A senior American scientist has called on natural disaster experts to work towards predicting extreme events such as earthquakes and floods.

Forecasting when and where such events might occur has largely been dismissed as an impossible goal, but Charles Groat, director of the US Geological Survey, said prediction was not only possible but essential.

Professor Charles Groat issued his challenge to earth scientists at the annual meeting of the American Association for the Advancement of Science in San Francisco.

He called for urgent research on developing better monitoring and sensor technologies, to predict the exact time and location of natural hazards such as volcanic eruptions, earthquakes and hurricanes.

Right direction

Professor Groat's call runs counter to current scientific theory - that the complexity of natural disasters makes exact predictions impossible. But Professor Groat said researchers should not be discouraged from looking for effective prediction technologies.

"People didn't think that curing cancer or heart disease was possible and yet we've seen incredible steps towards that, and we did it because we held that out as a lofty goal," he told the meeting.

"I think we in the physical sciences need to accept that it may not be possible today or tomorrow, or in the next decade, but if we don't hold that up as an objective, we won't aim our science in the right direction to make it happen."

Professor Groat said that developing reliable methods of predicting natural disasters would require a dramatic rise in research funding. But he said the costs of such research would easily be recouped in terms of saved lives and infrastructure.