Walls rattled for half a minute.

Magnitude 3, 3 miles south of Julian. About 50 miles north of me.

Caltech:
https://scedc.caltech.edu/recent/Quakes/quakes0.html

Hearing 5.2 just south of Julian

I need totally disable that frickin earthquake alert on my phone!!

In that split second it took to realize what was happening, and the action was getting strong, that alarm starts going off and created sensory overload


Pretty much paralyzed me for another couple seconds. "Do we get out, are the walls swaying, what the fuck is that alarm on my phone?" (Check phone while still assessing motion and earthquake sounds) that delay…

quote:

I need totally disable that frickin earthquake alert on my phone!!

I was under the impression that earthquakes could not be predicted. So I don't quite understand the concept of an alarm for them.

^^^^
They report the actual time of the quake, which can be several minutes before it’s felt miles away.

quote:

Originally posted by gjgalligan:

quote:

I need totally disable that frickin earthquake alert on my phone!!

I was under the impression that earthquakes could not be predicted. So I don't quite understand the concept of an alarm for them.

Cannot be predicted. Theory is once the quake reaches a certain magnitude, the alert goes out. The further you are from the epicenter, the more time (a second or three) you have to prep. If you are close to the epicenter then when you start feeling the action and your brain is realizing it’s more than a sonic boom or heavy truck driving too fast near you, then the blaring alarm takes over your phone.

Aftershock just now. Long and drawn out this time with all the rumbling sound effects.

I got the alarm just as it hit here in OC. I initially thought the alarm was an amber alert or such. I looked at the phone and saw it was an earthquake warning just as I started feeling the floor move and heard glassware rattling in the cupboards.

I’m in San Diego. Didn’t notice anything.

Received the text alert that the earthquake occurred and to expect shaking. A few moments later it came as gentle rolling for 15-20 seconds and then tapered off.

My sister lives in north San Diego and it rattled her house pretty good.

At my condo was a jolt back and forth vs a rolling one. North county San Diego.

I was with my wife in the ED at the Kaiser SD Med Center. Figured this new hospital should be good in a quake— but the whole building did shake. Earthquakes not as common in San Diego as up north.

I was working in the office just south of Los Angeles. My phone alerted me and then I felt some slight waves. We have a recent transplant in the office and he didn’t feel it. I took it as a good opportunity to discuss protocol and preparedness.

Makes one wonder...when will the "big one" strike?

quote:

Originally posted by Warhorse:
Makes one wonder...when will the "big one" strike?

Seismologists always say we're overdue and while we wait, we constantly have much smaller quakes spread over the region leading people to ask if that relieves enough tension to avoid the big one.

The answer is that it won't.

I took a protracted EMS class and we spent an entire day covering The Big One and what to expect. Using a model based on the San Andreas fault SE of Palm Springs near the Salton Sea, it would only take less than a minutes for the movement and wave to reach the Greater Los Angeles area, depending on the type of wave.

Beyond damaged or collapsed buildings, the real fear is collapsed freeway overpasses. There are less than 10 major freeways into SoCal and San Diego and if overpasses collapse, there's no way to bring in resources. There are smaller highways but nothing that would allow sufficient supplies to come in.

Most people in SoCal know about preparing for disasters and to have at least three days of food but not many do so the authorities are expecting mass looting in certain areas.

To keep things from getting that far, they have been focusing on seismic hardening for overpasses and other highway structures.

I got off a bit beyond your original question but that's what we can expect when the big one hits.

I was in Reno at a convention in 89, the Loma Preita earthquake hit which is south of SF, 6.9, we felt it in the convention hall in Reno.

It collapsed a section of the 880/Nimitz freeway, lucky it didn't collapse much on the peninsula as the World Series was going on at Candlestick park, which is south of SF on the 101. The series being on that side of the bay probably saved a bunch of lives as the freeway that collapsed is on the Oakland side.

Part of the Bay Bridge fell, top level, if traffic had been at the high point it would have been worse, but to your point, the freeway side on Oakland was shut down, as was the bay bridge.

