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The struggle to understand why earthquakes happen in America's heartland

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Re: The struggle to understand why earthquakes happen in America's heartland

#21

Post by mjhay »

b112 wrote: post #9

There are earthquakes on the Canadian shield, and the reasoning is that it is due to Earth deformation recovery. Essentially, the ice age's massive glaciers deformed the ground, and it is slowly rebounding over 1000s of years. The result is minor tremors, sometimes larger quakes. I am in southern Quebec, and there is a LOT of water here. Personally, I suspect there are glaciers underground which are still thawing, wh…

There's not underground glaciers. Glaciers are always on the surface, and flow due to gravity. You're thinking of permafrost (which can form wedges and lenses of pure ice). Deeper permafrost responds slowly, but on the flip side of that, there never would have been deep permafrost in S. Quebec during the last glacial maximum. The permafrost situation also wouldn't affect isostatic rebound much, because the amount of water in the ground wouldn't change appreciably.

A rule of thumb is that only the first two meters of ground responds appreciably to annual variability, which also means that only the very near surface temperatures have the possibility of affecting snowmelt. Thus, any remaining deep permafrost would have almost no effect. It's too much of an insulating overcoat to allow for meaningful heat flux on those timescales.

Re: The struggle to understand why earthquakes happen in America's heartland

#22

Post by blincoln »

com2kid wrote: post #4
jmward01 wrote: post #3

What does it take to convince people to take risks like this seriously? The challenge is that hypothetical risks 'sometime in the next 50+ years' don't convince people to do things, at least in the US. The pacific northwest is at a much higher risk from an array of faults (not just the cascadia subduction zone) and volcanic hazards but even there, where the risks are very well understood, getting a large region to ta…

Building codes require earthquake strapping and take landslide risk into account. What more do you want people to do? Seattle has had large earthquakes in its short history as a large American city and honestly even mid 20th century construction held up ok. This isn't like parts of Japan where large earthquakes will happen on regular intervals. Engineers have to weigh costs vs risks.

> Building codes require earthquake strapping and take landslide risk into account.

"In Tennessee, jurisdictions can decide whether to opt in to building codes with earthquake provisions, while other states — like Missouri — don’t have state-wide building codes at all, though there are efforts to change that."

Re: The struggle to understand why earthquakes happen in America's heartland

#23

Post by losvedir »

lenerdenator wrote: post #16

> In Tennessee, jurisdictions can decide whether to opt in to building codes with earthquake provisions, while other states — like Missouri — don’t have state-wide building codes at all, though there are efforts to change that. I live on the other side of the state from New Madrid and can tell you, there's a 0% chance the Missouri state legislature passes a bill requiring earthquake proofing of buildings. You'd have…

I lived for a couple years in New Madrid county (pro tip for anyone reading: it's pronounced with the stress on the first syllable with an "a" like apple, btw), and I think this is right.

But the people are also not entirely wrong: it's dreadfully poor, so adding extra cost to buildings for something that might happen in the next 50 years is a tough sell.

I think people safe and sound and wealthy in California aren't really familiar with the perspective I saw there. It's like, what's the worst that can happen? You die? Tragedy and death are kind of expected and built in. People are generally very religious, a good number of people are in the military or at least have absorbed the idea that it's valorous to die for an ideal, and besides that are poor and don't really have health insurance and are accustomed to the the lingering idea of dying somewhat young.

Before we even talk about building code for earthquakes, let's remember that a whole bunch of people are living in trailers or double-wides in a relatively active tornado zone! One of my wife's colleagues died in a tornado while we were there and it was scary and horrible. And there are no basements because the water table is so high, so even moderately sturdier construction like our apartment is still honestly a little dicey. Several times my wife and I were huddled in our bathroom wearing bicycle helmets and a mattress draped over us with the tornado sirens sounding.

Nature is scary and ultimately it feels like there's just limits to what poor Southeastern Missouri can afford to do about it.

Re: The struggle to understand why earthquakes happen in America's heartland

#24

Post by s1artibartfast »

cloudwalk9 wrote: post #18
lupusreal wrote: post #11

Earlier quoted context omitted.

