The U.S. Geological Survey’s annual forecast maps for the first time include human-induced earthquakes alongside natural temblor hazards, with Oklahoma
leading Midwestern states in shaker probability. America’s midsection has experienced an uptick in quakes due to part of the hydraulic fracturing process:
Wastewater from the fossil fuel extraction is pumped deep into the ground, causing faults to separate and slip. Since 2009, tremors in mid-America of at
least magnitude 3.0 have increased from a couple of dozen to hundreds annually. In recent years, Oklahoma has had more magnitude 3.0 quakes than
California, says Michael Blanpied of USGS, including its two largest ever recorded: a 5.7 magnitude in 2011 and a 5.8 magnitude in 2016.