Oklahoma’s string of man-made earthquakes continued with an new quake near the town of Cushing.
A magnitude 5.0 earthquake centered near one of the world's key oil hubs brought down building facades and shattered windows in a central Oklahoma city, rendering century-old buildings unsafe and raising concerns about key infrastructure.
A 5.0 quake may not seem like much for those who live in areas where earthquakes occur naturally, but Oklahoma is in one of the most geologically stable regions of the country. Until recently the largest quake on record was a 5.5 shake that hit in 1952.
That was before fracking. Injection of wastewater that results from oil and gas fracking causes earthquakes. Before 2011, Oklahoma had only three recorded quakes above 4.5. In less than five years, there have been twelve more. In 2016 alone there have been five large quakes, including a record-breaking 5.8 quake in September. And all of these are just part of a wave of thousands of earthquakes that have swept the region since injection of fracking wastewater began around 2010.
Because Oklahoma is in an area that’s been so historically stable, houses, buildings, bridges and other infrastructure are not built according to the earthquake guidelines that are in place for more seismically active regions. That means that a quake like the 5.0 in Cushing can be more destructive than might be expected.
Fearing aftershocks, police cordoned off older parts of the city to keep gawkers away late Sunday, and geologists confirmed that several small quakes have rumbled the area. Frazier said an assisted living community had been evacuated after damage was reported. The Cushing Public School District canceled Monday classes.
Oklahoma has had thousands of earthquakes in recent years, with nearly all traced to the underground injection of wastewater left over from oil and gas production. Sunday's quake was centered 1 mile west of Cushing and about 25 miles south of where a magnitude 4.3 quake forced a shutdown of several wells last week.