Volcano’s ash cloud threatens air traffic

DUBLIN — Iceland’s clouds of volcanic ash are menacing European air traffic again, but transport chiefs insisted Tuesday they are learning from last month’s crisis and won’t let the hard-to-measure emissions ground their continent again.

Rising volcanic activity spurred aviation authorities in Ireland, northwest Scotland and the Faeroe Islands to shut down services Tuesday after a two-week hiatus. Their airports reopened several hours later, once the densest ash clouds had passed over their airports and back over the Atlantic.

But soon a new wave of engine-damaging ash was approaching, forcing Britain’s Civil Aviation Authority to announce that airports in Scotland and Northern Ireland had to cancel all services beginning at 7 a.m. today. The British authority said the prevailing winds would probably continue to push the threat southward, “potentially affecting airports in the northwest of England and North Wales tomorrow” — but missing the key European air hubs in London.