| Summary: | Progress Code: completed Statement: For the moment the spread sheet contains an ice type column which only allows for a statement of granular or columnar ice for each 10 cm section. At 10 cm resolution one can have a mix of the two. Exactly how we will quantify each section with a mix if ice types is yet to be determined and as such this data set will change as the photos are analysed in greater detail. DC Electrical: In order to relate the fluid permeability to the electrical properties of sea ice, we also took measurements of the vertical component of the DC electrical conductivity tensor of sea ice. Cores extending to the bottom of an ice floe were taken and laid out holder. With the exception of sites 7 and 8 where we encountered a slush layer below the hard ice and could not core down to the ocean. The core bottom was determined at sites 7 and 8 to be the ice slush interface. Immediately upon extraction, holes that fit our thermistor probes were drilled every ten centimetres and a temperature profile was taken. Subsequently, slightly larger holes were drilled which fit our electrical probes (stainless steel nails). An AEMC Earth Resistivity Meter was then used to measure the resistance over 10 cm sections of the core (usually offset by 5 cm so that the measured temperature was in the centre of the section where electrical resistance was measured). The cores used in resistance measurements were taken very close to where the crystallographic cores were taken. In almost all cases the cores extracted for electrical measurements were also used for crystallographic analysis, so that there was an exact match of electrical properties with crystal structure. In such cases the DC electrical cores were then moved to a -20 degree C cold room for further processing immediately after measurements in the field. A thin vertical section, approximately 3mm thick, was taken from each of the cores stored for analysis. These sections were placed between a pair of cross polarized plates and photographed. Each photo was ...
|
|---|