In April 2010, a little-known volcano on Iceland called Eyjafjallajökull erupted, spewing volcanic ash and steam almost 11 km (7 mi.) into the air.
The ash cloud, carried by the jet stream, wafted toward Europe. Airports all over Europe shut down. Flying through ash could cause engine trouble on aircraft and lead to disasters.
The cancellation of flights in Europe set off a chain reaction of flight disruptions around the world that lasted for six days in April and started up again in May.
The volcano’s eruption proved again how powerful natural events can affect the world.