Japan is notorious for earthquakes. It experiences thousands per year. We are all aware of the terrible devastation they can cause after the major quake of 11 March 2011. But what is it like to feel a quake for the first time or be in a country which is so prone to them? Well, here are the first impressions of one of the uninitiated, being me.
Before I moved to Japan, I was incredibly keen to feel a quake. I'd never felt one in my life apart from the time I strapped myself into an earthquake simulator in Nara. It wasn't long until I got my wish. It was all a bit of an anti-climax, though. Before I arrived, I had read of “major aftershocks” of magnitudes 6 and 7 striking Japan and “rocking buildings in Tokyo”. It was only after sitting through a few of these “major aftershocks” that I realised you barely notice them unless you are located in a building several levels up and sitting perfectly still.
The best aftershock I've felt so far was at 8.08 am (Japan Standard Time) on Tuesday, 12 April. I was lying in bed at the time in my 9th storey apartment. My room gently swayed for a few moments, there was a slight creaking sound and a book I had left teetering on the edge of my desk fell to the floor. That was it. I didn't feel any need to rush from the building. In fact, I didn't even feel the need to get out of bed. It was as if a strong gust of wind had rocked the building or a heavy truck had driven by outside.
After a minute or so I summoned up the motivation to get out of bed (it was not a work day) and logged on to the earthquake section of the Japanese Meteorological Agency website to check where the quake had occurred and its magnitude. As it turned out, a magnitude 6.3 quake had occurred about 200 km away from Tokyo at a depth of about 30 km. Its epicentre was at sea. In Tokyo, it was felt as a magnitude 4.0 quake.
I looked out my window. The workman on the scaffolding outside were still working, people were walking to work, cars were driving by … it was business as usual. In fact, all of these people probably wouldn't have even realised that a quake had occurred.
It wasn't long before the first foreign news reports of this quake emerged. Reuters were first to the punch. According to Reuters “another major aftershock [had] rocked eastern Japan, swaying buildings in central Tokyo”. Technically, Reuters were correct. A magnitude 6.3 quake is “major”; eastern Japan had “rocked” to some extent and yes, buildings swayed in Tokyo albeit slightly. However, the impression you would get from reading this report is that people had frozen in abject terror contemplating whether to evacuate from the swaying building or whether the very walls around them would crumble at any moment. Nothing could be further from the truth.
The previous day I had been shopping in IKEA when a magnitude 7.1 quake struck off Eastern Honshu, once again, about 200 km away from Tokyo. According to foreign news agencies, buildings in Tokyo were “rattled” by this “serious” aftershock. If I'd read about this quake back in Australia, I would have imagined items falling off shelves in IKEA and people fleeing the store in terror. A few people from home actually emailed me asking about the quake. So what did happen? Well, nothing actually. Myself and the other shoppers didn't even notice the quake as it was only felt as a magnitude 3.0 in Tokyo, we were on the ground level of IKEA and we were far too enthralled by what piece of chipboard furniture we could buy next.
The two quakes I've mentioned illustrate an important point which is rarely reported by foreign news agencies: The magnitude of the quake at its epicentre is not that important. What matters is the magnitude it is felt at where you live. As the epicentre may be hundreds of kilometres from a densely inhabited area, the magnitude it is felt at by people is often far less than what it was at its epicentre.
A useful indication of how a quake feels is given at the bottom of this post. Based on my limited experience, it seems pretty accurate. As you can see, it is not until a quake reaches magnitude 5.0 that you are likely to realise that a quake has actually occurred. The major earthquake of 11 March 2011 (which was originally reported as magnitude 7.9 by the Japan Meteorological Agency but later upgraded to magnitude 9.0) was apparently felt as a 5 magnitude quake in Tokyo. In other words, you know it is quake but there is very little damage. In the regions closest to the epicentre, it was in the 6s. As we know, it was the tsunami which caused the catastrophic damage more than the quake itself. Take a look at the link at the bottom of this post from the Japanese Meteorological Agency which gives you some useful data on how the 11 March 2011 quake was felt across Japan.
So next time you read about a “major aftershock” in Japan, visit the Japan Meteorological Agency website and check the magnitude it was felt at in Tokyo, Osaka, Nagoya or another heavily populated area. If it was not felt as at least magnitude 5.0, assume that no-one noticed it and if they did, they probably didn't care.
Take care
Our Man in Japan
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The earthquake section of the Japan Meteorological Agency website
The Japan Meteorological Agency report on the earthquake of 11 March 2011
How earthquakes of different magnitudes feel
9.0 and above — Causes complete devastation and large-scale loss of life.
8.0 — Very few buildings stay up. Bridges fall down. Underground pipes burst. Railroad rails bend. Large rocks move. Smaller objects are tossed into the air. Some objects are swallowed up by the earth.
7.0 — It is hard to keep your balance. The ground cracks. Roads shake. Weak buildings fall down. Other buildings are badly damaged.
6.0 — Pictures can fall off walls. Furniture moves. In some buildings, walls may crack.
5.0 — If you are in a car, it may rock. Glasses and dishes may rattle. Windows may break.
4.0 — Buildings shake a little. It feels like a truck is passing by your house.
3.0 — You may notice this quake if you are sitting still, or upstairs in a house. A hanging object, like a model airplane, may swing.
2.0 — Trees sway. Small ponds ripple. Doors swing slowly. But you can't tell that an earthquake is to blame.
1.0 — Earthquakes this small happen below ground. You can't feel them.
(Source: www.scholastic.com)
Thanks for explaining this, going by reports from the media here, you'd be forgiven for thinking that Japanese is on the verge of being swallowed up by Poseidon.
ReplyDeleteVery interesting Pete. I'm keen to know about how the nuclear fall out is playing out in Japan. How are people in Tokyo reacting? What are people eating? The impression here is that all fish and fresh food is out of bounds and people are forced to eat imported canned food. Give us the real story!
ReplyDeleteHi, Eviltravels. So far I've been here just over a week. Everyone seems cheerful and relaxed from what I can see. The weather is nice, the cherry blossoms are out and the parks are packed with picnicers on a Sunday afternoon.
ReplyDeleteI have been eating and drinking anything on sale. I was speaking with two people yesterday who had just come back from eating fresh fish at the Tokyo fish market and they seemed to have no issues.
The supermarkets are stocked with fresh produce and I see people buying it.
I haven't been specifically asking people what they are eating but I can imagine some people may be steering clear of fish for now out of an abundance of caution.
That's all I can really say for now as I have only been here a short period. I can only speak from my own observations. Hope that helps you.