Man-made quakes have hit once stable regions in central and eastern US . These include Arkansas , Ohio , Kansas , Colorado , Oklahoma and Texas . Some were caused by injection of wastewater which can activate faults . Many of faults awakened by drilling have not moved in millions of years .
Man-made quakes have hit once stable regions in central and eastern US . These include Arkansas , Colorado , Kansas , Ohio , Oklahoma and Texas . Some were caused by injection of wastewater which can activate faults . Many of faults awakened by drilling have not moved in millions of years .