Bridge maintenance is sorely needed across the whole country. Anyway, the reason this stuff doesn't get enough funding is because the process of sorting out public spending priorities is called politics. Everybody has their own idea about what needs money and how much money should be thrown around. There's no objectively correct way to sort it all out, no means by which we can weigh the relative merits of increased l…

> Bridge maintenance is sorely needed across the whole country. Not just that, but also to rethink how we reinforce them in major waterways or even minor but navigable waterways, if any heavy enough boat can just crash into a support column and take the whole thing down... albeit accidentally in that case.

That is almost as unrealistic as wanting to nuclear bomb proof them

Re: The struggle to understand why earthquakes happen in America's heartland

#26

Post by s1artibartfast »

coding123 wrote: post #5
jmward01 wrote: post #3

What does it take to convince people to take risks like this seriously? The challenge is that hypothetical risks 'sometime in the next 50+ years' don't convince people to do things, at least in the US. The pacific northwest is at a much higher risk from an array of faults (not just the cascadia subduction zone) and volcanic hazards but even there, where the risks are very well understood, getting a large region to ta…

Most people don't want to live afraid of everything. I learned that lesson in the past 3 years.

I would add that everyone dies eventually.

Attempts to entirely de-risk life are a futile effort, and reasonable people can disagree on what level of safety is appropriate.

Re: The struggle to understand why earthquakes happen in America's heartland

#27

Post by jajko »

lenerdenator wrote: post #20
throwaway173738 wrote: post #19

Earlier quoted context omitted.

So you can see how a living wage and parity for tipped professions is actually in the national interest.

Exactly. The problem is, you will have to take money from some parts of the country to subsidize places like the Missouri Bootheel if you wish to see these sorts of improvements made, at least for a few decades. The engine for economic growth simply isn't there. Kansas City and St. Louis make up somewhere between 75-90% of the state gross product. Springfield and Columbia make up a little bit of the difference. The e…

... and thats communism in eyes of many, I'd say most americans (better redistribution of wealth instead of winners take it all and screw the rest, they didn't try hard enough). Healthcare is the same topic. So is public education.

Re: The struggle to understand why earthquakes happen in America's heartland

#29

Post by kbolino »

throwaway173738 wrote: post #19
lenerdenator wrote: post #17

Earlier quoted context omitted.

It's like everything else: it comes down to money. People who don't have much of it (which is to say, most of the area in the New Madrid seismic zone) don't want to spend it on something that might happen at some completely unpredictable time in the future. They don't want the government telling them to do it, either, because in their minds, that's the government telling them to spend money they don't have. More mone…

So you can see how a living wage and parity for tipped professions is actually in the national interest.

Unless such measures are applied globally (and practical space travel remains unobtainable), or a country completely isolates itself economically, these geographically bounded measures just displace the externalities.

Re: The struggle to understand why earthquakes happen in America's heartland

#30

Post by NoMoreNicksLeft »

jmward01 wrote: post #3

What does it take to convince people to take risks like this seriously? The challenge is that hypothetical risks 'sometime in the next 50+ years' don't convince people to do things, at least in the US. The pacific northwest is at a much higher risk from an array of faults (not just the cascadia subduction zone) and volcanic hazards but even there, where the risks are very well understood, getting a large region to ta…

> What does it take to convince people to take risks like this seriously?

What risks should a human in the 21st century take seriously? Like, if there is a 1-in-50,000 chance of death or lasting injury, is that something that should have me hiding in the closet? I'd take a 1-in-100 chance very seriously of course, I run into 1-in-100 events many times in any given year. If I am supposed to take a particular risk seriously, how much am I expected to pay to mitigate it?

You're slandering their ability to be rational without even taking into the account that they have evaluated it and judged the probability too low to act on without bothering to check if they quantify that correctly. They don't have the wrong numbers, they just set the threshold higher than you do.

For me personally, anything below about 1-in-5000 warrants very minor attention, anything in the 1-in-100,000 area isn't even worth thinking about. Covid was scary as shit, early on in some regions it seemed to rise above 1-in-2000 chance of death.

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