Abstract:
To understand the drivers and consequences of climate change on timescales important to humans, the paleoclimate of ice cores, the glacial system and local climate patterns were analysed from Mt Erebus Saddle. Mt Erebus Saddle lies in the pathway of the El Nino Southern Oscillation (ENSO) initiated katabatic surges across the Ross Ice Shelf and also of enhanced cyclonic activity from the Southern
... Ocean. Ice core records from Mt Erebus Saddle are likely to show strong ENSO influence and therefore may provide a mean to reconstruct ENSO since its initiation in the early Holocene. A GPR/GPS (35MHz ) survey was made to map the bedrock topography and internal structure of the glacier. Two cores (200 and 160m) were extracted, measured and logged. Each 1m long core had its core temperature measured (within 5 mins of core recovery), weighed to calculate density and determine the depth of bubble close off and firn/ice transition and investigated for crystal structure, melt and dust/tephra layer occurrence. Analysis of volume, grain size and mineralogy was taken to determine the source and to infer wind pattern and strength. Small chips were used to study gas bubble properties (including porosity, gas bubble size and geometry). The borehole was measured for temperature and light penetrations after drilling. The borehole was measured for temperature and light penetrations after drilling. Several snow profiles were sampled with 1cm resolution for analysis on snow chemistry, isotopic composition, dust content and mineralogy. The ice cores and snow samples were measured for major cations, anions and methylsulfonate, trace elements, oxygen and hydrogen isotope ratio, gas analysis in ice core bubbles (CO2 and CH4), dust concentration and mineralogy, Si detection and tritium concentration and dating the ice core. Three snow stakes, 6m long were anchored into the ground to measure the accumulation rate at the drill site as the topography promotes strong winds leading to significant compaction of the surface snow.