The report shows that 7 million people live and work in areas east of the Rockies that have the potential for damage from human-induced quakes. In fact, in portions of Oklahoma, the risk is just as high as portions of California.
Fracking -- shooting a high-pressure mixture of mostly water and sand against a rock formation until it fractures and sand fills the factures, forcing crude oil out of the rock formation -- is the main reason, Oklahoma is now in such a high-risk category. Wastewater disposal from the oil and gas industry is being injected into deep underground wells that's triggering quakes.
Out of the six states with the highest risk of human-induced quakes, Texas and Oklahoma have the highest population exposed to potential damage.
The USGS has labeled places in Oklahoma and California with a 10%-12% chance of experiencing damage from shaking in 2016.
