I would have been more entertained if someone had removed the television and left me staring at the wall for 90 minutes. Brittany Murphy is impressively unconvincing as a seismologist and only barely convincing as a human woman. The special effects were the best bit, but because they were so overused and poor, and therefore rather funny. The acting was dreadful across the board and I felt cheated and robbed that the entire cast didn't all perish and put themselves out of my misery. I agree with Luke Baldock about the extras spontaneously combusting as a result of the volcano - I sneeze with more vigour. Oh, and a C130 with one knackered engine can still take off and land with no problem, and a helicopter won't keep up with F-22s.
Don't bother watching this film. Go have dental surgery instead.