Things are looking good for a Chinese project to attempt to find the oldest
ice in the Antarctic, according to presentations here.
The team aims to drill deep into the ice of Dome Argus (Dome A), smack in
the centre of the continent. This inaccessible site stands some 4,000 metres
above sea level and more than 200 kilometres from shore, and holds the
record as the coldest part of the continent, with average temperatures of
-58C.
A preliminary expedition there in early 2005 (see news in brief
https://www.nature.com/nature/journal/v433/n7026/full/433564a.html), which
entailed a dangerous 2-month round-trip tractor journey over crevassed ice,
extracted a trial 110 metre core from the top of the dome. This core has now
been partially analysed and helps to confirm a slow rate of snow
accumulation in the area: 1.5 cm/year on average over the last 10,000 years,
says expedition participant Xiao Cunde of the Chinese Academy of Sciences in
Lanzhsu. That compares to 2.1 cm/year at Vostok, for example, another famous
drilling site.
The result bodes well for the existence of very old ice at the bottom of the
more-than-3-km-deep cap of ice: it supports their previous estimate that the
ice could be more than 1 million years old, or possibly even 1.5 million
years old, Cunde told the meeting. The previous oldest samples have come
from the EPICA project, which has retrieved ice of some 900,000 years, and a
Japanese team may have million-year-old ice from Dome Fuji (see
https://www.nature.com/news/2006/060123/full/060123-3.html).
Everyone in the ‘polar’ session seems excited by this prospect – both for
the science and because China is in the lead. Big Chinese Antarctic projects
are rare to say the least. But right now China may be the only country in
the world willing and able to mount such a massive logistical operation.
They’re planning to return to Dome A to drill a 500 metre core in October
2007, and aim to build first a series of summer stations and finally an
over-wintering station at the site. I only wish I could go with them.