The last time I actually felt an earthquake was about 50 years ago.

Tonight at about 5 pm my wife got off the sofa and it hit. Our floors shook, we heard a boom, and I teasingly blamed her - she’ll never let me forget that one.

Seriously we have the new Madrid fault south of us in Cape Girardeau. I believe it was the 3rd highest recorded earthquake in US history.

This one was centered just 11 miles from our home.

quote:

Originally posted by h2oys:
The last time I actually felt an earthquake was about 50 years ago.

Tonight at about 5 pm my wife got off the sofa and it hit. Our floors shook, we heard a boom, and I teasingly blamed her - she’ll never let me forget that one.

Seriously we have the new Madrid fault south of us in Cape Girardeau. I believe it was the 3rd highest recorded earthquake in US history.

This one was centered just 11 miles from our home.

I was outside firing up the grill and heard a huge boom but didn’t feel anything. I went inside and asked the wife if she noticed anything, not a thing.

I’m really curious what the source of the boom was.

California guy checking to see if you guys are ok after a 2.8

2.8
Me tossing my shoes in the closet causes a 2.8

Like I said, my wife got off the sofa, there was a big boom, and the floor shook. That’s my story and I’m sticking with it

Ps: thank goodness she doesn’t have a sigforum account.

My 12 year old called me to tell me the house shook. He said it was like a loud thunder clap, but longer. When I got home, I saw on the news it was an earthquake. When I told him what it was, he was pretty excited he felt it.

Now our local news is bringing up the 1811 to 1812 earthquakes which ranged from 7.0 to 7.8.

Where’s Iben Browning when you need him?

The house shook. The glass fixtures almost broke. Dishes shifted. People flew out of homes. And in a moment it was over.

Felt nothing but heard a deep thump if not a boom.

quote:

Originally posted by h2oys:
I’m really curious what the source of the boom was.

The initial compression wave (p-wave) during a seismic event can sometimes be heard, particularly if there's an inversion layer in the atmosphere for it to reflect off of. The frequency of the wave is usually at the low end of human hearing, but sometimes it is audible. Animals tend to be more sensitive to it. You'll often hear reports of animals acting strangely just before a large quake hits, and it's speculated that they are responding to the initial p-wave arrivals before the surface waves (i.e. ground motion) hit.

^^Yep indeed. I was walking down the sidewalk in October 1989 and heard this high-pitched whine. I knew what P-waves were, so I said to myself, "we're about to get a big one". Sure enough, a couple seconds later the 6.9 Loma Prieta hit, almost knocking me to the ground.

I was sitting in a chair and heard a loud thud and my chair seemed to bounce a bit. Rather creepy.

I was in Hawaii in 2018 during the long running Leilani Estates flow and stationed at the summit of Kilauea. Underground magma draining away to the coast caused the caldera to subside very consistently- every single day there would be a good sized quake between 6 and about 6.3 magnitude. The entire caldera would drop about 6 feet- if you were near the summit it was the best show; you could hear an audible “knock” sound followed by several seconds of shaking while the caldera settled.

It was a very cool experience and I tried to time being there which was fairly easy; the cycle was just over 24 hours. After each big temblor there would be a few hours of barely perceptible shakes that over the period would grow stronger and more frequent culminating in the big shake with the “knock” sound.

quote:

Originally posted by jaaron11:

quote:

Originally posted by h2oys:
I’m really curious what the source of the boom was.

The initial compression wave (p-wave) during a seismic event can sometimes be heard, particularly if there's an inversion layer in the atmosphere for it to reflect off of. The frequency of the wave is usually at the low end of human hearing, but sometimes it is audible. Animals tend to be more sensitive to it. You'll often hear reports of animals acting strangely just before a large quake hits, and it's speculated that they are responding to the initial p-wave arrivals before the surface waves (i.e. ground motion) hit.

Thank you for the explanation!