The thunderous boom that some people near Los Alamos National Laboratory heard Wednesday was a detonation at a lab blast area.
It was one of several hundred explosions lab crews set off each year, but it was louder than usual this time.
"While the vast majority of these [blasts] use small amounts of explosives, some are large enough to be heard off site,” lab spokesman Kevin Roark said in an email.
The lab conducts the controlled blasts under strict regulations and assesses atmospheric conditions to reduce the chance of “sound intrusions,” Roark said.
He didn’t say what the purpose of this blast was. But the lab often sets off explosive charges for research and tests, including to determine how effective a bomb detonator is.