I just sat through a big earthquake here- East Med

[thinkpadx]

i am glad you all are safe!

[Stevo]

It's surprising to me here in Southern California how many people are totally unprepared for a major quake from any one of the many known or unknown active faults criss-crossing the area. The L.A. basin is overdue for a major disaster. Luckily, the eastern San Diego area is probably as far from any really active faults as possible in SoCal--the Elsinore fault about 50 mi NE has about a mag 7 maximum credible quake and breaks maybe every 300 years or so, so we'd see some shaking here, but no buildings collapsing.

Downtown San Diego has the Rose Canyon fault running directly under it, but that one probably breaks more on a time scale of thousands of years instead of hundreds.

[Sparky]

I've lived through many earthquakes here, but its hard to get used to them. At least I took this one sitting on a chair in front of my computer, and I didn't break a sweat.

[JayM]

The problem with earthquakes is they happen suddenly and unexpectedly. For a year after the Bohol earthquake every time a car drove past and vibrated the ground a bit my adrenaline started flowing and I thought "here we go again." Not to mention the aftershocks that went on for almost a month. Talk about PTSD! I'm pretty sure I must have been wandering around downtown Seattle with that thousand-yard stare after the Nisqually one too. At least with typhoons you know they're coming and can take steps to prepare so you feel like you're doing something and have a bit of control over your situation. With earthquakes you're pretty much helpless other than general preparedness, i.e. having a stash of fresh water and canned goods put away for emergencies. Even having an evacuation plan doesn't necessarily do any good because the streets along your planned route may be impassable. You pretty much have to just ride them out and pray.

[Huckleberry Finn]

i am glad you all are safe!

Thank you :)

Very sad to read about the loss of life both sides of the border (Greece/Turkey).

Thank you, too and me, too .

What I was surprised is: In that region (Aegean Sea) it's something that always happens but we never feel them, just hear on news. But when we felt it and Sparky told about that I was shocked, said to myself "then, the Aegean Sea again, but how ?? ... that big !? .. "

In 1999 I was just going to bed, listening to the news at 03:01 am .. And ... 7.8 .. one of the most demonstrative ones, lasted more than 60 sec. and that made it even worse .. (the speaker woman also got caught on-air)

Also the type of land (soil or rock) changes the effect, say, soft soil (and such) makes an amplifying effect in general ...

[JayM]

Also the type of land (soil or rock) changes the effect, say, soft soil (and such) makes an amplifying effect in general ...

It's called liquifaction where soil, especially if waterlogged, acts like a liquid during an earthquake and loses all stability. I suppose sand even if dry would do the same thing, but who would build buildings upon sand? (Hopefully no one.)

[metreo]

https://www.youtube.com/watch?v=1n3n2Ox4Yfk

Ithaca poem read by Sean Connery RIP

[Stevo]

Lots of buildings are built on soft sediments that do quite badly in major quakes--sometimes that's the only choice, or they are grandfathered in. Examples are everywhere--Mexico City, fill along San Francisco Bay, beachfront apartments in the SoCal area...

I'm sure most people know that the Pacific NW is due for a magnitude 9 megathrust quake and tsunami on the scale of the 2004 Sumatra and 2011 Japan disasters sooner or later. We even know exactly the year, date, and hour the last one occurred in 1700, since the Japanese recorded the time and date of its tsunami hitting their coast.

[metreo]

Is that guaranteed to be in the vicinity of the Pacific NW or could it happen anywhere on the larger tectonic plate?

[JayM]

The fault is just offshore so the whole PNW could be affected. https://en.wikipedia.org/wiki/Cascadia_subduction_zone The Cascade Mountains are all volcanic and are related to the subduction zone from land from the Pacific plate being thrust underneath the continental plate. Plus there's another fault running right through Seattle and Elliot Bay: https://en.wikipedia.org/wiki/Seattle_Fault It all gets kind of complicated. Seattlites call it "the big one." Many or most people are prepared but also tend to be fatalistic about it at the same time.