Was there a warning that the eruption was about to happen for eyjafjallajokull?

Yes, there were several warnings prior to the eruption of Eyjafjallajökull in April 2010. Increased seismic activity, including hundreds of small earthquakes, was detected in the weeks leading up to the eruption, indicating that magma was moving beneath the surface. Additionally, researchers noted changes in the geothermal activity and the melting of glaciers, which hinted at an impending volcanic event. These signs allowed scientists to anticipate the eruption and issue alerts, although the scale of the subsequent ash cloud was still surprising.