SAN DIEGO (KGTV) — From North County to Point Loma, San Diegans reacted on social media after loud booms and mysterious shaking Friday morning. Dave Hussa felt it as his parents' house in Carmel Valley.
"There were two distinct episodes with windows shaking," said Hussa. "The first one was two abrupt, violent shakes that were maybe 10 seconds each. I said, 'Wow that feel like an earthquake. Mom and Dad, did you think that was an earthquake?'"
But the U.S. Geological Survey did not report any earthquakes near San Diego Friday, so some people think they heard explosions from military bases.
The Marine Corps base at Camp Pendleton told ABC 10News it, "cannot confirm the exact noise or shaking... but here at Camp Pendleton, we are conducting routine live-fire training with high explosive munitions that may be heard throughout any time of day."
The base also says atmospheric conditions can amplify these noises. So, the exact cause of the shaking and booms is unknown. But the National Weather Service says a cold, cloudy day like Friday creates perfect conditions for sounds like explosions to travel further than usual.
"So, the cold temperatures are the number one difference right now," said NWS Meteorologist Alex Tardy. "So what that means is the air is dense. And when the air is dense, it can slow down sound waves. Instead of the waves escaping into the atmosphere, it can trap them and keep them down closer to where we live."
The strange phenomenon happened during a rainy week.
"So there's plenty of moisture in the atmosphere, and that absolutely affects the travel of the sound," said Tardy. "The moisture allows it to travel further."
Camp Pendleton did not mention how long explosions on the base could last, but military officials say it's part of routine training.
