STATISTICAL VARIATIONS IN ARCTIC SEA ICE RIDGING AND DEFORMATION RATES
Past studies of statistics of pressure ridges have supplied useful information on the nature of pressure ridge height and spacing distributions as well as information on geographical and temporal variations in ridging. These statistics should be of some aid in the construction of Arctic offshore structures in icebreaking and shipping operations. By coupling these height and spacing statistics with information on ridge lengths, the amount of detouring necessary to avoid ridges may be estimated. Closely associated with ridging are drift and deformation studies. Two aspects of these studies applicable to this conference are (1) the prediction of the rate of opening and closing of the pack ice, and (2) estimation of typical geophysical stresses in the ice pack. Theoretical and experimental work at CRREL indicates that certain approximate rules may be invoked to estimate the divergence rate far from coastal boundaries, namely that in winter, the pack ice should diverge in reasonably well localized high pressure systems, whereas in summer the ice typically diverges in low pressure systems. As regards estimates of geophysical stresses, estimates from a variety of sources suggest that maximum stresses integrated through the pack ice thickness are of the order of 10 to 4th power to 15 5th power N/m. The upper limit, 15 to 5th power N/m, is approximately equal to the force required to crush 0.25-meter-thick sea ice.
- Presented at the Ice Tech Symposium, Montreal, Canada, April 9-11, 1975.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ USA 07306-2907
- Hibler III, W D
- Publication Date: 1975-4
- Features: References;
- Pagination: 9 p.
- TRT Terms: Ice; Ice phenomena; Motion; Offshore structures; Pack ice
- Old TRIS Terms: Ice deformation; Ice movement; Ice ridges
- Subject Areas: Bridges and other structures; Marine Transportation;
- Accession Number: 00095329
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Files: TRIS
- Created Date: May 29 1975 12:00AM