A study of the crater left by the meteorite which many believe caused the extinction of the dinosaurs 65-million years ago is being opposed by activists who fear it could prove fatal to marine life.
The month-long study off the Yucatan peninsula in Mexico involves researchers from Cambridge University and Imperial College London, and US and Mexican universities.
It is due to begin as soon as the local authorities give the final authorisation, which is expected any day now.
The proposal is to fire compressed air from the survey ship Maurice Ewing into the sea above the crater and record the echoes the sound waves produce when they hit the rock.
Greenpeace and other environmentalist groups have vowed to stop the ”killer boat” going to work.
They argue that the sound will be so intense that it may make dolphins and other sea mammals deaf and leave them wandering around aimlessly until they die.
They are also afraid that damage will be done to to marine turtles feeding in the area, coral reefs nearby, and fish.
Ben White, who is leading the campaign, said on Wednesday: ”It could have a huge impact. The idea that you unload huge amounts of sound pollution into the living ocean and nothing happens is ridiculous.”
White (53) a member of the Animal Welfare Institute in Washington, said he was determined to force the researchers to shut off the airguns by getting into the water near the boat.
The survey vessel is currently just off of the coast, having loaded supplies in Panama.
The scientists involved in the programme insist that the activists are exaggerating the risks.
Mike Warner, of Imperial College, said: ”On any day of the week there are 30 or 40 boats like this working on commercial projects.
”What we are doing is not special or unusual or difficult. It is standard practice, just that we are doing it under the glare of NGOs.”
The University of Texas and the Autonomous University of Mexico are the other main parties involved in the study, which should have taken place last year.
But it was postponed when protesters persuaded the authorities to toughen up the permit requirements.
Among other things, the boat is now required to have independent observers on board with binoculars, watching out for dolphins.
Warner said: ”I think that the only possible problem now is that the noise in the local press will make somebody get political cold feet.”
The main aim is to discover the angle at which the meteorite hit and the direction from which it came, to help scientists form a better picture of what happened next: something still very much at the level of hypothesis.
The link made with the extinction of the dinosaurs, for example, is rooted in evidence that the two events occurred around the same time.
Some theorise that the meteorite caused a cloud of dust which blocked out the sun.
Others suggest that very hot material shot into the atmosphere and caused global fires.
Scientists say studying the crater could help clarify or discount all these theories, and might throw up new ones.
None of this interested White as he prepared to get under the airguns.
”There is some knowledge that we don’t really need to know,” he said. – Guardian Unlimited Â