KTLX Birds Taking Flight, 19 Nov 2015 EarthquakeNot only did the earthquake overnight near Cherokee wake up people, it shook the birds from their roosts!

Posted by US National Weather Service Norman Oklahoma on Thursday, November 19, 2015

Early Thursday morning, an especially strong quake rocked the earth near Cherokee, Oklahoma. The magnitude 4.7 earthquake wasn’t intense enough to cause any serious damage, but it did startle enough birds for a flock of them to appear on the National Weather Service’s Doppler Radar.

The technology is primarily used for tracking storms, but large clouds of birds and insects have been detected by such systems in the past. This instance was especially remarkable in that it was the direct result of a seismic event. 

Earthquakes have been occurring in Oklahoma with increasing frequency and intensity in the past few years. In 2014, the state saw 585 magnitude 3.0 or higher quakes compared to the 109 recorded in 2013. This month, Oklahoma has experienced more magnitude 4.0 or greater earthquakes than any other month on record in the state, and Thursday’s event was the strongest seen since 2011. 

A study published earlier this year in the journal Science [PDF] suggests that many of these earthquakes have been the result of increased oil and gas drilling in Oklahoma. Another study from the Oklahoma Geological Survey [PDF] found that earthquakes are occurring at about 600 times the normal frequency that’s expected in the state. At that rate, Oklahoma's bird population may not be as surprised by the next one.

[h/t: Mashable]