The tremor caused by two sonic booms around noon in Ocean City is visible in the helicorder record.
Residents on Maryland's Eastern Shore and Coastal Delaware reported earthquake-like tremors earlier this afternoon that shook the ground and rattled windows. While officials were initially puzzled, the booms are now being attributed to supersonic flights.
Social media was abuzz this afternoon here on the coast as people took to their accounts to report earth-shaking tremors that rattled Ocean City and parts of Coastal Delaware as far north as Lewes and Rehoboth Beach just before noon.
Officials were confident that it wasn't an earthquake, but they weren't quite sure what it was.
The Maryland Emergency Management Agency confirmed that the tremors were caused by a sonic boom stemming from two flights out of Naval Air Station Patuxent off the Atlantic coast.
The disturbance registed on seismographs all over the region.