How To Solve Japan’s “Tsunami Problem”?

Ryan Nelson

Living with disasters has become synonymous with living in Japan. From earthquakes and tsunamis to typhoons and nuclear bombs and meltdowns, the media portrays Japan as a place always on the brink of chaos. Some of this coverage is hype and speculation, but how can Japan prepare for when a large disaster actually does affect Japan, such as the devastating earthquake and tsunami on March 11th, 2011? Japan is located on the Ring of Fire, an extremely seismically active plate boundary that surrounds the Pacific Ocean. Throughout Japan’s long struggle with seismic activity, tsunamis have devastated the coasts of the country and caused catastrophic disasters. However, tsunamis are very hard to predict, even with modern science. Sometimes it is decades between truly destructive tsunamis, but when they do hit, their destruction is unparalleled to other types of natural disasters in Japan.  Preventing loss of life and mitigatI got damage has been century long challenges for modern Japan. From sea walls, to evacuation warning systems to 3D modeling and depopulation or areas at risk, the methods of solving the “tsunami problem” holds inherent social issues that make planning for disaster a complex problem. This page will focus on what the government and local communities have done to try to solve the problem, what the future may hold for tsunami preparedness, and how the coastal societies are affected by the measures and precautions. It will seek to answer the questions of how Japan has prevented damage of large tsunamis and warned of their danger, what proposals for the future might work, whether the public supports their potential inconveniences, and why preparing for tsunamis is a more involved issue than it may seem.

Japan is one of the most seismically active countries on earth. Around 15,000 earthquakes are measured each year on the islands of Japan. When earthquakes occur below the ocean, the disruption of land as it moves on the tectonic plate can move vast amounts of water. This movement creates the phenomena of a tsunami: a tidal wave capable of massive destruction of homes, businesses, and life in coastal communities and cities. Tsunamis have affected Japan for centuries, but modern disaster history and precautionary measures only goes back about two centuries. In The Great Meiji Sanriku Tsunami of 1896, 22,000 lives were claimed.1 The maximum height of the tsunami was 38.2m at Ryori in Sanriku Iwate Prefecture 2 It was after that disaster that Japanese scientists began to seriously study why tsunamis happened in a methodical process. The Council on Earthquake Disaster Prevention (CEDP) had been created just five years earlier under the Department of Education. The original thought had been that the tsunami had been caused by an earthquake, but this notion was hotly debated because of the weakness of ground shaking that had been felt. However, by looking at the tide records, they managed to determine that a wave of this length could only be caused by large fault motion. 3

Sanriku Coast

By 1933, after another large tsunami, the Showa Great Sanriku Tsunami, reaching 29m at its maximum height, hit the same Sanriku region (see figure 1) comprehensive countermeasures were officially introduced. They proposed the following countermeasures in a system that aimed to act a new guide to preparation and policy for tsunami disasters (translated from Japanese by the US National Library of Medicine National Institutes of Health):

  • Relocation of dwelling houses to high ground: This is the best measure against tsunami.
  • Coastal dikes: Dikes against tsunamis may become too large, and financially impractical.
  • Tsunami control forests: Vegetation may damp the power of tsunamis.
  • Seawalls: These could be effective for smaller tsunamis.
  • Tsunami-resistant areas: If the tsunami height is not so high in a busy quarter, solid concrete buildings are to be built in the front line of the area.
  • Buffer zone: Dammed by structures, a tsunami inevitably increases its height. In order to receive the flooding thus amplified, rivers and lowlands are to be designated as buffer zone to be sacrificed.
  • Evacuation routes: Roads to safe high ground are required for every village.
  • Tsunami watch: Because it takes 20 minutes for a tsunami to arrive at the Sanriku coast, we may detect an approaching tsunami and prepare for it.
  • Tsunami evacuation: The aged, children and weak should be evacuated to safe higher ground where they could wait for about one hour. Ships more than a few hundred meters offshore, should move farther offshore.
  • Memorial Events: Holding memorial services, erecting monuments, etc. may help keep events alive in people’s mind.4″

This comprehensive list of disaster mitigation would act as a framework for the central Japanese government. Along with a tsunami warning organization that was founded on the Sanriku coast and then enacted in 1952 as the Meteorological Business Act to cover the entire Japanese coast, this was Japan’s line of defense to prevent the death toll and loss of life seen in the previous two major tsunamis.5

