Field Measurements of the Material Properties of Sea Ice At Chukchi Borderland

Jeong, Seong-Yeob (Korea Ocean Research & Development Institute - Daedeok) | Cho, Seong Rak (Korea Ocean Research & Development Institute - Daedeok)

OnePetro 

ABSTRACT

A field experiment was conducted on August 11 and 12 of 2011 with the Korean icebreaking research vessel "Araon" at Chukchi Borderland to investigate the sea ice properties. In this research the field survey data including snow depth, thickness, freeboard, temperature, density, salinity and crystal structure of ice were investigated. Brine volume and flexural strength of ice were calculated by empirical formula. The average ice thickness was 1.81 m and salinity was 0.23 to 1.78‰. The sea ice density of upper layer was 0.770 g/cm3, middle layer was 0.896g/cm3, and lower layer was 0.916 g/cm3, and then the calculated average flexural strength of ice was about 360 kPa. The Apparent conductivities derived with the electro-magnetic induction instrument (EMI) were compared to drill hole measurement results. In addition, it is shown that the good relation between in-situ measurement results and estimated data from empirical relation between total thickness and apparent conductivity for the EMI.



INTRODUCTION

In the Arctic, sea ice conditions are influenced by global warming and increase of greenhouse gas. The Arctic sea ice cover is consistently diminishing, the amount of perennial ice has decreased, and the ice thickness has thinned. Arctic ice extent in December 2011 averaged 12.38 million square kilometers. This is the third lowest December ice extent in the 1979 to 2011 satellite data record (NSIDC, 2011). Especially sea ice thickness is one of the most important parameters for prediction of future climate changes and navigation via the Northern Sea Route. The field survey of Arctic sea ice by icebreaking vessel is very difficult and expensive tasks therefore many of new technologies being developed for dynamic and thermodynamic sea ice research and properties in the Europe and Asia. Arctic sea ice properties also have been considered a key indicator in the structural design criteria of icebreaking vessels and arctic offshore platforms to estimate design ice load and resistance for their safety management in the Arctic Ocean.