It was a big shock but it brought the community even closer, said Tinley Park High School Principal Theresa Zielinski.

Compressive faults occurred after principal earthquake with slow variation in propagation and release of stress wave, this might lead to higher after shock intensity and longer duration.

The results show that the principal factors effecting the smash district and the blasting cavity radius are strength of the shock wave, the characteristics of rocks and radius of the hole.