Mexico's 7.2 Earthquake from a transit camera | Hacker News Reader

Mexico's 7.2 Earthquake from a transit camera

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The strategy of the 3 people huddling into a circle was interesting. I'm impressed they came up with that on the fly.

It looks weird to me. I think I would just sit down, but seeing what happened after maybe it's better to be on feet.

It's probably even hard to sit down or get up when the ground is shaking.

I was pretty close to a group of low to mid 6.x earthquakes in eastern California in 1980, across a couple of days.

For the strongest, I distinctly remember not being able to stand up. I tried, but kept falling down right on my ass each time. The amount of ground movement was quite surprising.

This is curious since I've seen people standing (kind of) and even running (kind of) in even stronger quakes, on video, as we see here.

I was in a deep canyon (with >4000 foot mountain walls around), so I'm sure the geology was interesting from an earthquake point of view.

The sounds were titanic; there were enormous rocks slides all around, and the mountains largely disappeared in dust, even as you could hear intense crashing and tearing sounds echoing back and forth.

If memory serves, nobody was killed, likely because of the parse population of that area, and also the stringent building codes. Also a lot of people got lucky, with so many rock slides going on.

A lot depends on how far you are from the epicenter and the kind of soil.

Definitely. Also the steep craggy valleys no doubt affected the strength of the S-waves.

"and even running"

Well when you are running you are mostly in the air, so you are only influenced by the movement of the earth while your feet touch the ground (which is still obviously a little problematic).

That makes perfect sense.

So, the next time I need to move my body somewhere during a large earthquake, running as quickly as possible should provide the best outcome. (:

Makes sense to me, didn't surprise me, and doesn't impress me either. I find it entirely a natural and logical response. Are you going to leave out one person who's in the very same sudden need and sudden distress as you?

well there was a routine earthquake drill the same day just hours beforehand.

Why did the guy in the car come out? Wouldn't it be safer to stay in the car as protection against things falling on your head?

I think the guy was a police officer, and it looked like he was calling for pedestrians to run away from the buildings before they fell.

Indeed-- car's sirens are going at the end & he's using a walkie talkie

Yes, he was. The comments are praising him for the amount of lives he saved.

Is a normal procedure on a earthquake

You have less awareness in a car of whats going on - for example you can't look around for falling things.

Now I'm not in an earthquake prone area, so I genuinely don't know.

But wouldn't the roof of the car provide some protection from smaller debris falling on you without you needing to "dodge", and anything bigger (like a building) you are unlikely to be able to dodge anyway.

It seems intuitively safer to stay inside the car (it's built in some ways to keep you safe), and it won't necessarily be hurt by the movement itself.

See tree falling almost on top of car - also, guy seemed to want to protect other people.

I read that it is safer to lie down alongside the car rather than be in it or under it. This is because the car won't mash down to be less than a foot thick and will support debris off you, whereas it doesn't have to crush much to kill you inside or under it.

I'm skeptical. Any recent US car has to be able to withstand at least 3X its weight, in order to make rollovers survivable. The amount of force the car's roof can withstand is much higher than how much my skull can withstand.

Surviving its weight says nothing as to how much of a dynamic impact it can withstand, and earthquake debris can fall from great heights.

A decent sized tree branch will do a lot of damage to a car’s roof. A wind storm knocked a tree branch off and onto my first car. Wasn’t pretty.

I was thinking the same and then thought, oh no, the car maybe is crushed under debris? Then when the smoke cleared I thought, phew, no, no damages to windshield - and then again - NO! - a tree across the street. Something like that could easily have crushed a car along with its occupant.

Here's the original tweet, instead of a retweet:

https://twitter.com/Excelsior/status/913961924181630976

That dude's black car rocking back and forth was interesting.

Park gear with no handbrake on, I would guess.

reading this I wondered two things:

    - will Elon Musk come up with an earthquake mode for autopilot
    - could you use kinetic oscillation to charge your battery

ps: if you align all cars along the wave's normal, and use regenerative breaking, would this absorb the quake ?

A magnitude 7 earthquake releases approximately 5 PJ over less than a minute, so let's say 100TW. A Tesla supercharger provides 120KW, so even if the braking system is equivalent, you'd need 1B cars.

> you'd need 1B cars.

Now there's an investor pitch I'd love to hear.

If y'all buy my 1B cars you get quake-free life and faster charge !

-- Salesman

Wow. I really thought there would be more energy in an earthquake. That's just like a smallish nuke.

What's the appropriate reaction in a situation like this ? Do you stay outside and risk falling trees, buildings and electrocution ? Or do you go inside the nearest building and find something to hide under ?

Stay outside. Try to find an area that has minimal falling objects. If possible, find something sturdy to shelter inside like a bus stop. Knell down to prevent yourself from losing your balance and be observant of your surroundings. Try to remain in place but move if you see the situation rapidly deteriorating like puffs of dust being spewed from concrete building columns.

https://www.ready.gov/earthquakes is probably going to be a better resource than anecdotes from mixed sources.

Any way to counter being electrocuted by overhanging wires in an earthquake?

Seems pretty hopeless

A chainmail suit will direct the energy around you. They make more pedestrian looking versions of these which folks who work with high voltage often wear as protection

Now I'm on a natural disaster video kick. Here's the tsunami in Japan.

https://www.youtube.com/watch?v=G_0rQ9hnP84

Incredible video. Apart from the conspiracy theory they snuck in at the end…

lmao, hadn't gotten to that part yet.

This video was taken at the intersection of Calle Amsterdan & Calle Laredo in the La Condesa neighborhood of CDMX: https://goo.gl/maps/21xm3yfo1Su

Here's a high resolution version of the video: https://www.youtube.com/watch?v=-jYOn3uvj_w

How will self driving cars handle this, or other fast moving emergencies such as a tornado? Is it hooked in to earthquake and weather monitoring systems and just shuts down or what?

I imagine when the telemetry is all way out of expected parameters, it could go into a safety mode.

It has to seem routine at first, especially down South in that area, but when the building falls, that must have been utterly terrifying.

Title should have a [video]

Right. But "camera" does the thing. I didn't expect an article or an image; video is what I expected to be at the end of the link.

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