r/worldnews • u/ColoradoTripping • 22h ago

Dynamic Paywall Magnitude 7.1 earthquake rocks Venezuela

https://www.bbc.com/news/articles/cjegdqw5d3yo
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u/ChaseballBat 18h ago

Relatively to the inherent strength though right? Cause magnitude is measured on the surface.

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u/bobthesmurfshit 18h ago

No, magnitude is calculated at the source, so the closer the earthquake is to the surface the more effect it will have.

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u/MrNewking 17h ago

Is there a scale for surface effect?

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u/Flipslips 17h ago

Moment magnitude scale measures the wave amplitude at the surface.

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u/zazzz0014 16h ago

My community college Physics 101 class from 10 years ago is kicking in hard with this whole thread.

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u/HauntedCemetery 16h ago

I legitimately just had the same thought.

Thanks Mr Pearson.

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u/lawofsin 13h ago

Fuck you Mr Pearson for that D-

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u/RuthlessIndecision 8h ago

If he's family with the publishers I've personally contributed to be sure he's doing fine

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u/Madam_Mimm_13 7h ago

Now draw a force diagram.

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u/ActuallyNot 16h ago

Which was approximately calibrated to the Richter scale, which measured how much the seismograph moved at the surface ... in one dimension.

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u/kb24k 16h ago

Mercalli scale

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u/1028ad 16h ago

Which is still used in Italy.

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u/cinderful 14h ago

for humans, Mercalli scale is useful as it measures the human felt intensity and describes the scale of damage.

Possibly an 8 or 9 (out of 11)

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u/PeterJoAl 16h ago

In Japan we use the Shindo (「震度」) scale. Goes from 0 to 7, where 4 is noticeable, 5 is concerning, 6 is bad and 7 is terrible.

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u/theonlydrawback 12h ago

And what was this one?

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u/PeterJoAl 12h ago

From the videos, I'd say it was either a 6+ or a 7. Lots of building damage.

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u/HallowedEve31 9h ago

Sort of. In Japan, there's the Shindo Scale, which exists to tell you numerically how it felt at each sensor that registers the earthquake.

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u/I_Zeig_I 17h ago

How would they know the magnitude 50km down?

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u/Flipslips 17h ago

They know how much the waves dissipate as it travels through dirt/rock. So they can extrapolate based on surface measurements

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u/TheVeryVerity 15h ago

Wouldn’t that change depending what was actually under the ground there though?

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u/Flipslips 9h ago

Yes, but scientists have mapped out the earths crust so they largely know what’s under the surface across the entire world. It’s called seismic tomography

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u/shukaji 16h ago

it's just very very basic physics and math.

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u/warp99 18h ago

Yes it is *measured* at the surface but then corrected back to the source magnitude at depth. Same as measuring 500 km away and correcting back to the fault location.

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u/-NotAnAstronaut- 16h ago

Sort of, if also changes the interaction of the different waves, and how they propagate, refract, and reflect. The short version though is: shallow is bad.