In The Field

Earth System Science: to the coldest bit of the pole

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

http://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

http://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.

Comments

There are currently no comments.