Shaking all over ... the Pacific coast

[robkelk]

Southern California rocked by its strongest earthquake in 20 years - a magnitude 6.4 quake, preceded by a magnitude 4.3 quake a half hour earlier.

3 earthquakes registering between 4.5 and 5.6 magnitude detected within minutes of each other off B.C. coast

I hope folks "west of the Rockies" are okay.

[Labster]

Oh, I felt the 6.4 alright, but by about 5 seconds in I realized that there was going to be no danger to me. I'm so far away all I got was the longwave vibrations. Honestly, I'm a bit relieved because I know we've been overdue for a major quake, and this was not too bad.

For everyone else in California and Nevada, it was mostly pretty safe. The epicenter was near a deserted desert, with only a small city seeing damage, no reports of major injury. But, life is good. Building codes are good. The earthquake warning system is working as expected. Compared to the floods you've seen recently, this is barely even newsworthy; it's only a deep 6.4.

[robkelk]

Thanks.

I'm wondering whether quakes at two different spots on the same tectonic plate seam are something to worry about, if you live between those two spots. (Probably not, but I'm not a geologist, just a layman with one term of high-school geology.)

[Labster]

Well, I've only taken one upper division geology class (paleoclimates) but the answer is no. Or rather, you should have the same level of concern as two wildfires along the same plate boundary.

One of the things you get used to in geology is that the ground under your feet is not all that solid, under the pressures we see. For instance, continents float up because their crust is lighter weight than ocean crust. Even the largest quakes only can trigger more out to 200km or so. But the recent California quake is in the Basin and Range province, not all that near the plate boundary. Sure I could feel it here on the Pacific Plate, but that's more like hearing a firework than being near the flare.

[Labster]

Oooh, a 7.1 now. Wheeeeee!

Remember, this is a log10 scale, so a 7.1 is five times stronger than a 6.4. Same location though, near Ridgecrest in the desert. Shaky times at Ridgecrest High.

Definitely felt stronger, but still low rolling motion, so it felt like it was a long way away still. Enough to rock my car though, and set the chandeliers on a nice swing.

Will likely be still no damage in the major population areas. Closer in, well, we'll have to wait and see.

[Star Ranger4]

And not felt at all down in los angeles

[Labster]

Were you driving?  Cause people felt it.  I mean, I was watching TV when the system at CalTech reported an incoming 5.1 from the same fault, and I even felt that, if only barely.  And Ventura is a bit further than LA from the active fault zone.  But the 7.1, that was a fun one at my distance.

[Star Ranger4]

NOpe. apparently EVERYONE but me felt it.

[Bob Schroeck]

Don't feel like you're all alone. I missed the earthquake that hit NJ in 2011 (2012? I can't remember now) -- I was getting coffee in the break room and when I got back my co-workers were like, "did you feel the earthquake?" "What earthquake?" "The one that just hit a few minutes ago." "Nooooo...?" It wasn't until later in the day that I was sure they weren't kidding me.

[Star Ranger4]

To be honest, It has almost been a badge of Honor. Slept through MANY quakes that rumbled through the greater Lost Angeles area over my lifetime. The only one that woke me up to the point of concern was the whittier Narrows quake, because I was a) VERY close to the epicenter, and B) my apartment at the time was on risers over the parking area. So, yeah. SPend the rocking and rolling trying to decide if I needed to get myself and my GF at the time off the overhang and into real cover.

For those of you who don't google, that means I was about 13 miles from the epicenter. Last Quake I actually REMEMBER feeling. (sylmar I have testimony from my parents about sleeping through, Whittier Northridge I think I woke up long enough to go Oh, quake not a threat and go straight back to sleep. Also for the record I did that back on 09/11/2001 when I woke up, turned on the TV, saw one of the towers fall and went back to sleep thinking I was still dreaming)

[classicdrogn]

As a kid in New Hampshire, I was very disappointed to wake up after having fallen asleep on the couch one day to discover I'd missed an earthquake. Still living in the northeast, the only time I've noticed the floor shaking is when I'm inside a particular building and lots of people are walking around... I'm not sure why this happens, but it's a six-floor steel frame and concrete industrial type thing, so lightweight construction isn't it.

[Inquisitive Raven]

Don't feel like you're all alone.  I missed the earthquake that hit NJ in 2011 (2012? I can't remember now) -- I was getting coffee in the break room and when I got back my co-workers were like, "did you feel the earthquake?"  "What earthquake?"  "The one that just hit a few minutes ago."  "Nooooo...?" It wasn't until later in the day that I was sure they weren't kidding me.

Is that the one with the epicenter in Virginia? The quake that damaged the Washington Monument? I was taking a nap when it hit, and apparently my mattress did a real good job of transmitting the vibrations. I think it woke me up. I definitely notieced it. 

@classicdrogn Maybe it's a resonance thing. That's been an issue with certain bridges and much more recently than Galloping Gertie.

[Bob Schroeck]

That sounds about right.

[Mamorien]

Don't feel like you're all alone.  I missed the earthquake that hit NJ in 2011 (2012? I can't remember now) -- I was getting coffee in the break room and when I got back my co-workers were like, "did you feel the earthquake?"  "What earthquake?"  "The one that just hit a few minutes ago."  "Nooooo...?" It wasn't until later in the day that I was sure they weren't kidding me.

Is that the one with the epicenter in Virginia? The quake that damaged the Washington Monument? I was taking a nap when it hit, and apparently my mattress did a real good job of transmitting the vibrations. I think it woke me up. I definitely notieced it. 

@classicdrogn Maybe it's a resonance thing. That's been an issue with certain bridges and much more recently than Galloping Gertie.

I remember I was sitting at this very computer; the floor seemed to dip out from under me, and my office-chair may have rolled backwards.

[Dragonflight]

Ottawa's not known for its earthquakes, but I recall one about a decade back. I remember it largely because I was in the washroom of a modern office building, five stories up. The moment everything started shaking, and I could feel the building shift under me, I could only sit there on the toilet and think "This is a really crappy way to go..."

[Rajvik]

never really experienced a quake, even though they said there was one just up the road a couple years ago, minor thing, didn't even hit 4.0

[Black Aeronaut]

When I was living in Bremerton I got to ride out a 6.2 (I think? Epicenter was somewhere like Everette or something.) Weirded me out at first because for a moment it sounded like someone had fired up a bulldozer right next to our house and was starting to rev it.

And then the shaking REALLY started.

The place we were living in was this old house with a basement, regular floor, and dormered second floor. I was up in my room on the second floor when it happened and there was an old brick chimney happened to run straight through the middle of my room. Lemme tell you, I was keeping an eye on that thing for the entire fifteen seconds it lasted!

[Bob Schroeck]

Come to think of it, there was an earthquake I did notice -- the one that struck the NYC area on Saturday, October 19, 1985. I was sharing an apartment in Jersey City with a friend from college at the time, so I was actually quite close to the epicenter. I clearly remember being shaken awake at about 6 AM, wondering briefly what was going on, then saying to myself, "oh, it's just an earthquake" and rolling over to go back to sleep.

I apparently have a very high tolerance for earthquakes.

[DHBirr]

One awakened me in the small hours of the morning somewhere in the first half of 1992.  I was living off-post in Barstow, California.  It didn't seem to be much as quakes go, at least not where I was, and I don't recall any furor about it later.  I barely had time to get out of bed and stumble over to the bedroom doorway, which I'd always heard is a comparatively safe place, before it was over.  After a few minutes waiting for any possible further tremors, I basically said, "Meh," and went back to bed.