Comparison of the catastrophic pulsation (post-volcanic explosion-like sudden gas-dynamic outburst) of the Kolka glacier with the subvolcanic processes of formation and functioning of the volcanic pipes (diatremes)

Abstract

There are certain analogies in the manifestation mechanism of subvolcanic, volcanic and postvolcanic gas-dynamic processes of explosive or explosion-like type. According to the features of their manifestation quite reliably recorded by many researchers, the latter of them includes the explosive gas-dynamic outburst of the Kolka glacier. The most essential element of the similarity between these processes consists in their gas-dynamic character, the participation of natural gases of a high and at some stages an extremely high pressure as their main working body in their manifestation. This moment is of the greatest interest in the study of the catastrophic pulsation of the Kolka glacier, the definition of its nature, the identification of its geodynamic type. The existence of analogies between the paroxysmal explosion-like ouburst of the Kolka glacier and the processes of formation and functioning of subvolcanic volcanic pipes sheds additional light on some details of the preparation processes and manifestation of this pulsation. The diatreme-like morphostructure (a large cavity representing the mouth of the gas-producing channel in its upper part) exists in the back of the Kolka glacier bed at the intersection point of the sublatitudinal Syrkhu-Barzond and submeridional East-Dzhimarai faults. The origin of this cavity is associated with a concentrated intense breakthrough of a huge amount of high-pressure deep postvolcanic gases, their powerful effect on rocks in the breakthrough zone and the subsequent explosive gasdynamic outburst of the glacier, as well as a certain amount of material of its rock-bearing substrate from the upper part of the gas output channel, in the place of which diatreme-like cavity. The filling of this cavity occurred mainly as a result of the collapse of its walls, the inverse fall of a part of the outburst material and the receipt of subsequent collapses material, and partly, possibly, due to the introduction of material from the products of destruction of the underlying rocks with an ascending gas flow that lasted for some time after the ouburst of the glacier (until the main amount of high-pressure deep-water gases has broken through into this zone).