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Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

earthquake.usgs.gov

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Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#31

Post by topbanana »

ablation wrote: post #17
mrb wrote: post #2

Really cool "green lightning" effect observed before and during the earthquake: https://mobile.twitter.com/AlanEchelon96/status/906031454529... I believe this phenomenon is still not understood...

Earthquake lights like other posters have said, but I wonder if the exceptional geomagnetic activity caused by the recent X-level CME event has any sort of impact on this too? (Thinking auroral activity, but at far too low of a latitude of course).

I received an email aurora alert late last night UK time, so perhaps there was increased solar activity?

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#32

Post by bhrgunatha »

saagarjha wrote: post #25
seanmcdirmid wrote: post #13

Earlier quoted context omitted.

Each point release just about doubles the force of the earth quake. Makes me wonder how my mom handled the Good Friday one in Anchorage, which was at 9.2.

Actually, it takes around 0.3 to double to power.

USGS (and most reports use the moment magnitude scale - https://en.wikipedia.org/wiki/Moment_magnitude_scale :

Each point is 10 ^ 1.5 (about 31)

Every 2 points is 100

The Richter scale is almost never used now but that'd where the factor of 10 per point comes from.

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#34

Post by Nition »

FooHentai wrote: post #30
adventured wrote: post #3

Earlier quoted context omitted.

It's from damage to the electrical grid.

This explanation is posted whenever earthquake lights are reported, but it's wrong. I have a few reasons: First. So the explanation goes, during the earthquake power substation transformers and fuses blow, causing these lights. Problem is, the grid doesn't sustain that level of damage during these earthquakes. Yes, the power usually goes out and there is grid damage, but the amount of damage is nowhere near 'every su…

There were a couple of good videos of the Earthquake Lights from that quake too. This one is really good: https://www.youtube.com/watch?v=BVVm7g3QgOA

The look is very similar to the videos of the ones in Mexico, and very different to the long-lasting beam of light from the ground that seems to come from generator explosions.

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#35

Post by hanniabu »

iaskwhy wrote: post #28
bamboozled wrote: post #18

Earlier quoted context omitted.

That's a really bad joke.

Actually earthquake quick release cycles are very good for humans as it prevents bigger earthquakes in the future. Same with volcanoes.

Yeah, and the longer the time between releases the more likely things are to break

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#36

Post by FooHentai »

Nition wrote: post #34
FooHentai wrote: post #30

Earlier quoted context omitted.

This explanation is posted whenever earthquake lights are reported, but it's wrong. I have a few reasons: First. So the explanation goes, during the earthquake power substation transformers and fuses blow, causing these lights. Problem is, the grid doesn't sustain that level of damage during these earthquakes. Yes, the power usually goes out and there is grid damage, but the amount of damage is nowhere near 'every su…

There were a couple of good videos of the Earthquake Lights from that quake too. This one is really good: https://www.youtube.com/watch?v=BVVm7g3QgOA The look is very similar to the videos of the ones in Mexico, and very different to the long-lasting beam of light from the ground that seems to come from generator explosions.

Amusingly that same video seems to be getting posted as being Mexico, too.

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#37

Post by perlpimp »

mrb wrote: post #2

Really cool "green lightning" effect observed before and during the earthquake: https://mobile.twitter.com/AlanEchelon96/status/906031454529... I believe this phenomenon is still not understood...

actually this is because of arcing beween swinging powerlines.

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#38

Post by kalleboo »

perlpimp wrote: post #37
mrb wrote: post #2

Really cool "green lightning" effect observed before and during the earthquake: https://mobile.twitter.com/AlanEchelon96/status/906031454529... I believe this phenomenon is still not understood...

actually this is because of arcing beween swinging powerlines.

Wouldn't it happen during strong wind as well in that case?

Re: Magnitude-8+ Earthquake, 87km SW of Pijijiapan, Mexico

#39

Post by kalleboo »

seanmcdirmid wrote: post #13
legostormtroopr wrote: post #10

Earlier quoted context omitted.

I appreciate those kinds of quick release cycles. I'm hoping that when they upgrade to 9.0 we get some new features though.

Each point release just about doubles the force of the earth quake. Makes me wonder how my mom handled the Good Friday one in Anchorage, which was at 9.2.

Magnitude is a pretty useless scale for the human-level impact of an earthquake (since you have to take into account location, depth, geography etc).

I prefer the Shindo scale in Japan, which better informs you how people actually felt it/it affected infrastructure. Each earthquake doesn't get "one" shindo scale, you get a map of shindo readings for each location it was felt in. Then you can say "this earthquake was up to shindo X" if you want to tell somehow the worst effects of it, or "at my house it was shindo X-2" and people understand "oh so you were pretty far away huh"

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