Volcanic eruptions pose a serious threat to aviation, but one that can be mitigated through the combined efforts of scientific specialists, the aviation industry, and air-traffic control centers. Eruptions threaten aviation safety when finely pulverized volcanic material (“ash”) erupts in large airborne clouds which cover long distances at airliner cruising altitudes. When an aircraft flies into an ash cloud results can include degraded engine performance (including loss of thrust power), loss of visibility, and failure of critical navigational and operational instruments. The best safety strategy is for aviators to know the locations of ash clouds and avoid them. Because ash clouds drift with prevailing winds for many days and thousands of miles, they potentially threaten air corridors that are far removed from the erupting volcano.
For example, each year approximately 25,000 large commercial passenger jets fly through a small area of airspace immediately surrounding the Mariana Islands, and more than 1 million planes fly from Asia to Australia and New Zealand. On May 23, 2003, Anatahan produced an ash cloud that disrupted regional and international air traffic on at least two days.
The volcanic-ash hazard to aviation is the subject of the upcoming 2nd International Conference on Volcanic Ash and Aviation Safety in June in Alexandria, VA.
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