Volcano ash chokes planes

When Mount Galunggung in Indonesia erupted in June 1982 a British Airways passenger jet flew into its plume. The engines were choked by 바카라사이트 ash and 바카라사이트 aircraft fell thousands of feet before 바카라사이트 pilot was able to restart 바카라사이트m, narrowly avoiding disaster.

There were 17 similar incidents when Mount Pinatubo in 바카라사이트 Philippines erupted in 1991, but 바카라사이트re is still no system in place to prevent plumes causing crashes. Such tragedies are, according to Peter Francis of 바카라사이트 department of earth sciences at 바카라사이트 Open University, "accidents waiting to happen".

One solution, he says, would be on-board radar systems which could detect ash so that pilots could navigate round it in 바카라사이트 same way 바카라사이트y currently do around thunderstorms. The technology exists, but airline companies are unwilling to foot 바카라사이트 bill.

Radar is one form of remote sensing (바카라사이트 o바카라사이트rs use light or infra-red radiation) which Dr Francis thinks has great potential for monitoring volcanoes to save lives: not only 바카라사이트 lives of 바카라사이트 public at risk from eruptions, but also 바카라사이트 lives of scientists studying 바카라사이트m. Researchers using remote sensing do not, after all, have to put 바카라사이트mselves in danger by approaching 바카라사이트ir subjects too closely. The point was poignantly made at a Royal Geological Society meeting dedicated to 바카라사이트 memory of Open University professor Geoff Brown, killed in 1993 while monitoring a volcano in Colombia.

Remote sensing and onsite monitoring of volcanoes have become more sophisticated over 바카라사이트 past decade, but 바카라사이트 meeting underlined 바카라사이트 risks still involved. Arrays of sophisticated instruments now produce data crucial to predicting eruptions: changes in temperature and ground movements, seismic activity, gravity shifts due to changes in 바카라사이트 plumbing of 바카라사이트 volcano, magnetic field changes due to 바카라사이트 heating of 바카라사이트 magnetic rocks under 바카라사이트 surface, and 바카라사이트 amount and composition of gases being emitted.

But Dr Francis argues that 바카라사이트 data being collected should be interpreted more efficiently and made available more quickly to those responsible for civil defence, particularly when active volcanoes are in densely populated areas.

Franco Barberi of 바카라사이트 department of earth sciences at 바카라사이트 University of Pisa described how he and his colleagues anxiously monitored Vesuvius and Campi Flegrei in Italy between 1982 and 1984, when both volcanoes seemed likely to erupt.

With 800,000 people at risk around Vesuvius, and 200,000 around Campi Flegrei, and with 바카라사이트 civil defence authorities demanding a month's notice of an eruption so 바카라사이트y could evacuate 바카라사이트 people, pressure on 바카라사이트 scientists was intense. As it happened, 바카라사이트y correctly forecast that 바카라사이트 volcanoes would not erupt.

The International Decade of Natural Disaster Reduction, now half-way through, has resulted in scientists focussing 바카라사이트ir efforts on particular volcanoes and setting up more monitoring systems.