Accession Number:

ADA200172

Title:

Profile Properties of Undeformed First-Year Sea Ice

Descriptive Note:

Corporate Author:

COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

Personal Author(s):

Report Date:

1988-09-01

Pagination or Media Count:

64.0

Abstract:

In many sea ice engineering problems the ice sheet is assumed to be a homogeneous plate whose mechanical properties are estimated from the bulk salinity and average temperature of the ice sheet. Typically no regard has been given to the vertical variation of ice properties in the ice sheet or to time of ice formation. This paper reviews some of the mechanical properties of sea ice, including ice tensile, flexural and shear strengths, as well as the ice modulus. Equations for these properties are given as functions of the ice brine volume, which can be determined from ice salinity and temperature. A numerical, finite difference model is developed to predict salinity and temperature profiles of a growing ice sheet. In this model ice temperatures are calculated by performing an energy balance of the heat fluxes at the ice surface. The conductive heat flux obtained from the energy balance is then used to calculate the rate of ice growth and ice thickness by applying the Stefan ice growth equation. Ice salinities are determined by considering the amount of initial salt entrapment at the icewater interface and the subsequent brine drainage due to brine expulsion and gravity drainage. Ice salinity and temperature profiles are then generated using climatological data for the Central Arctic Basin. The profiles appear to be realistic and agree reasonably well with field data. Mechanical property data is developed to provide mechanical property profiles for first - year sea ice of different thicknesses, grown at different times of the winter. The predicted profiles give composite plate properties that are significantly different from bulk properties obtained by assuming homogeneous plates.

Subject Categories:

  • Snow, Ice and Permafrost

Distribution Statement:

APPROVED FOR PUBLIC RELEASE