Академическое издательство «Гео»

Glacier, acoustic emission, deformation change of structure, rheology

KRIOSFERA ZEMLI, 2010, Vol. XIV, № 4, p. 42-55

Acoustic characteristics as an indicator
of the specifics of ice movement in glaciers

V.P. Epifanov, A.F. Glasovskiy*

Ishlinsky Institute for Problems Mechanics, RAS, 119526, Moscow, pr. Vernadskogo, 101, build. 1, Russia, evp@ipmnet.ru
* Institute of Geography, RAS, 119017, Moscow, Staromonetnyi per., 29, Russia, icemass@yandex.ru

Results of studies of the wave phenomena occurring during the deformation of natural ice and reflected in its acoustic characteristics are presented. The theoretical and laboratory studies allow us to compile the inventory of acoustic emission signals aimed to decode acoustic events in the active glacier sites. The studies are based on the data of measuring of rheological characteristics of natural ice, its acoustic characteristics in the ultrasonic range of frequencies at the stretching, compression and shear, as well as the quantity and spectral structure of acoustic emission signals. The radiation of elastic waves resulted from deformational reorganization of ice structure, and study of the phenomenology of their source promotes understanding of the fundamental problem of glaciology related to glacier ice movement. First of all, it is understanding of characteristic scales of movement, components of this movement, with what and in which way its components are interrelated (temperature, friction, infringement of continuity etc.), i. e. understanding of the genetic nature of glacier movement. The obtained results are planned to be used in the development of the field acoustic measurement technique in conjunction with the measurements of ice surface velocity and the studies of ice morphology/structure.

Glacier, acoustic emission, deformation change of structure, rheology