The effect of H2SO4 on the stress exponent in ice single crystals
Published:January 01, 2000
I. Baker, Y. L. Trickett, P. M. S. Pradhan, 2000. "The effect of H2SO4 on the stress exponent in ice single crystals", Deformation of Glacial Materials, Alex J. Maltman, Bryn Hubbard, Michael J. Hambrey
Download citation file:
Sulphuric acid is a naturally occurring contaminant in ice. Recently, it was demonstrated that, during compression tests at –20°C and a strain rate of 1 × 10-5 s-1, as little as 0.1 ppm H2SO4 reduced both the peak strength and the subsequent flow stress of ice single crystals that deform primarily by basal slip. In the present work, compression tests were performed at –20°C at a variety of strain rates on both undoped ice single crystals and ice single-crystals containing 6.8 ppm sulphuric acid of various orientations again deforming primarily by basal slip. The results show that sulphuric acid dramatically decreases both the peak stress and the subsequent flow stress of ice single crystals at all strain rates. In contrast, the stress exponent was determined to be 1.89–1.97 and was unaffected by the dopant. This value is similar to values found by previous workers for undoped ice crystals.
Figures & Tables
Deformation of Glacial Materials
The flow of glacier ice can produce structures that are striking and beautiful. Associated sediments, too, can develop spectacular deformation structures, and examples are remarkbly well preserved in Quaternary deposits. Although such features have long been recognized, they are now the subject of new attention from glaciologists and glacial geologists.
This collection of papers addresses how the methods for unravelling deformation structures evolved in recent years by structural geologists can be used for glacial materials, and the opportunities offered to structural geologists by glacial materials for studying deformation in rocks.