A small, 2.9 magnitude earthquake struck about 3 miles south-southwest of Danoco, Colorado, just north of Denver, on Friday morning.
According to the U.S. Geological Survey, the earthquake struck just after 6am. By 9:45am, 382 people responded to whether or not that they felt the quake to the U.S.G.S. Did You Feel It? response line.
A magnitude 3 earthquake, slightly stronger than what hit Colorado, has an energy release equivalent to 1,800 kilograms of explosives. That’s slightly less than the energy released through a large lightning bolt. Around 100,000 magnitude 3 earthquakes occur every year worldwide.
Earthquakes below a magnitude 2.5 can be recorded on a seismograph but generally go unfelt by people. People start to feel earthquakes when they reach between a magnitude of 2.5 and 5.4, though those quakes will only cause minor damage if any.