![]() |
![]() |
![]() |
![]() |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||
![]() | |||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() | |||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
![]() |
You are in: Sci/Tech | |||||||||||||||||||||||||||||||||||||||||||||||||||
![]()
|
![]() |
Tuesday, 7 December, 1999, 12:26 GMT
Antarctica's icy origins
![]() It takes 30 days to drill 700m of rock
Scientists in Antarctica have uncovered when the continent's vast ice sheets formed and are warning that they could melt as consequence of global warming.
This could have implications for the future of the world's climate. Since the time when dinosaurs roamed a tropical Antarctic continent, the world has cooled down by 6.5 degrees Celsius. That was 65 million years ago, but some scientists say that global warming could reverse this gradual cooling in as little as two or three centuries. 'Year zero' "We are going to see a massive warming, there is no doubt about that," believes Mark Lavelle, of the British Antarctic Survey.
However, much of the recently-published research on Antarctic ice melting has presented a rather complex picture. Short-term satellite radar data has shown that the extent of the ice cover over the southern polar region is relatively stable, suggesting that any human-induced global warming that may be occurring has yet to have a major impact. The West Antarctic Ice Sheet, a focus for concern because most of it is on land, is slowly melting, but the most recent data suggests it could be another 3,000 years at current rates before it disappears completely. A clearer picture of ice melt may well come from a new Nasa satellite that is due to be launched in 2001. Digging deep The sedimentary rocks up to 350 million years old which are revealing Antarctica's past are being brought to the surface by the Cape Roberts Project.
The project is costing £4m and is an international collaboration. A number of boreholes have been drilled, up to a kilometre beneath the sea floor, itself up to 400m below the ice. However, with the temperatures in early December beginning to rise for the Antarctic summer, the Cape Roberts project is preoccupied with a more immediate form of warming. The ice which supports the drill rig is starting to weaken and melt, giving the team just a few weeks to drag all the equipment on it to the safety of the land. |
![]() |
See also:
![]() Internet links:
![]() The BBC is not responsible for the content of external internet sites ![]() Links to other Sci/Tech stories are at the foot of the page.
![]() |
![]() |
Links to more Sci/Tech stories
|
![]() |
![]() |
^^ Back to top News Front Page | World | UK | UK Politics | Business | Sci/Tech | Health | Education | Entertainment | Talking Point | In Depth | AudioVideo ---------------------------------------------------------------------------------- To BBC Sport>> | To BBC Weather>> ---------------------------------------------------------------------------------- © MMIII | News Sources | Privacy |