Subtitle: How to think about earthquakes in a way that protects your mental health
A total of 3093 earthquakes with a magnitude of four or above have struck within 300 km (186 mi) of Ibaraki, Japan in the past 10 years. This comes down to a yearly average of 309 earthquakes per year, or 25 per month. On average an earthquake will hit near Ibaraki roughly [once a day].
Ibaraki Earthquake Statistics on the earthquakelist.org website
There is always the possibility of a big earthquake in Japan; however, certain areas (like southern Ibaraki where I live) seem to have a lot of little quakes where the epicenter is quite close, so it can be stressful getting jolted around on a regular basis if you don’t understand what is happening, and if you don’t have an “inner narrative” to talk to yourself about what is going on.
So, here is my advice.
In Japan, whenever an earthquake happens, you can get a report on the magnitude, location, and depth of the earthquake within a few minutes of it happening by checking the JMA website, watching NHK on TV, or listening to NHK Radio 1 (only in Japanese).
When you experience a quake that is big enough to bother you, find out the magnitude, location, and depth to help you process what is going on. Your goal is to find out whether it was big, or close, or shallow. It needs to be at least TWO of these in order to be dangerous.
Here is graphic to help you remember this, and I will explain below.
(Note that these are just categories that I made up to help make sense of earthquakes, so you won’t find them referenced elsewhere!)
When you hear about an earthquake happening on the news, it is likely because it is BIG. In Japan where the infrastructure is generally designed to withstand a certain amount of shaking, an earthquake would probably have to have a magnitude of around 6.0 or more to do the kind of damage that would start to significantly disrupt lives. Note that in some other countries, and in areas of Japan where homes and buildings are older and/or haven’t been brought up to code, smaller earthquakes can also cause more extensive damage. But an earthquake that is big, but not close to where you are, or not significantly shallow is less likely to affect you. So “bigness” alone is not a cause for panic.
In the vast majority of cases in southern Ibaraki, earthquakes that we experience are CLOSE but not particularly big or shallow, so they are type B. They come on strong and tend to wake you up or surprise you, but even though they are very close (sometimes coming within a few kilometers of my house), they are not big enough or shallow enough to do major damage. So, “closeness” alone is not cause for panic.
Earthquakes that are SHALLOW are more likely to do extensive damage. My experience over many years in Japan has taught me that a depth of around 50 km or less is getting into dangerous territory, and when you start seeing depths of 20 km or 10 km, you are definitely going to want to pay attention. But “shallowness” alone is not cause for panic.
So, say you experience an earthquake which was kind of bumpy, but nothing fell off your shelves.
- You look up the information about the earthquake and you find that it was CLOSE. However, if it was close to you and didn’t cause any damage, then it probably wasn’t big or shallow.
- Or somebody tells you that the earthquake that just happened was BIG, say a magnitude 7.0 quake. However, if it was that big and it didn’t cause any damage, then it probably wasn’t close or shallow.
So, when an earthquake happens and it feels very strong, try to remember that it could feel strong because:
| A | It is big, but not actually close or shallow. | You probably don’t have to worry about it because it’s not close to you. |
| B | It is close, but not actually big or shallow. | You probably don’t have to worry about it because it’s not big enough. |
| C | It is shallow, but not actually big or close. | You probably don’t have to worry about it because it’s not big enough or close enough. |
| D | It is BIG AND CLOSE and/or SHALLOW. | Only worry if two or three of these conditions are met. The good news is that it is pretty rare for all this to happen. |
Using the above categories can help you process what is happening so you don’t go to maximum red alert every time a quake happens. For example, in southern Ibaraki, we tend to get lots of As, Bs, and Cs so the vast majority of the time, you can experience the earthquake, look up the information, figure out whether or not two or three of these conditions have been met, and if not, resume your regular activities without going into panic mode.
Of course, this doesn’t mean that you shouldn’t take cover or take other measures to protect yourself when an earthquake happens. This “thinking framework” is meant to help you live comfortably and safely in an earthquake-prone zone, not to convince you to ignore it when an earthquake happens!
Also, please note that there is currently no way to predict whether or exactly when most earthquakes will happen. We only have the science at this point to tell us sometimes, with certain kinds of quakes, a few seconds in advance that a quake is coming.
So, to summarize, my advice is that when an earthquake happens, first find out the stats about it by checking the JMA website, watching NHK on TV, or listening to NHK Radio1 (only in Japanese), then decide whether it is an A, B, C, or D. If it is A, B, or C (just big, just close, or just shallow) you can go back to your daily business and stop worrying about it. If it is a D and you are fine, you can also go back to your daily business and stop worrying about it.
In other words, in the vast majority of cases, you do not need to freak out. If you do start to feel yourself freaking out, look up the stats about the earthquake to either set your mind at ease or give you more information about what you should do next (e.g. do nothing, help yourself, or help others).
In my 22 years in southern Ibaraki, and my 27 years in Japan, I have experienced only one earthquake that had enough of an impact to cause damage in my city. That was the Tohoku Earthquake in March 2011, which was one of the biggest earthquakes ever in recorded history, and therefore, a very rare event. That earthquake was VERY big (9.0) and quite shallow (24 km), but not close to me (about 300 km away), so it was a Type D (BIG+SHALLOW, not close).
I have never (touch wood) experienced any other Type D earthquakes that caused damage in my city.
That is not to say that one will not happen. It is just to say that there are lots of different kinds of categories of possible earthquakes, and knowing which one you experienced can help you mentally defend yourself from going to “Level 3000” every time an earthquake happens.
This may or may not work for you, but this is how I have managed to live happily in “bumpy Ibaraki” for as long as I have without letting the regular earthquakes give me cause for panic.
If you combine the above advice for protecting your mental health with the following advice for reviewing your emergency preparation plans, you should be able to live relatively happily here in Japan, despite the occasional rattling.
The following official government site gives you guidance on how to prepare three days’ worth of emergency supplies for households of various sizes and compositions based on your answers to a brief quiz.
I recommend checking out this link and thinking about how to prepare your household for an emergency such as a large earthquake, or flooding in the region, that might impact on getting supplies.
