London: A cloud of dense ash from the volcano in Iceland resumed its havoc-making disruptions of European air travel early Monday, forcing aviation authorities to temporarily close important airports in the Netherlands and British Isles, including London Heathrow, Europe's busiest.
The airspace over Heathrow was ordered closed from 1 am until 7 am London time, the British National Air Traffic Control Services, or NATS, said in a statement posted on its Web site Sunday night. The restrictions also included Gatwick and London City airports and all airfields in Northern Ireland and parts of Scotland.
Later, Dutch authorities announced the closing of airports in Amsterdam and Rotterdam from 6 am until at least 2 pm.
The drifting ash, which can stall jet engines with potentially catastrophic results, also forced the closing of Dublin's international airport on Sunday night, until at least noon Monday.
"The high density ash cloud continues to move further south in the early hours of tomorrow morning," the statement said.
The shutdowns come a month after an ash cloud disrupted most air travel in Europe for nearly a week, forcing the cancellation of thousands flights, stranding passengers, damaging the continent's economy and raising questions about the inconsistent oversight of Europe's air traffic.
Met, the United Kingdom's national weather service, estimated that the ash spewing from the volcano now towered around 25,000 feet. The weather service expected that southwesterly winds Monday would blow the ash cloud away from Britain by Tuesday.
Pilots reported that in many areas, the cloud, which can potentially damage engines through clogging and abrasion, was visible to the naked eye and was described as "a grey-black layer."
The volcano causing the clouds, named Eyjafjallajokull, had been dormant for nearly two centuries before gently erupting March 20, 2010. The Icelandic Meteorological Office and Institute of Earth Sciences at the University of Iceland said Sunday that it had detected three small earthquakes beneath the volcano and "unusually" high lightning activity in the ash plume.
The institute also suggested that the volcano, which has been known to erupt continuously for two years, might not go dormant for some time.
"No major changes are seen in the activity," the institute said in a report on Sunday. "Presently there are no indications that the eruption is about to end."