New Zealand Prepared by: Nancy Bertler
email: nancy.bertler at vuw.ac.nz
Three coffee-can devices were deployed at Victoria Lower Glacier. Two devices at the dome of the glacier (Site ?) in two of the drilling holes of the shallow firn cores and one near the valley-side glacier tongue (Site •) anchored in ice. The record shows that Victoria Lower Glacier is close to equilibrium.
In total, five snow profiles were sampled with 1cm resolution: Victoria Lower Glacier (Site?, 4m depth), Victoria Lower Glacier (Site •, 1m depth), Baldwin Valley Glacier (Site ?, 4.5m depth), Wilson Piedmont Glacier (Site ?, 3m depth) and Polar Plateau (Site ?, 2m depth). Measurements included: snow temperature and density, crystal size and structure, occurrence of melt-layers, and dust content per volume and mineralogy, tephra particles and diatom input. The snow samples were analysed in collaboration with Prof. Paul Mayewski and Dr. Karl Kreutz for major ion (Na, Mg, Ca, K, NH4, Cl, NO3, and SO4), MS (methane sulfonate), trace elements (Al, Fe, Cu, P, Mn, Sr, Si, and Zn), and isotopic ratios (?18O and ?D).
Four shallow ice cores have been recovered from Victoria Lower Glacier (Sites ?, 36m and •, 8m), Baldwin Valley Glacier (Site ?, 33m), and Wilson Piedmont Glacier (Site ?, 22m), and one intermediate ice core from Victoria Lower Glacier (Site ?, 180m). The shallow cores were drilled using the PICO 3” hand auger with powerhead. The intermediate ice core with the ICDS electromechanical 4” drill.
The shallow 36m deep ice core from Victoria Lower Glacier spans approximately the last 650 years, the 33m deep core from Baldwin Valley Glacier approximately the last 700 years.
To pack, clean and log the cores in the field, a ‘clean’ processing-room
was excavated. The room was covered with silver-coloured tarpolin and
a chute was used to lower the core barrel from the rig down into the
processing room. The core was extracted in the processing room and the
drilling barrels swapped over. The clean room also contained storage
compartments, with a constant temperature of well below –20°C.
The cores were cleaned, packed in layflat plastic and logged over a light table.
The cores were then flown out by helicopter to McMurdo Station, and stored in the Crary Ice Core Facility.
Measurements on the core include physical properties, density, dust and tephra content and mineralogy.
The analytical measurements on the water are made in collaboration with Prof. Paul Mayewski and Dr. Karl Kreutz. These include major ion (Na, Mg, Ca, K, NH4, Cl, NO3, and SO4), MS (methane sulfonate), trace elements (Al, Fe, Cu, P, Mn, Sr, Si, and Zn), and isotopic ratios (δ18O and δD).