Facts and Fiction: Earthquakes and Tsunamis in Japan

Coming from South Africa, where we have minimal earthquakes and tsunamis, I often get concerned phone calls and messages from friends and family whenever a Japanese earthquake manages to make international news. In fact, I’ve often been warned about the dangers of Japan and how I should stay away from there (ironic as the Japanese feel the same way about the dangers of South Africa).

But after the earthquake this morning, and the subsequent tsunami warning, I’ve decided to make a list of earthquake and tsunami facts and fiction. Hopefully, this will help people understand the realities of these natural disasters.


If you’re coming to Japan and want to know what to do in the event of an earthquake or a tsunami, then check out this post here.


1. The Pacific Ring of Fire

The entire island of Japan is located right on top of The Pacific Ring of Fire – an area around the Pacific Ocean where 75% of the world’s volcanoes are located. This infamous ‘ring’ also touches on other notable areas such as New Zealand, California, and Chile.

And although the Ring of Fire is mainly described as an area of oceanic trenches, volcanic arcs, and volcanic belts, earthquakes and seismic activities are also a main characteristics of this area. In fact, 90% of all earthquakes occur in this horseshoe-shaped zone.


2.  1,500 earthquakes happen yearly

Yes, it’s true. Over 1,500 earthquakes are recorded every year – with magnitudes ranging from 4 to 7 in strength. And earth tremors happen daily all around the country. Earthquakes with readings above 7 (unlike the 6.9 earthquake this morning) are slightly more rare, but still happen fairly regularly with over 10 of these earthquakes being recorded since the infamous 2011 Tohoku earthquake. (That’s more earthquakes than all the tremors that have occurred in SA since the 6.3 of 1969).

In fact, earthquakes and earth tremors are so common in Japan that people barely even react unless they’re in the epicenter of a 6 magnitude earthquake or higher. That’s right, most Japanese people will just continue on with their day – slightly annoyed at any inconvenience that an earth tremor might cause.


3. Japan has 10% of the world’s active volcanoes

Another scary aspect about Japan is the sheer number of volcanoes that they have in the country. And as we all know, volcanoes can be far more dangerous as they can not only cause earthquakes, but also cast the area around them into darkness and death. And, incredibly, Japan hosts over 100 active volcanoes – more than any other country.

In fact, the most famous volcano is that of Mt Fuji, the very symbol of Japan itself:


4. Japan is listed 17th on the 2015 World Risk Report

According this report, Japan is the 17th most dangerous country in terms of natural disasters. This is out of 171 countries (where South Africa ranks as 105). And despite the fact that this assessment takes into account Japan’s readiness to withstand natural disasters, it is still the highest ranked developed country in the world.


5. 2011 Tohoku earthquake was the most powerful to hit Japan

At a whopping 9.1 magnitude, the 2011 Tohoku earthquake was the biggest to strike Japan in recorded history. (With the second biggest being 8.6 in 1707) The quake hit at about 2 in the afternoon, but thanks to the stringent seismic building codes and early warning systems, many deaths and injuries were prevented.

However, as the earthquake struck offshore, a destructive tsunami was triggered. The tsunami waves are said to have reached run-up heights of 39 meters at Miyako city and reached as far as 10 km inland in Sendai. Overall, the flooding is said to have covered an approximate area of 561 square kilometers in Japan.

A report released by Japan’s National Police Agency in 2015 confirmed that there were officially 15,894 deaths, 2,557 people missing, and 6,152 people injured. And according to the Japanese government, the total cost of the damages caused by the tsunami has reached about 25 trillion yen (3.2 trillion rand).

But if you want to find out more about the Tohoku earthquake, then click here.



Now that we’ve got the grim facts out of the way, lets look at some of the myths surrounding earthquakes and tsunamis in Japan.

1. Most of the damage is caused by high-magnitude earthquakes

Magnitude is not the main determining factor of the damage done by an earthquake. In fact, damage and severity of resulting effects are caused by an intricate combination of magnitude, the distance from the epicenter, and the local geological and structural conditions. For example, an earthquake in farm land is far less damaging than an earthquake in central Tokyo.

And even this direct damage from the earthquake might not be the worst. Instead, the resulting effects, such as tsunamis, fires, floods, and landslides, can cause way more damage and have further reaching consequences. Indeed, the reason why the 1923 Kanto earthquake was so destructive was due to the fires that broke out across the area.

2. Tsunamis are 100 ft tall

In action movies, such as 2012 and The Day After Tomorrow, tsunamis are shown to be hundreds of feet tall, to topple skyscrapers, and to completely wipe out countries. This has caused many misconceptions about the definitions of tsunamis, with people thinking that they have to be at least 100 ft (30 meters) tall to be considered one. However, the official definition looks a little different:

Tsunami /tsuːˈnɑːmi/ n. a long, high sea wave caused by an earthquake or other disturbance.

As you can see, no height requirement. In fact, the tsunami this morning only reached about 4.5 feet (1.4 meters) at it’s peak. And while this height is by no means good, it’s far less than what people imagine when they hear the word ‘tsunami’.


3. The 2011 Tohoku Quake was the most deadly

While the 2011 earthquake was the strongest one to hit Japan in recorded history, the quake that really caused the most damage was the 1923 Great Kanto Earthquake. The death toll reached approximately 140,000 and with about 2 million people left homeless in the resulting aftermath.

However, just like the 2011 earthquake, it was not the quake itself that caused the most destruction. It was, in fact, the resulting fires and coincidental typhoon that caused panic, destruction, and desolation in the Kanto area of Japan.


If you want to find out more about this destructive earthquake, click here.

4. An earthquake is a single explosion

When I first came to Japan, I had no idea what to expect from my first earthquake experience. But from what I gathered from movies and such, I figured that it would be like a sudden shake accompanied by a loud boom. Kind of like a bomb. But what really happened surprised me.

Much like the quake this morning, earthquakes tend to have more of a shaking quality to them with little accompanying sound. And even though I have never experienced being in the epicenter of a particularly powerful tremor, I know that earthquakes tend to last anywhere from between a few seconds to a few minutes – definitely not the instant explosion I expected.


5. The whole of Japan is affected

Okay, this one is not entirely false. Of course many areas are affected by earthquakes and if you check out this article, you will see just how far-reaching the 2011 earthquake was.

But the myth part of this entry is due to the fact that many foreigners think that Japan will be swallowed whole when an earthquake strikes any area of the 378,000 km² island. Indeed, I’ve been personally asked by friends and family if I felt the 2016 Kumamoto earthquakes near Kyushu, which is over 1,000 km away. And even though I felt touched by my friends who contacted me this morning, I feel embarrassed to admit that I, in fact, slept through the entire thing!


Now, while earthquakes (and the damage they incur) are nothing to laugh at, it is important to know that sometimes Western media over-exaggerates the impact that earthquakes have in areas like Japan.

And while Japanese media might also sound a bit stern and serious about many high-magnitude earthquakes, this is only to ensure the safety of all citizens. Remember, many lives were lost in 2011 quake, and Japanese warning systems are now in place to point out the seriousness of all earthquakes in order to encourage people to evacuate rather than think “Oh, this isn’t as bad as 2011, let me just chill in my bed”.

So, if you have a friend in Japan when you hear about a dangerous earthquake:

  1. Stop.
  2. Check the reports.
  3. Check where your friend is living.
  4. Contact them.

This could help prevent any panicked reactions from friends and family, as well as the spread of any misinformation and sensationalism.


2 thoughts on “Facts and Fiction: Earthquakes and Tsunamis in Japan

  1. Pingback: In the Event of an Earthquake… – Booth in Japan

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