An obvious answer looms after a tsunami tears through a town or city. The tsunami is a wall of water so blocking it with a wall or dyke of more dense material (concrete or earth) should prevent the water from entering into the area and causing damage. This method of prevention, outlined in CEDP’s plan, was implemented swiftly following their conference. In 1950, “Shore protection works were started and were legally authorized under the Seashore Act enacted in 1956” 6 These embankments were meant to protect from both storm surge from typhoons as well as tsunamis. After the Ise Bay typhoon of 1959, the embankments were soon found to be unhelpful even under a storm surge of 3.9m, a full 25m short of the highest peak of the 1933 tsunami. The embankments, “made with soil with solid covers only on the seaside surface were completely washed away by overflowing seawater.” 7 The design standard was revised for embankments for all three surfaces to be armored with concrete. However, the protection still was not enough. In 1960, a tsunami was caused by a massive earthquake in Chile and travelled across the Pacific Ocean. The earthquake, the most powerful to date on earth at a 9.5 on the moment magnitude scale occurred 570km south of Santiago, Chile, but triggered a tsunami that crossed the entire Pacific Ocean, causing damage in Hawaii, Japan, the Philippines, New Zealand, Australia, and Alaska.8 After the damage caused by the Chile tsunami, the government doubled their efforts into the creation of the concrete armored embankments and seawalls. In 1968, the Tokachi-Oki Earthquake and Tsunami that hit the Hokkaido and Sanriku regions tested the system again. The tsunami height was lower than the seawalls and embankments, and they held well. The wall system was treated as a success, though it was possible for a mega-tsunami to crest the top of the walls.9

The disaster prevention model came into question again in 1993 after the Hokkaido Nansei-Oki Earthquake and Tsunami hit Japan on July 12th. The top of the seawalls on the affected Okushiri Island was 4.5m above sea level, while the tsunami peaked at over 11m. This reflected a serious failure in planning and building the seawalls. In 1997, a new proposal by the National Land Agency and six other government organizations, entitles “A Guidance on Reinforcement of Tsunami Disaster Prevention Countermeasures in Local Disaster Prevention Planning” sought to make up for these failures in the future. As hinted at in the title, the publication dealt partially with how to reinforce sea walls and embankments. They discussed how to base precautions on a hypothetical tsunami. “One candidate,” that they offered, “ is the largest past tsunami from which credible materials can be obtained, and the other is the possible tsunami caused by the largest earthquake that can be supposed to occur based on present knowledge and science.” 10 However, the reinforcements were not enough in some cases. Even in 2011, seawall improvements failed to save many communities. Many of the seawalls were detrimental to the areas they were protecting when they were overrun and broke. The resulting pressure build up of the wave behind the wall can act like a rubber-band effect with the release causing the water to inundate the area with more force than if the wall was never there. Secondly, they revised the three components of the CEDP 1933 plan, defense structure, tsunami-resistant town development and evacuation based on warning, to more accurately fit a modern society and modern technological and scientific capabilities. Note that this revision took more than 50 years.

Since then, the Japanese government  has continued a trend of devoted resources to expanding sea wall infrastructure as the main component of tsunami damage prevention. Today over 56 percent of Honshu’s coastline, Japan’s main island, is fully or partially artificial.11 Strong and tall sea walls can be very helpful, especially in industrial areas such as the Fukushima Nuclear Plant, where a sea wall existed but was compromised and destroyed by the wave in 2001. However, after the national Government took initiative after the 2011 tsunami to create what the media dubbed “The Great Wall of Japan”:  a 440 wall project in the prefectures of Fukushima, Iwate, and Miyagi, there was disapproval from local citizens. Building these walls requires the approval of each locality and there has been opposition to encasing communities in “concrete fortresses”. One of the opposers of a wall in his village is Masahito Abe, a resident and schoolteacher in Koizumi in the Miyagi prefecture. He was upset with government plans stating, “we want the government to change the shape of the coast, and redesign it so a tsunami would have minimal impact, not just build walls.”12 A local assembly member already saw the debate as, “weakening the determination to rebuild their village together”. Despite that, Abe noted that much of the town seemed to prescribe to a stoic idea of acceptance of government decision with, “the attitude [seeming] to be that if the walls have already been planned and budgeted for, why interfere?” The idea that the government knows best is reflected by the system in which relief aid is brought to communities. In Japan, the national government tasks local administrators and governments to the implementation public works projects. However, the system is not always cut and dry. “Regional politics and economies have become overly reliant on public works construction” 13 and cities will jump on any opportunity for construction possible as a way to bolster an economy in recession. However, ultimate decisions about projects are left to the prefectural and national governments. If towns and cities want supplementary funding from these bodies, which is readily available to compliant projects, they must stick to the set out parameters. The national government, overloaded with projects, often can prefer a “cookie-cutter” approach to simplify complex projects. As an example, Rikuzentakata in the Iwate Prefecture, “lost 55% of its tax revenue after the earthquake, but its budget for the year increased six times thanks to relief funds for reconstruction provided by the central government”14  (more on this project later). The national government is right to point to places like Fudai village, where, “a 15 meter wall that was dismissed as a waste of money when it was built…in the 1980’s” saved the town, but refuses to take into account areas like Kamaishi, where the largest sea wall in the world at the time was smashed through by waves and offered little resistance. Sea walls, for all of the space, resources and division of coastal communities from the ocean, are not proven to succeed at rates that many would deem them to be economically or socially feasible. Abe points out that, “I don’t want the rest of the world to think of Japan as a concrete fortress. The tsunami was a force of nature, so I can forgive it…but for humans to ruin their own environment…I can never forgive that.”15 Building sea wall is an easy and visible way for the Japanese government to show progress for tsunami damage mitigation and to show their citizens that they can be held accountable for doing something, but the thought and planning put into the building of the walls may not be enough for such a (meant to be) permanent solution. Japan, before anything, is a set of islands and its society is very connected, economically and socially, to the sea.

