On the way to the oldest ice
The EU-funded Beyond EPICA project has successfully completed its second drilling campaign in Antarctica’s remote Little Dome C site. By analysing an ice core extracted from the Antarctic ice sheet’s depths, the project ultimately aims to reconstruct temperatures and greenhouse gas concentrations over the past 1.5 million years.
Success despite difficulties
In this second campaign, the project team has for the time being managed to reach a depth of 808.47 metres. At those depths, the climatic and atmospheric information preserved in the ice corresponds to the last 49 300 years. This major intermediate result was achieved following almost 2 months of hard work hampered by unforeseen technical delays and poor weather conditions. The ultimate goal is to drill down to 2 700 metres, which is the thickness of the ice sheet beneath Little Dome C. “This season has been intense but brought amazing results thanks to the team’s gigantic efforts: they worked tirelessly for two months at the Little Dome C camp. They first tested the equipment, and then progressed down to the remarkable depth of 808 meters and collected high quality ice cores. This will be the starting point for the next Beyond EPICA drilling season,” states Dr Carlo Barbante from the Institute of Polar Sciences of Beyond EPICA project coordinator the Italian National Research Council in a press release posted on the project website. The team started by completing the installation of the deep ice drilling system and fine-tuning it to continue the drilling operations begun in the first campaign. They adapted the drilling system of German project partner Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) to achieve the best results for deep ice coring, using 3.5-metre-long drill barrels. However, in the campaign’s final days, the researchers tested 4.5-metre-long drill barrels, retrieving a single 4.52-metre ice core. Dr Rob Mulvaney from British Antarctic Survey of project partner United Kingdom Research and Innovation and AWI Prof. Frank Wilhelms explain: “This is a significant achievement for the AWI drill system: this is the longest core ever drilled by a European project. Its significance lies in the fact that at greater depths, where the time to winch down and up the borehole increases incrementally, being able to recover longer cores in each run means that we progress faster with the drilling, and should cut the time needed to reach bedrock, and the Oldest Ice.” The ice holds the secrets of Earth’s temperature and atmosphere over centuries and millennia. By analysing the ice cores, the Beyond EPICA (Beyond EPICA Oldest Ice Core: 1,5 Myr of greenhouse gas – climate feedbacks) scientists will be able to gain information on the greenhouse gases contained in the atmosphere in the past and insight into how temperature evolved over time. “We believe this ice core will give us information on the past’s climate and the greenhouse gases in the atmosphere during the Mid-Pleistocene Transition (MPT), which happened between 900,000 and 1.2 million years ago,” states Dr Barbante. “During this transition, climate periodicity between ice ages changed from 41,000 to 100,000 years: the reason why this happened is the mystery we hope to solve.” For more information, please see: Beyond EPICA project website
Keywords
Beyond EPICA, ice, ice core, Antarctica, drilling, Little Dome C, greenhouse gas, drilling
