How Fracking Wastewater Is Tied To Quakes

For decades, scientists have known that activities like mining, drilling and building dams can create earthquakes. As early as the 1960s, observers noted that deep-earth gold mining changed the stresses in rocks and caused earthquakes. Above, miners drill into the rock at the Sub Nigel East Gold Mine in Johannesburg in 1961, more than 6,000 feet below ground.