanied by rock failure, including outstripping cracking in surficial and subsurficial zones under pressure of expanding compressed gases in ways of their rising jet migration. Rockfalls intensification was also contributed by thermal influence of postvolcanic gases on rocks of cryolithic zone in upper part of rock massive. Despite their abnormal intensity precatastrophic falls on glacier Kolka play no significant role in the glacier discharge, and were neither not main nor secondary it’s reason. Baselessness and falseness of some quantitative estimations of rockfalls volumes are shown. Theory about giant rockfall on the glacier Kolka on 20 September 2002 is refuted. Long-term pre-catastrophic intense rockfalls on glacier Kolka is one of precursors of paroxysmal explosiontype gasodynamic discharge of glacier Kolka, results and signature of processes of its preparation. In no other respect these falls and their intensive investigation in more than past 10 years are not of scientific or practical interest.