FORMATION OF WATER RUNOFF IN A LAHAR DURING THE 1945 PAROXYSMAL ERUPTION OF KLYUCHEVSKOY VOLCANO
I.B. Seynova1, S.S. Chernomorets1, M.D. Dokukin2, D.A. Petrakov1, E.A. Savernyuk1, A.A. Lukashov1, E.A. Belousova1
1 Lomonosov Moscow State University, 1, Leninskie Gory, Moscow, 119991, Russia; devdorak@gmail.com
2 High-Mountain Geophysical Institute, 2, Lenina prosp., Nalchik, Kabardino-Balkaria Republic, 360030, Russia
A high-magnitude lahar was caused by ice and snow melting during the paroxysmal eruption of Klyuchevskoy volcano on January 1 of 1945. The distribution of erupted masses within the glacier-covered zone, where the lahar water phase originated, has been mapped using our own field observations, with reference to published and archive data. Review of factors and mechanisms responsible for volcano-glacier interactions and related lahar hazard, for Klyuchevskoy and other ice-clad volcanoes in the world, made basis for a phenomenological model. The model explains the formation of extremely voluminous water flows in lahars during paroxysmal eruptions for the case of Klyuchevskoy volcano. According to our rough estimates, the meltwater runoff from the lahar initiation zone during the event of 1945 reached 59 million m3, and the total volume of the lahar could vary from 237 to 355 million cubic meters.
Lahar, debris flow, slush flow, nival-glacial zone, paroxysmal eruption, tephra, pyroclastic flow, lava flow, thermodynamic processes, phreatomagmatic explosion, Klyuchevskoy volcano, Kamchatka