We have lived in Mission Viejo near the lake for the last three years and we are still perplexed by the sporadic, yet sometimes frequent, rumbling boomsthat rattle our windows and terrify our cats. (Friday) has been a particularly active day—I think it started close to 11:00 a.m. and has continued throughout the afternoon and early evening (several last heard around 5:30 p.m.)
We have heard several explanations, including: Disneyland fireworks, local construction projects, trucks running over manhole covers, garbage trucks, and exercises at Camp Pendelton.
I'm leaning towards Pendelton, but my (South Orange County)-native husband thinks we live too far to hear/feel them. Also, he's never heard them since he's gone most of the time during the week when they seem to be most frequent.
Any ideas what causes these booms? If it is Pendelton, do they release any info to the local community to let us know when they will be active in this way?
It may be hard to believe, but that booming sound is most likely coming all the way from Marine Corps Base Camp Pendleton. The base has been holding 10 days of 24-hour live-arms ammunition training that will continue through Aug. 30.
This training includes "high explosive munitions." That means they are practicing using mortars and possibly other cannons.