The T-shirts say it all: Keep calm and polka on.
It has been almost three years since a 5.6-magnitude earthquake struck Prague, Oklahoma, buckling a highway, cracking structures and rattling nerves. It was the largest earthquake ever recorded in the state.
City workers in Prague, a community of 2,400 people about 45 miles from Oklahoma City, wore the “Keep calm” T-shirts in May ahead of the heavily Czech-American community’s annual heritage festival.
It’s good advice. The Oklahoma prairie is rumbling like never before. Like residents across the state, the people of Prague have had to adjust to constant earthquakes. In the first half of 2014 alone, there were 211 earthquakes at or above 3.0 magnitude in the Sooner state, crushing the record 109 set in 2013. For three decades prior to 2009, Oklahoma measured one to three quakes 3.0 or higher per year.
On a Thursday in late June the region was hit by five quakes stronger than 3.0 — all in one morning.
Scientists link the seismic activity to the injection of wastewater into the earth, a process that follows the fracking of rock formations for oil and natural gas.