I was in the Northridge quake.
I've always kept emergency supplies, particularly water.
How an earthquake feels depends on the composition of the land one is on, as well as that between you and the epicenter.
I would never move to San Francisco, but if I did I would avoid the areas built on artificial fill for an absolute.

quote:

Originally posted by Flashlightboy:

quote:

Originally posted by Warhorse:
Makes one wonder...when will the "big one" strike?

Seismologists always say we're overdue and while we wait, we constantly have much smaller quakes spread over the region leading people to ask if that relieves enough tension to avoid the big one.

The answer is that it won't.

I've also wondered whether smaller quakes relieve enough tension to avoid the big one.

Southern Missouri also has a big fault known as the New Madrid.

Predictability

Unlike the West Coast where major quake activity is more predictable based on measured movement at tectonic plate boundaries, New Madrid is located near the center of the North American Plate. The crust in the central U.S. is being deformed / strained slowly in contrast to conditions in the west. What has been learned in studies there may not apply here.

Another contrast is due to a difference in geological characteristics. The harder, colder, drier, less fractured crust in the central U.S generates greater shaking over larger areas than quakes of comparable magnitude in the west. Shake and damage areas are up to 20 times larger than similar West Coast quakes.

Earthquakes cannot be predicted. The likelihood or probability can be calculated from patterns of recurrence in the past. Based on evidence of quake activity found in geological features, scientists estimate that the average interval between magnitude 7.0 quakes or greater is approximately 500 years. This is more frequent than expected.

Projections

The USGS has projected that for an earthquake of magnitude 7.5 to 8.0, the probability for occurrence is approximately 7-10% over the next 50 years. For a quake of 6.0 to 7.0, the probability is 28-46% over the next 50 years.

To date, the earthquakes of 1811-1812 remain 1 of the most remarkable seismic events in history. On the USGS list of the 20 largest earthquakes in all 50 United States, the 3 main shocks are ranked #18, 19, and 20 (Alaska dominates the top of the list). On the list for the continental 48 states, the New Madrid main shocks are ranked #5, 6, and 7.

https://www.sccmo.org/705/About-the-New-Madrid-Fault

quote:

Originally posted by ChuckFinley:
I would never move to San Francisco, but if I did I would avoid the areas built on artificial fill for an absolute.

South of Market, anything East of Sansome St. and the Marina which is where most of the damage and notable imagery came from during the '89 quake.
I was coming out the Embarcadero BART/Metro station when the quake hit; as I'm going up the elevator to street level it stops suddenly, the wall panels started popping in/out and looking up I could see the buildings swaying all around. The stone/cement facades of all the building panels would scrape and pop, dust filling the air from all the friction, the wires to the Muni bus lines along Drumm St swayed and snapped. A building on Front Street had its entire facade collapse exposing all the offices, looked like a movie-set, the long walk home helped calm my nerves. By the time I got home, you could smell the fires burning in the Marina. Phone lines worked after several hours, and we all packed up to go help at my Uncle's Pharmacy, not only had all the front windows shattered or, cracked but, merchandise was all over the place.

quote:

Originally posted by corsair:

I was coming out the Embarcadero BART/Metro station when the quake hit; as I'm going up the elevator to street level it stops suddenly, the wall panels started popping in/out and looking up I could see the buildings swaying all around.

I was in an elevator car on the 5th floor of a building in Livermore when it hit. The car stopped moving down, and in a surreal moment that seemed like an eternity, I somehow knew what was happening. I heard what I believe was the sound of the cables holding the elevator car slapping together, and then the shaking of the car back and forth. I didn't fall down, but did lose my balance and fall against the wall. I just stared at the light indicating floor level and started to think how I was going to get out, if it didn't start moving. It did start moving, came to the ground floor and the door opened. I dived under a heavy oak table in the lobby of the building. Once things stopped moving, I came out. I recall an older secretary come out of her office, ashen. She grabbed my arm like a vice grip and said, "I will never work late again!" Had no idea how bad it was until I came home and called my mother to let her know I was ok, as I figured there would be a blurb about an earthquake in CA, and she would be worried. She told me how bad it was.