When the sea walls broke and inundated communities after the 3/11 disaster local governments and communities wanted answers, and more importantly solutions. One such answer of tsunami prevention came from far in Japans past. Media outlets around Japan and the world started picking up the story of ‘tsunami stones’: stone tablets that had been found on hillsides that marked the level that tsunamis had reached hundred and even thousands of years in the past. Itoko Hitara, a specialist in the history of natural disaster at Ritsumeikan University in Kyoto described the stones as, “ warnings across generations, telling descendants to avoid the same suffering of their ancestors…The flat stones, some as tall as 10 feet, are a common sight along Japan’s northeastern shore” 17    as reported by the New York Times, following the March 3rd 2011 tsunami. Some of the stones carry messages like “Don’t build your home below this point” while others warn to “ drop everything and seek higher ground after a strong earthquake”. Around Japan, a country rooted heavily in its respect for its past and ancestors, an idea that by ignoring their relatives warning in stone they did not prepare well enough for disaster was popular. Fumio Yamashita, an amateur historian in the Iwate Prefecture agreed with the sentiment stating, “As time passes, people inevitably forget, until another tsunami comes that kills 10,000 more people.”17



Fig. 2

Some Japanese have tsunami stones to thank for the safety of their homes and lives: in Aneyoshi, a tsunami stone states, “ high dwellings ensure the peace and happiness of our descendants.” See Figure 2. The town obeyed the warning and even painted a blue line of a road downhill from it; the farthest the tsunami reached in the 2011 disaster. Some stones were not as helpful though: they were swept away by the wave that was the largest Japan had seen since 869 A.D..18 The tsunami stones may have helped some communities, but they did not act as a full system of protection for the Japanese coastline. A villager in Aneyoshi who lost his grandchildren when they swept away in low-lying areas summed up the stones, by explaining that, “we are proud of following our ancestors, but our tsunami stones can’t save us from everything”19 The Japanese can be nostalgic for a “better” past, but there is only so much to learn from the sporadic inscriptions.

So, if not only an increase in sea walls, infrastructure, and looking to the past for lessons on tsunami survival what can be done? After the 3/11 disaster many ideas have been proposed to prepare for the next big tsunami. Though, as stated above, it is the governments plan to invest in the “Wall of Japan” sea wall restructuring, there are many other contributing bodies that have alternative plans for disaster mitigation, but no perfect solution. Two years after the 3/11 disaster, in 2013, a group of scientists at the Seismological and Volcanological Department of Japan’s Meteorological Research Institute (MRI) (Now the Seismology and Tsunami Research Department) 20 devised a new warning system for tsunamis that they say could have saved hundreds of lives. Through the use of GPS buoys and Ocean bottom pressure gauges, the MRI was able to assess the magnitude of offshore tsunamis. After plugging in the data retrospectively from the March 11th tsunami, they found results that “suggest the method could have provided tsunami information with a lead time of more than 5 minutes for tsunami with heights of 5-10m on the Sanriku coast.” 21  See Figure 3.


