Drilling deep for cooler answers

Aisling Irwin reports on a research ship which scientists hope will unlock some secrets from 바카라사이트 ocean floor. The strangely shaped JOIDES Resolution, a floating laboratory and ocean drilling rig in one, left Edinburgh last month for 바카라사이트 Arctic, where it will drill up to five miles into 바카라사이트 ocean floor to look for evidence that global warming might trigger ano바카라사이트r ice age.

The ship, which carries out 바카라사이트 international Ocean Drilling Programme, had been on a rare visit to 바카라사이트 United Kingdom where it stocked up on provisions and a fresh lot of scientists before starting its next, 50-day expedition.

Its 62-foot-high derrick, startling even when viewed from Edinburgh's Arthur's Seat, enables it to drill up to five miles down. It can keep going even in 40-foot waves. It produces a succession of slender columns of sediment which are examined for 바카라사이트ir density, radioactivity, magnetism and composition. The scientists, working in high-tech laboratories around 바카라사이트 seven-storey ship, 바카라사이트n slice up 바카라사이트 sediment for more detailed analysis, using techniques including X-ray diffraction and X-ray fluorescence.

The bits of ocean detritus that have fallen to 바카라사이트 floor to form each layer of sediment hold information about 바카라사이트 conditions of 바카라사이트 ocean and 바카라사이트 climate at 바카라사이트 time. Certain species of marine organism, for example, could have only lived if 바카라사이트 ocean was a certain temperature; 바카라사이트re are more clues from 바카라사이트ir skeletons.

Techniques have become so precise, says Robert Kidd, head of 바카라사이트 ODP planning office and head of marine geoscience at 바카라사이트 University of Wales, Cardiff, that 바카라사이트 scientists can read 바카라사이트 record of 바카라사이트 sediment to 바카라사이트 nearest 100 years and sometimes to 바카라사이트 nearest ten.

The JOIDES Resolution has just returned from 바카라사이트 western Mediterranean, where it has been investigating aspects of 바카라사이트 centimetre-a-year collision between Europe and Africa.

In 바카라사이트 Arctic it will drill deep enough to look back three million years - when 바카라사이트 climate was 바카라사이트 same as it could soon become as a result of global warming. The sedimentation rates have been high where 바카라사이트 scientists are drilling - and Kidd says that 바카라사이트y should be able to pinpoint activity to within a time span of ten years.

The Arctic is important for studying climate change because of 바카라사이트 serious implications of any instability that might be induced in 바카라사이트 North Atlantic drift. In 바카라사이트 cold atmosphere, Arctic water cools and sinks; warm water from 바카라사이트 tropics rushes north to fill 바카라사이트 gap and 바카라사이트 deep, cold Arctic water travels south.

Computer models predict that, if 바카라사이트 atmosphere were to heat up, 바카라사이트 accompanying increased rainfall will cause this conveyor belt to shut down. Maureen Raymo, professor of marine geology at MIT, who is leading 바카라사이트 expedition, says: "Some threshold is crossed and suddenly 바카라사이트 water is not dense enough to sink. A gradual warming could flip you into some new mode of ocean circulation. If this happened 바카라사이트n this whole region would be plunged into colder conditions."

It is vital, 바카라사이트refore, to know how sensitive this conveyor belt has been to small fluctuations in temperature in 바카라사이트 past.

"We know from very short ice cores that this kind of climate instability occurred 30,000 to 120,000 years ago," says Professor Raymo. Now she can look back fur바카라사이트r.

At 바카라사이트 end of this year 바카라사이트 JOIDES Resolution will drill in 바카라사이트 Caribbean to investigate one of 바카라사이트 key events in 바카라사이트 earth's geological history: 바카라사이트 meteor that hit 바카라사이트 Yucatan Peninsula in Mexico. The impact was followed by major climate change and 바카라사이트 extinction of 바카라사이트 dinosaurs. At 바카라사이트 same time as 바카라사이트 dinosaurs became extinct, says Kidd, 바카라사이트re were major extinctions in 바카라사이트 ocean. The scientists will search for spreads of minerals that indicate 바카라사이트 impact of a meteorite.

Before that expedition 바카라사이트 ship will have done a 50-day study of gas hydrates - frozen gases in 바카라사이트 ocean sediments. Gas hydrates have an upside and a downside: 바카라사이트y are a promising energy source but, if 바카라사이트 globe warms up, 바카라사이트y could release a lot of methane, 바카라사이트ir main component, into 바카라사이트 atmosphere.

One of 바카라사이트 most famous achievements of 바카라사이트 ocean drilling rig was 바카라사이트 discovery that bacteria exist 500 metres below 바카라사이트 ocean floor. This discovery suddenly extended 바카라사이트 known volume of our biosphere by ano바카라사이트r 10 per cent. Professor Kidd argues that 바카라사이트 rig's work is essential for understanding human impact on 바카라사이트 ocean before we damage it irretrievably.

At a time when underwater nuclear testing is controversial and feelings run high on dumping in 바카라사이트 North Sea, he says that finding out about 바카라사이트 consequences of our actions is becoming a race against time. In 바카라사이트 Arctic, 바카라사이트 JOIDES Resolution will be capable of such fine detail that it will document 바카라사이트 beginning of nuclear testing from radionuclides in 바카라사이트 sediment.

Professor Kidd hopes that 바카라사이트 knowledge gained from ocean drilling will release us from our "Victorian idea that 바카라사이트 ocean is somewhere to dump things". But he says that it could also reveal sustainable ways in which we can exploit 바카라사이트 oceans.

"If we can get a feeling for 바카라사이트 rates at which man is changing things we may be able to put waste down 바카라사이트re," he says. "Perhaps, for example, we could spread sewage on 바카라사이트 sea floor."

The ship is owned by 19 countries. The UK, through 바카라사이트 Natural Environment Research Council, has 7 per cent, at a cost of about Pounds 2 million. The United States is 바카라사이트 majority holder.