1. ERDC Knowledge Core
2. Pre - Engineer Research and Development Center (ERDC)
3. Snow, Ice and Permafrost Research Establishment (SIPRE) - (1947 - 1961)
4. Publication
5. Research Report

Title:	Visco-elastic properties of snow and ice in the Greenland ice cap
Authors:	Nakaya, Ukichirō, 1900-1962
Keywords:	Ice Glacier ice Elasticity Plasticity Viscoelasticity Ice tunnels Snow tunnels Core samplers Snow density Greenland Ice sheet Ice cap Glaciers
Publisher:	U.S. Army Snow, Ice, and Permafrost Research Establishment. Engineer Research and Development Center (U.S.)
Description:	Research Report Summary: The results of studies in the summer of 1957 on ice samples taken from the ice tunnel at TUTO, core samples obtained by drilling in the ice cap at Site 2, and snow samples, using the transverse vibration method and a new portable meter, are reported. Young's modulus was determined from the resonance frequency of flexural vibrations of samples cut in the form of rectangular bars; the loss factor was measured from damping; and the coefficient of viscosity calculated using the Maxwell model. The modulus of elasticity of samples of a density from 0.917 - 0.90 g/cm^3 (tunnel ice) decreased sharply with slight deviations of the density from that of pure ice. At densities from 0.90 - 0.50 g/cm^3 (deep-pit and drill-core samples) the relation between the modulus of elasticity and density was linear, while in the density range from 0.50-0.25 g/cm^3 (surface snow) the modulus of elasticity decreased exponentially. The viscosity-density relation of the samples was similar to that of elasticity vs density. Young's modulus increased slightly with decreasing temperature, while viscosity increased exponentially. The activation energy was calculated as 18.7 kcal/mol for old ice-cap ice, 13.9 kcal/mol for tunnel ice with elongated bubbles, and 13.5 kcal/mol for super-imposed ice.
Rights:	Approved for public release; distribution is unlimited.
URI:	http://hdl.handle.net/11681/2726
Appears in Collections:	Research Report