Replies to post #195462 on Tornado Alley (PROG)

[fuagf]

"The eight-week drill through 400 metres (1,312 feet) of ice, 600 kilometres inland
from Australia’s Casey Station in the continent’s east, will follow soon after."

I wondered what the deepest ice-core drill was so far .. not sure if this is it ..

European Project for Ice Coring in Antarctica

[...]

The European Project for Ice Coring in Antarctica (EPICA) is a multinational European project for deep ice core drilling in Antarctica. Its main objective is to obtain full documentation of the climatic and atmospheric record archived in Antarctic ice by drilling and analyzing two ice cores and comparing these with their Greenland counterparts (GRIP and GISP). Evaluation of these records will provide information about the natural climate variability and mechanisms of rapid climatic changes during the last glacial epoch.

The European Science Foundation EPICA Programme (1996–2005) provides co-ordination for EPICA drilling activities at Dome Concordia and Kohnen Station, which are supported by the European Commission and by national contributions from Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Sweden, Switzerland and the United Kingdom.

Deep drilling took place at two sites in Antarctica: Concordia Station at Dome C and Kohnen Station.

In 2008 the project received the Descartes Prize for Research.

Contents [...]

Concordia Station at Dome C


Plots of delta-deuterium against age and depth (from EPICA and Vostok). Note that the Vostok core is deeper, but does not extend as far back in time. Note also that the y-axis offset between the EPICA and Vostok cores in delta-deuterium is real: Vostok is a colder site, hence has more negative delta. Differences in the apparent age of events are likely to be inaccuracies in converting ice depth to age.

The EPICA and Vostok cores compared

This site (75°06'S 123°21'E, 3233 m above sea level, 560 km from Vostok Station) was chosen to obtain the longest undisturbed chronicle of environmental change, in order to characterise climate variability over several glacial cycles, and to study potential climate forcings and their relationship to events in other regions. The core goes back 740,000 years and reveals 8 previous glacial cycles. Drilling was completed at this site in December 2004, reaching a drilling depth of 3270.2 m, 5 m above bedrock. Present-day annual average air temperature is -54.5°C and snow accumulation 25 mm/y. Information about the core was first published in Nature on 2004/June/10

[...]

The core time scale is derived from the measured depth scale by a model incorporating surface snow accumulation variations,
ice thinning, basal heat fluxes etc., and is empirically "tied" at 4 times by matches to the marine isotopic record.

http://en.wikipedia.org/wiki/European_Project_for_Ice_Coring_in_Antarctica

So there is already a drill, completed December 2004, more than 8 times the intended depth of the
Australia, France, Denmark and United States Aurora Basin North project .. the higher snowfall

"“Seeking ice cores from this new area where there is much higher snow fall than other inland
sites provides a massive increase in the level of detail which lives within the ice,” Burke added."

in the area must be a significant factor .. anyway, note depth of the drill does not automatically mean older ice.