M5.6 quake rocks central Japan

Why does Japan use a completely different scale from the Rest of the world?

So, the image shows that nearly 2/3 of Honshu were effected by this quake. Please tell me again how they judge some areas to be safe for nuclear power plants because they are not on an active fault. The whole flipping country is an active fault! Glad there were no serious injuries, but it just shows how fickle Japan's earthquake management is. Did the early warning alerts trip? Unlikely!

We barely noticed it here in Hachioji

After a series of large quakes, NZ also started announcing intensity scales. It really makes a lot of sense. Using magnitude alone can't adequately convey how bad it was in specific locations. You'll notice that even at similar distances the intensity is different in different locations.

Crickey: it doesn't follow a different scale, but reports both magnitude and seismic frequency, etc. besides, I'd trust Japan on this one more than nations that rarely suffer the same devastation and rate of quakes, tsunamis, and so on.

I felt this one in Osaka. Lasted a good while in terms of rocking.

Why does Japan use a completely different scale from the Rest of the world?

There are two types of seismic scales, those measuring magnitude and those measuring intensity at various locations. Japan uses the same magnitude scale as most places (see the M5.6 reading in the diagram). There are various intensity scales in use around the world, and no "common" scale. Japan's uniqueness may be in its large number of monitoring stations that allow intensity to be measured over the entire country. The diagram above shows how useful this can be in getting a picture of the effect of the earthquake.

My girl jumped up with a start saying earthquake while sleeping this am and I laughed at her. Laughed at her again this morning recalling it till I read this.

Usually I can see my fish tanks sloshing a bit if there's a quake, but they were calm, so I thought she was having night terrors :)

The Japanese Shindo scale totally makes sense. In that it gives a clue to subjective movement and its possible effects. It makes sense as a supplement to simple Richter scale magnitude measurements. Relative depth and rock types are also factors which can mean a lower magnitude quake having a higher Shindo and vica versa. Also helps explain why there can sometimes be more extensive damage further from the epicenter.

way different than the silly calendar nonsense.

I was also completely insensible to the earthquake this morning in northern part of Tokyo. For some reason, I have been unaware of earthquake these days. I think I'd better brace myself for the big one.

Well we were driving at that time of day - didn't feel a thing !

This must have shaken Mt Fuji.

Had one in the early a.m here as well which got my attention. Everyone got an emergency bad to hand? Oh these days small portable water filters are available for next to nothing, better than packing lots of bottles imo.

Quick question. How often should we change the emergency bottled water?

nandakandamandaToday  07:13 pm JST

"Quick question. How often should we change the emergency bottled water?"

Not knowing what type you have prepared I wouldn't be able to answer that question. I suggest you check the best by or expiry dates on the bottles.

nadakandamanda: "How often should we change the emergency bottled water?"

Why type of bottle is it? If it's your average PET bottle of water I'd change it every half year, or definitely at the end of summer. It'd still be drinkable, I'd think, but it's not wise to consume things that have been heated in plastic, especially over a long period of time, as chemicals can leech into the water. I think if it's part of an emergency kit they can last a lot longer.

What they fail to mention is that this quake was followed by 20+ additional ones, right underneath Mt. Ontake. Makes one wonder if something bigger is in the works.

nandakamanada - check the best before date on the bottles. Get into a habit of having extra supplies of food you regularly eat (curry, ramen, breakfast cereal in our house) as emergency rations, and each time you buy new supplies, put them in the emergency supplies and take out the ones with the closest expiry date and put them in the general supplies. Easy habit to get into and will reduce your reliance on outside supplies when the big one happens.

Unable to reply individually to all the good and helpful answers above, but thanks guys n gals. I like the rolling ideas.

Japan uses different scale than countries that hardly experience earthquakes.

I was mostly suprised that the huge rocks were fallen. I think that it is dangerous to live near the sea or mountain in Japan, such as Tsunami, landslip.. There is no telling where or when an earthquake will happen next. Actually, my hometown is located in Kyushu prefecture. When the earthquake was occured there, my friend and family had a tough time without any preparation, so i realize that i should prepare for the earthquake which i was about to forget.

This must have shaken Mt Fuji.

More likely Mt. Ontake which can be seen from the Kiso River valley.

I think that a lot of Japanese people forget about how terrible the earthquakes are. What will happen if the next giant earthquakes happen in Tokyo? Japan will definitely be deeply affected by it. For instance, failure of power and water supply and the economy in Japan. We can't do anything to prevent earthquakes, but we can prepare and be ready for an earthquake event. I believe that all of us must never forget how terrible the effects of earthquakes are. We should think about early preparations and anticipations for any kind of earthquake. No matter how strong it may be, it will still affect us.

Better get those Power plants up and running before they are too damaged to restart.

@Kodai. it is widely expected that a M9+ will hit tokyo in the near future. there is also a fear that Fujisan might erupt closed rail and volcanic dust closing airports.

if you can trust scientists and emergency planners they predict 330,000 deaths and one million buildings damaged. their plan consists of closing all highways in Tokyo for the sole use of emergency vehicles. that would mean its vital to have at least a weeks supply, including water for hygiene.

Thought I felt my apartmentbuilding shake when I looked outside nobody seemed worried.

@Goodlucktoyou,

All good advice, but as someone who was living & working in Koriyama when the 2011 magnitude 9 quake hit, my experience is that you need at least 3 weeks worth of food & water.

The supply chain failed into Koriyama, with warped roads and rail lines, so gasoline stations couldn't get resupplied, and neither could supermarkets, for the first 3 weeks.

Gasoline was rationed in Koriyama for about 4 weeks after the quake - getting up at 3am in order to queue up at the local garage at 4am in order to get a voucher for returning back to the garage for 1500 Yen's worth of fuel later that afternoon wasn't a pleasant experience, but was necessary - so if at all possible, and I realise that not everyone can do so especially if they live in flats in Tokyo (I had a detached house in Koriyama), having a few Jerry cans worth of fuel stored in a safe place and treating the fuel with fuel preserver and implementing a fuel rotation system (use up the oldest fuel and refresh it after 6 months or so of storage, put the next oldest fuel next in the 'refresh queue') is a good idea if you have a car.

Have a generator handy - amazing how much you realise you need electricity in those times - in which case keeping a store of fuel is also necessary as above. I had a generator, but we were very lucky in our part of Koriyama because our electricity supply kept working - dunno how, I kept quipping that our supply equipment was made from Unobtanium at the time. Same for our water supply, it somehow was fine as well - I guess living quite close to the Miharu water dam might have had something to do with it.

Have one of those table top cartridge gas cookers, with a store of gas cartridges as well - serves as a backup method of heating food and boiling water in case you have no means of electricity supply.

And lastly, try to come up with a workable bug-out route or routes. When Fukushima Dai-ichi (which was about 33 miles from my house) went FOOM!, I immediately ensured that we had a full tank of gasoline in our little Wagon R by siphoning off the fuel from the big Honda Orthia we also had (which is why I mentioned keeping a fuel store above - that one caught me out big time), and kept that car on standy so we could bail out if required.

Obviously, even doing all of that above won't guarantee you won't somehow get caught out by circumstances around you, but at least you have tried to mitigate some of the effects of a disaster.