Fig. 3

This could be a significant improvement from past systems, but still does not leave much time for evacuation. Even with a perfect evacuation plan, the physical damage to a town or city is unaffected. Takeshi Koizumi, a senior coordinator for international earthquake and tsunami information at the MRI told the Telegraph, “I think it is true that Japan has the world’s highest quality systems in relation to issuing near shore tsunami warnings. This is not because of our hardware or software, but because of Japan’s experience” 22 He notes the improvements they learned that they needed after the 3/11 disaster naming, “Before, we had batteries that only lasted three or four hours but the blackouts on March 11th lasted for a day- so one by one our seismic stations died on that day. Our new battery system will mean they can last for three days in case of a huge earthquake” 23 With the new system, they expect that warnings will be more precise and issued more quickly. “About 40 per cent of near shore tsunamis hit the Japanese coastline in 20 min after the earthquake.” Koizumi explained. “In some cases, it is less than five minutes. Three minutes is our target response time to issue warnings to the public” 24 Two minutes warning still may not be enough time for many people to get to safe ground, but it is an improvement.

In Rikuzentakata, the local government is taking a proactive approach to preparing for the next major tsunami. The town, one of the hardest hit in the event, was almost completely swept clean by the wave. It had a coastal forest; one of the points on the CEDP’s tsunami preparation plan, but all but one tree was washed away by the huge surge of water. Now, Rikuzentakata has a radical, yet expensive, plan to save the city from both tsunamis and the economic obstructions of a sea wall: literally raise the land the city is built on. Amya Miller, special advisor to the City of Rikuzentakata explained in a Skype call to the Disaster Archipelago: Japan class that the plan was to, “literally move mountains” 25 from across the river to raise the level of the former downtown area. New city ordinances forbid residential homes to be built on this newly formed land, but with the raised area, hopefully businesses and industries can utilize the land with less fear of their property being damaged by a future tsunami. The idea is revolutionary, but still holds the issue of the displacement of thousands of families. To solve this issue, the city is building cheap, modern apartment buildings higher up in elevation and basically shifting downtown back up into the base of the hills. The project still is very risky and holds a very high price tag. Even still, the growing elderly population puts Rikuzentakata and many other cities at risk of disappearance. Towns, especially those with newly added seawalls are losing the economic benefit of their area. Along with the overall push for urbanization in Japan this means the tsunami may have been the last string broken for many young Japanese looking for lucrative employment to go elsewhere. The government has and can look into ways of keeping people in the areas, but from a purely statistical standpoint, the lack of population could be a benefit if another super-disaster hits the area. Less people to care for and fewer structures could put less of a strain on the Japanese economy and, in a way, save lives. However, this is hard to come to terms with for many Japanese who see the northern coast of Honshu, the area the tsunami did most of its damage, as a idealistic and rural representation of a Japanese life that rarely exists anymore, especially in places like Tokyo.

Matsushima Bay, an area whose small island are considered to be one of Japan’s scenic treasures and a major tourist destination, was spared while nearby cities were devastated. This occurrence has to do with the many rock islands that dot the bay which, “over the ages, the deep-blue waves… have sculpted…into fantastical shapes, on top of which grow miniature forests of pine trees.” 26 The islands are more than ascetically pleasing though; they acted to break up the tsunami wave as it entered into the bay. A boat captain from the area, Sai’ichi Aizawa explained that, “If you go south you see Tagajo and Arahama, and if you go north you see East Matsushima. All of them were demolished by the tsunami. But because of these islands we were saved.” Now, the area is trying to take lessons from nature and apply them there and elsewhere. Artificial barrier islands could be one of several solutions for areas along the craggily Sanriku coast to minimize the strength of tsunamis before they hit land.

Various other towns and cities have alternative ideas to solving tsunami damage mitigation, but they are typically not able to implement them. This is not due to a lack of willpower or corruption per say, but rather a combination of the overwork of local officials and a model in which it is much easier to accept national government money and plans than it is to create locally devised ones though open forums. It has become the norm to call “’explaination sessions’ where no substantial exchange of opinions is carried out…Even if individual residents have dissenting ideas, it is hard to give them momentum” 27 The heads of these committees can often be respected elders, but their views often reflect other elders views and leave out younger citizens opinions. Many of the younger residents find it easier to move to more urban areas rather than fight the process to be heard. There is a prevailing message in Japan from the government posing the projects as “respect for human life”. This is a justification for, “sea walls, embankments, shifting residents to higher elevations; plans that allow no leeway for questions.”28 However, some residents feel they will be unable to live normal or economically productive lives because of the projects, reconstruction, and relocation with unsuitable temporary living and that all of it will take away from their livelihood more than save lives.

