Permeability of winter and spring first-year ice in the Antarctic marginal ice zone

• Main Author: Lin, Xuefeng
• Other Authors: Skatulla, Sebastian
• Format: Master Thesis
• Language: English
• Published: Department of Civil Engineering 2022
• Subjects: Engineering; Antarctic; Southern Ocean; The Antarctic; Pancake; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/11427/37472

This study was part of the 2019 Southern oCean seAsonal Experiment (SCALE) Winter and Spring Cruise of the South African icebreaker SA Agulhas II. First-year spring and winter sea ice were sampled from the Antarctic marginal ice zone. Consolidated pack ice was collected during both cruises, while pancake ice floes and brash ice floes were collected during Winter and Spring Cruise, respectively. The ice cores analyses of temperature, salinity, and texture were subsequently performed during the Spring and Winter Cruise, and an additional falling head permeability test was conducted during the Spring Cruise. The brine volume is determined empirically from sea ice temperature and bulk salinity. The ice permeability is then calculated from the porosity-permeability relation. The mean permeability of spring pack ice is 2.6 × 10−11 ± 3.67 × 10−11 m2 , marginally higher than the winter pack ice with a mean permeability of 1.1×10−11±2.3×10−11 m2 . Comparing the permeability values of spring and winter consolidated pack ice shows a continuous increase in permeability with seasonal progressions and a rise in ice temperature. The falling head permeability test using kerosene has been made in-house by Hasham Taujoo to determine the in situ sea ice permeability during the Spring Cruise. The experimentally determined permeability values of spring consolidated pack ice were consistent with the above-stated permeability data. However, the permeability values of spring brash ice floes (1.4 × 10−11 ± 2.12 × 10−11 m2 ) determined from porositypermeability relation deviate from field observations due to the presence of large holes and cracks on the ice samples.