10 years after the Tohoku Tsunami

Published: 03/11/2021


A massive disater in Japan turned into a political debate. The Mw9.1 Tohoku earthquake and the following tsunami left 18,000 casualties and millions of people homeless. The following nuclear accident in Fukushima shook the world. Many questions are still open.

A massive disater in Japan turned into a political debate. The Mw9.1 Tohoku earthquake and the following tsunami left 18,000 casualties and millions of people homeless. The following nuclear accident in Fukushima shook the world. Many are asking now: How dangerous is nuclear power? How vulnerable are nuclear power plants? What should the world and what should Japan learn from the nuclear disaster? Questions that completely ignore the most important element.

Why was the tsunami so devastating? Why did no one of those responsible anticipate such an extent in advance? What are the lessons to be learned from this? What has Japan done since 2011 to improve preparation for such an exceptional event? What does this almost completely unexpected disaster mean for the rest of the world? Where do we stop preparation because it seems too unlikely? Why are people often mocked when they point out the dangers of worst case disasters?

Ten years ago, most people did not expect such a strong earthquake offshore Japan. Today, we know better. There and in many other regions, assumptions for the largest possible earthquake have been "raised" thanks to important fundamental research. But it has not yet reached most of the people. Today, we assume that we know where such strong earthquakes could occur: Japan, Indonesia, Alaska, Cascadia, Mexico, Ecuador, Peru, Chile, maybe Taiwan, maybe the Philippines, maybe New Zealand, but maybe we are also missing something.

However, magnitude 9 should not be the threshold for disaster preparation. Most of the catastrophic earthquakes, some with subsequent tsunamis, were significantly smaller. Even magnitudes of 6 to 7 can have similarly fatal effects if they happen in the wrong place and at the wrong time. There are various examples of "moderate" catastrophic earthquakes. Since 1960: Bam (Iran), Agadir (Morocco), Spitak (Armenia), Managua (Nicaragua), Latur (India), Yogyakarta (Indonesia). Agadir, magnitude 5.9, with 15,000 deaths is an extreme example. Earthquakes of this strength could happen almost anywhere. A potential disaster if you do not expect such an event.

Earthquakes which exceed worst case estimates at a place are not very rare. There have been a several examples lately: In 2021 alone Guyana, Guinea and Gambia, previously Botswana or the Ural Mountains. All of them are mostly unpopulated areas. There is no disaster without people. Even the strongest earthquake or the strongest hurricane cannot cause a disaster if no people are around. However, if such an earthquake, as in Guyana or the Ural (magnitude 5.7 - 5.9), hits a large city in a developing country, a small to medium-sized disaster would be inevitable. If a magnitude 6.8 was to happen, as it completely surprisingly happened a few years ago in the steppe of Botswana, in the centre of a major European city, let's name Cologne, Karlsruhe or Basel as realistic examples, we could probably add them to the list above.

The main lesson from the Tohoku earthquake should be to reduce harm from the unexpected. First, you have to identify the worst case. That's what Risklayer is doing. Whether this knowledge is in implemented in political action is another question. It is a long way with paths which are constantly being reformed by new scientific discoveries. But everyone could benefit from it in the end.

In the end, questions will remain: Were all actions sufficient? Was the assessment correct? Has the worst been prevented? You will only see something like that in retrospect. Or not. It will also not be possible to prevent every disaster. But each saved life counts. Japan repeatedly shows how to learn from disasters. The rest of the world should appreciate it especially today and foster it as inspiration. For 10 years, there has not been an earthquake / tsunami with more than 10,000 fatalities. Pure luck. The next one is sure to come. And a country, a region can learn from the upcoming disasters and review the mistakes of past and present.

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