Science in predicting and warning of tsunamis will continue to improve in the future, but as seen above, preventing damage is a much tougher task. One possible solution, found by researchers at Harvard University, suggests that instead of reinforcing structures, water should be allowed to flow strait through them. “Instead of trying to obstruct the wave, you allow the wave to pass through the structure while causing minimal [structural] damage,” Said Dr. Gopal Madabhushi of Cambridge University on the research when interviewed by the BBC. By designing houses and buildings this way, “the goal is to protect the building and make it easier to reconstruct afterwards, on the assumption that the occupants have fled to higher ground”29 However, “for your average residential structure, it’s down to the owner as to whether they’re going to put these preparations in place” warned Dr. Adrian Chandler, an earthquake engineer at UCL’s Hazard Research Center. The full integration of this system would be impossible and even if building standards changed, not enough structures could be built or retrofitted before the next big tsunami will probably hit. However, in conjunction with other ideas it could be part of a safer future for Japan’s coastline.30

There is no single answer to Japan’s “tsunami problem” yet. As apparent from the 1896, 1933, 1960,1993 and 2011 tsunamis, there is much to learn about new methods on how to evacuate quicker and mitigate damage and they must be continually revised over time. As well, cooperation between the local and national governments and full citizen participation in the rebuilding and planning of disaster communities is necessary in ensuring that the right measures are implemented. Otherwise, the social and economic implications of structures and policies put in place can negatively affect communities consistently in trade for protection from events that only happen every few decades. Having a “respect for human life” is very important, but so is a “respect for human quality of life”. If Japan wants to preserve its coastline communities and keep its citizens safe at the same time, a balance must be found.



Works Cited

1. Shuto, Nobuo, and Koji Fujima. “A Short History of Tsunami Research and          Countermeasures in Japan.” Proceedings of the Japan Academy. Series B, Physical and Biological Sciences 85.8 (2009): 267–275. PMC. Web. 16 Apr. 2015.

2. “The Meiji Sanriku Earthquake (June 15, 1896, M 8 1/2) and Sanriku Earthquake (March 3, 1933, M 8.1).” Hp1039. Jishin.Go.JP, n.d. Web. 08 May 2015. <>.

3. Shuto, Nobuo, and Koji Fujima. “A Short History of Tsunami Research and Countermeasures in Japan.” Proceedings of the Japan Academy. Series B, Physical and Biological Sciences 85.8 (2009): 267–275. PMC. Web. 16 Apr. 2015.

4. Ibid.

5. Ibid.

6. Ibid.

7. Ibid.

8. “1960 Valdivia Earthquake or Great Chilean Earthquake.” The Most Destructive Tsunamis. SMS Tsunami Warning, n.d. Web. 08 May 2015. <>.

9. Ibid.

10. Ibid.

11. “In Post-Tsunami Japan, A Push To Rebuild Coast in Concrete.” E360 Gallery. Yale University, 16 May 2013. Web. 08 May 2015. <>.

12. McCurry, Justin. “Tsunami-proof ‘Great Wall of Japan’ Divides Villagers.” Theguardian. The Guardian, 29 June 2014. Web. 15 Apr. 2015.  <>.

13. Ibid

14. Oguma Eiji, “Nobody Dies in a Ghost Town: Path Dependence in Japan’s 3.11 Disaster and Reconstruction,” The Asia-Pacific Journal, Vol.11, Issue 44, No. 1, November 4, 2013.

15. Ibid.

16. Fackler, Martin. “Tsunami Warnings, Written in Stone.” The New York Times. The New   York Times, 20 Apr. 2011. Web. 15 Apr. 2015. <>.

17. Ibid

18. Ibid

19. Ibid

20. “Research on Advanced Tsunami Forecasting Methods | Meteorological Research Institute.” Meteorological Research Institute (MRI) | JMA. Meteorological Research Institute (MRI), 2003. Web. 08 May 2015. <>.

21. Demetriou, Danielle. “Tsunami Two Years On: Japan Finally Gets Warning System That Would Have Saved Hundreds of Lives.” The Telegraph. Telegraph Media Group, 9 Mar. 2013. Web. 15 Apr. 2015.  < lives.html>.

22. Ibid.

23. Ibid.

24. Ibid.

25. Miller, Amya. “Rikuzentakata in 2015 Talk with Disaster Archipelago: Japan.” Skype, Hartford/Rikuzentakata. 3 Apr. 2015. Lecture.

26. Burnett, John. “Tsunami Spares Japan’s Pine-Covered Islands.” NPR. NPR, 18 Apr. 2011. Web. 08 May 2015. <>.

27. Oguma Eiji, “Nobody Dies in a Ghost Town: Path Dependence in Japan’s 3.11 Disaster and Reconstruction,” The Asia-Pacific Journal, Vol.11, Issue 44, No. 1, November 4, 2013.

28. Ibid.

29. “Japan Earthquake: Can You Tsunami-proof a Country?” BBC News. British Broadcasting Corporation, 11 Mar. 2011. Web. 08 May 2015. <>.

30. Ibid.

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