Why did the Eyjafjallajökull volcano in Iceland begin as a passive eruption and become more explosive, emitting ash and shutting down air traffic in Europe?

In short, it was caused by 3,000 consecutive strong earthquakes. and caused by the freezing of lava causing glass particles.

Red clouds were seen at the volcano. The eruption was the result of intense seismic activity and a high rate of characterization in the weeks prior to the eruption. coupled with magma, which fuels the volcano

The second eruption occurred beneath the ice of a glacier. The cold water caused by the melting of the ice quickly cooled the lava and shattered the frozen lava into glass. This produces tiny glass particles which are carried in the ash spout. which that event As a result, airlines that leave Europe and enter Europe have to shut down for several days. coupled with the size of the eruption This is estimated to be 10-20 times the size of the eruption at Fimverduhaus. This resulted in a high-level atmospheric high-level of glass-contaminated ash plumes. which is dangerous for aircraft