By Alicia Chang
AP Science Writer
LOS ANGELES — With the evidence coming in from one study after another, scientists are now more certain than ever that oil and gas drilling is causing hundreds upon hundreds of earthquakes across the U.S.
So far, the quakes have been mostly small and have done little damage beyond cracking plaster, toppling bricks and rattling nerves. But seismologists warn that the shaking can dramatically increase the chances of bigger, more dangerous quakes.