Could Los Angeles withstand a “megaquake’?

BBC News ^ | 10 December 2013 | Last updated at 19:03 ET | Simon Redfern

[Carry_Okie]

Then I guess a 7.9 would really screw things up in LA.

That's why I called it to your attention. Recall the damage done by the Sylmar or Northridge quakes. One reason is that LA is built of concrete made of colluvial deposition from the San Gabriel Mountains, much of it dug out in Irwindale. It's easy to dig out and process, but it's crappy granite.

[ridesthemiles]

I lived in LA when the 1971 quake hit.

There are still buildings that have not been rebuilt from that quake.

Then the 1994 quake hit. When I visited in 2005, there were plenty of visible buildings still not repaired or inhabited.

There are also buildings that were never rebuilt after the Watts riots.

[Gaffer]

Thanks. I actually was in kind of a daze then. The quake hit while I was at a meeting with a lot of people at Stanford Research Intl.

When it hit, I went immediately for a doorway where I immediately got pushed out into the hallway by all the other people wanting that same space.

I was relegated to standing out in the hallway where I saw all the books from all the offices in the hallway come flying out into the hallway floor.

That night, I made my own earthquake detector in the 2nd story hotel room. An ashtray precariously balanced atop a beer bottle (from the hotel bar where booze flowed freely by candle light, BTW).

[John Valentine]

I didn’t witness my own birth either, but I’m 99.99% sure it happened.

[Haddit]

Both of those quakes were in the darkness. It takes a few tries to get back into the house and garage for coffee and camp stove. Every time you set foot in there, there is another aftershock.

Those of us that know quakes just pause for a moment to see if it is going to get stronger.

I was at work one time when a small quake hit. It was one of those earthquake proof factories that is on rollers and oriented to the fault lines. The higher up you go, the more exaggerated the shaking is. I asked the machinist downstairs how hard he felt it, he didn’t. He had just retired from the Navy.

[John Valentine]

It’s hard to know where to begin. There is nothing whatsoever “tricky” about looking at the natural world and finding evidence in its “physical material”. That evidence can tell us much not only about its present state, but also about the past.

As for Toba, there were plenty of people around to see the eruption, but no one nearby survived, and even if some had, they would all be dead by now, so their evidence would be discounted by you. The notion that the world came into existence at the moment of your birth is solipsistic and not the least bit scientific.

I think you are more than a little bit silly.

[Haddit]

I’ve wondered about that too. The 118 freeway was built with concrete that after a couple of years would just pop creating huge potholes. They blamed it on the gravel and repaved it with asphalt. But what about all the tilt-up buildings being made of the same stuff?

[Bender2]

Re: I certainly would not mind finding out if your theory is correct....

Well, Howie, if you wish... to move past theory here is some sportswear choices for ya:

......

......

And if that's not your style... I have the one I wear... all the time.

[Carry_Okie]

But what about all the tilt-up buildings being made of the same stuff?

Or bridges.

[Mike Darancette]

A repeat of the 1857 Ft. Tejon earthquake would be worse. But maybe a rupture along the southern San Andreas could shake the stuck portion (between Ft. Tejon and Parkfield) loose.

[Conservative4Ever]

Well lets see...starts at the Salton sea and moves north to LA. That would pretty much run through my front yard. Might make a few waves in the koi pond. The Lander-Big Bear quake a few years back was bad enough thank you. Watched my house *torque* while standing in a doorway as the quake was happening. Next day noticed a crack in the dirt road that started a few hundred yards north of my house, cross the street which ran east/west in front of my house and continue on across a 80 field across the street. Yep, about a 1 inch crack across the macadam.

[Mike Darancette]

That quake was a 7.9

Loma Prieta was a 6.9 magnitude.

[SamAdams76]

This is nothing compared to if Earth was to be sucked into a black hole.

[Mike Darancette]

Nobody saw Krakatoa erupt either. Well, nobody that LIVED.

There was a ship that survived the immediate Tsunami.

http://en.wikipedia.org/wiki/Governor_General_Loudon_(ship)

[maddog55]

I’m not a fan of Al Qaeda either it has to do with the whole enemies thing.

Based on your comment I’m guessing losing the liberals is ok but just not the conservatives so I’ll side with that.

[trisham]

It’s so much more dangerous in darkness, imho. Especially if one is asleep.

[Olog-hai]

And it never has a liberal bias?

Well well well.

[null and void]

Not when it comes to physical constants, math and engineering formulas.

[hattend]

My house is in Redding.

As long as the coastline stays more than an hour south and west of me, I don’t care.

[roadcat]

But I guess we’ve gotten increasingly dependent, and view such interruption as enormous suffering.

Loss of electricity can seem like no big deal (unless you go without for more than a week like we did after a storm). But consider what a quake can do to gas lines.

Very close friends of ours lost their house in the San Bruno gas explosion a couple years ago. Their home was right at the place where a gas line blew, and theirs was one of three homes to instantly be blown away. They were fortunate that mutual friends begged them to go out to dinner an hour before it happened, so they survived. Other neighbors perished. Their home on Earl Avenue was two blocks from the San Andreas fault line, but blame was put on the utility provider.

I'm just saying, a large quake could rip and rupture gas lines, causing major fires. Depending on the severity, there might be no escaping an explosion and fire. People never consider the gas lines underground when thinking about earthquakes.