Live data from Hacker News

Strong earthquake hits northern Japan, tsunami warning issued

www3.nhk.or.jp

81–90 of 168 posts

Re: Strong earthquake hits northern Japan, tsunami warning issued

#81

This would be the tenth major earthquake (7+ magnitude) along the Pacific ring of fire this year. With the Kamchatka and other earthquakes in the news recently I had a fear that were building to some major event but turns out that this year is about average if not slightly below average for major quakes along the ring of fire.

It's probably related to a phenomenon we're not yet aware of.

It's probably not.

Re: Strong earthquake hits northern Japan, tsunami warning issued

#82

This would be the tenth major earthquake (7+ magnitude) along the Pacific ring of fire this year. With the Kamchatka and other earthquakes in the news recently I had a fear that were building to some major event but turns out that this year is about average if not slightly below average for major quakes along the ring of fire.

I heard that smaller (relative) earthquakes actually lower the prob of larger ones, so maybe it is a good thing? A bunch of 7.X earthquakes in the ocean are not going to be hugely destructive.

On the one hand earthquakes remove tension from the earth’s crust and release energy that can’t be used in future shocks.

On the other hand, if a shock doesn’t release all energy it may come to rest in a relatively weak spot that will soon give away again (https://en.wikipedia.org/wiki/Earthquake_swarm: “The Matsushiro swarm lasted from 1965 to 1967 and generated about 1 million earthquakes. This swarm had the peculiarity of being sited just under a seismological observatory installed in 1947 in a decommissioned military tunnel. It began in August 1965 with three earthquakes too weak to be felt, but three months later, a hundred earthquakes could be felt daily. On 17 April 1966, the observatory counted 6,780 earthquakes, with 585 of them having a magnitude great enough to be felt, which means that an earthquake could be felt, on average, every two and a half minutes.”)

Because of that, I think an earthquake will increase the probability of one occurring again soon, but decrease its strength.

Re: Strong earthquake hits northern Japan, tsunami warning issued

#83
post #80

Earlier quoted context omitted.

What's a Naruto shadow clone? Google hits are just about a kids show.

That is the reference

The Wikipedia redirect is apparently dead (https://en.wikipedia.org/?title=Shadow_clone&redirect=no) and the main page for Naruto doesn't show anything about shadow clones.

Care to explain the reference? Do people dress up like a character from the TV show and help out people or what's going on?

Re: Strong earthquake hits northern Japan, tsunami warning issued

#84
post #65
post #58

Today I got served this video " Earthquake and Liquefaction his Urayasu, Chiba 3/11/2011 " [0], which is from the earthquake which caused the huge tsunami in Japan. I have rarely seen something as scary as this. [0] https://www.youtube.com/watch?v=FGblnPeOXJg

The flood videos of towns, cars, and people being violently washed away are way scarier IMO. Urayasu looks built on the water and all I see in the linked video is a threshold condition where the water is just barely peeking up through the ground below. People are still walking around, cars driving. There are far more chaotic and destructive scenes on youtube from that tsunami.

Different kinds of scary. The tsunami is clearly more dangerous as an actual threat, but it basically looks and works like a flood. This is a pretty familiar threat.

We think the ground is familiar too. So watching it change into something else, a squirming alien beast, is a different kind of fear. It violates your assumptions about what is safe, about what is possible at all.

Re: Strong earthquake hits northern Japan, tsunami warning issued

#85

When I was in japan the earthquakes were oddly exciting rather than scary, had three different ones while I was there that visibly shook rather heavy objects around. Two being in a building and one outside. It was rather interesting seeing things shift around leaving a permanent imprint that there was in-fact an earthquake and it wasn't some kind of illusion when earthquakes these size couple of decades ago would cau…

I lived in California for a while. I’ve always found earthquakes exciting. Probably because I trust the building codes and the ones I experienced were pretty mild.

Re: Strong earthquake hits northern Japan, tsunami warning issued

#86

Earlier quoted context omitted.

Your comment prompted me to go read about epicenters and I learned something new. The hypocenter of an earthquake is apparently the point of origin of the earthquake and the epicenter is the point on the earth's surface directly above the hypocenter. Had never heard of a hypocenter before.

I didn't know about hypocenter before too but it's neat how you can sometimes deduce the meaning of a word from its parts (because "hypo" means "under"/"below" in Greek, like in hypodermic, hypoglycaemia, etc).

Basically every language works that way? You can say underquake in English if you like, doesn't have to be Greek. In fact, it might make sense to pick a widely understood language rather than one with ~13 million speakers

Re: Strong earthquake hits northern Japan, tsunami warning issued

#87
post #58

Today I got served this video " Earthquake and Liquefaction his Urayasu, Chiba 3/11/2011 " [0], which is from the earthquake which caused the huge tsunami in Japan. I have rarely seen something as scary as this. [0] https://www.youtube.com/watch?v=FGblnPeOXJg

Terrifying. I know that Japan is earthquake-proofing its architecture but how about the underground infra? Do they have to dig and redo the pipes? The cables seem to be mostly overground (at least in this video) and are probably easier to repair (oldschool infra ftw).

Re: Strong earthquake hits northern Japan, tsunami warning issued

#88

Earlier quoted context omitted.

https://www.geo.ruhr-uni-bochum.de/en/new-study-connects-ear...

https://news.caloes.ca.gov/earthquake-myths-separating-fact-... Myth 5 is "Small Earthquakes Relieve Pressure and Prevent Larger Ones"

GP is correct; I'm not sure why CA gov is calling that a myth (it's not). However keep in mind that it's not necessarily true 100% of the time. Or at least the things it might seem to imply at first glance aren't true - the presence or absence of small quakes in a given period doesn't necessarily tell you anything useful about the future.

Re: Strong earthquake hits northern Japan, tsunami warning issued

#90

Somewhat offtopic curiosity: Is there anything that Japanese fishkeepers do to keep the water and livestock inside the tank during earthquakes? Here we have no such risk for earthquakes, so a 600lb tank of water 4ft off the ground isn't much of an issue, even when bumped. I'd imagine earthquakes of this frequency could complicate that.

I have a 60L fish tank in my Tokyo apartment on around the 10th floor. It's sitting on stand that is not bolted to the wall. I have several friends with similar setups.

In the last 6 years there have been two or three earthquakes that caused enough water to slosh on to the floor.

Of those only the 2021 Fukushima earthquake caused any fish to slosh out - perhaps 10 medaka if I recall correctly. Luckily I was home and I was able to save all the fish, however there was one adult red cherry shrimp that didn't make it because I had trouble picking it up off the floor. I cleaned up the water with some paper towels and it didn't seem to cause any lasting damage.

I think if I had a 600 lb (270L?) tank or expensive fish though I would probably have a different perspective.

Post reply on HN