Many residents of northeastern Maryland felt a series of tremors this afternoon, and Joe MulQueen figured the shaking his house took must have been an earthquake. "It sounded like an explosion, but the entire house shook," he said.

But area seismographs were quiet. The shakes were the result of explosions at the U.S. Army's Aberdeen Proving Ground. Base spokesman George Mercer said the blasts included three "static detonations" at the facility's Edgewood Area. "And they were loud," he said.

A temperature inversion - a layer of warm air atop a layer of cold air at the surface - caused the sonic energy to reflect back to the ground rather than dissipate into the sky above. That just made matters worse, he said.

The noise and shaking was heard and felt from Perry Hall to Middletown Del. Mercer took 30 calls from concerned citizens. About 20 of them were complaints, the rest just expressions of concern and curiosity. 

There is more on the incident at Baltimoresun.com and there will be an article in Wednesday's print editions. Break a buck and buy one. Our kids gotta eat, too.