Has Japan done enough to Mitigate against Tsunamis?

JAPAN FINALLY got “THE BIG ONE”

By Kevin Stoda

For years, Japan has been awaiting “the Big One”. Well, that event has arrived. On the one hand, there has been a lot of devastation and too much loss of human life. On the other hand, where good housing and earthquake resistant building technologies were developed, those regions did rather well, i.e. considering that Japan was hit by both an 8.9 (Richter Scale) Quake followed by a massive tsunami and hundreds of aftershocks all along Honshu’s northeast coast.

http://news.yahoo.com/s/yblog_theenvoy/20110311/ts_yblog_theenvoy/watch-raw-footage-of-the-japan-earthquake-and-tsunami

So far, the great Sendai Earthquake of 2011 has left over 250,000 people living in temporary shelters. There have already been over 1300 official deaths—and many more peoples missing or not accounted-for across the northeastern Japanese prefectures of Miyagi and Fukushima. International rescue efforts are under way.

http://www.worldnewsco.com/4254/earthquake-tsunami-1000-people-killed-215-thousand-japanese-citizens-refugee-camps/

When I lived and worked in Japan in the early 1990s, I lived in Itoigawa City, which gives its name to the most infamous dividing line on Honshu, the largest island of the Japan archipelago. That fault line is called the Itoigawa-Shizuoka Tectonic Line (ISTL). A lot of research in preparation for a “Big One” have centered upon this point where the Asian and North American tectonic plates come together.

http://adsabs.harvard.edu/abs/2009AGUFM.S51B1401I

It is not clear, at this point, whether the earthquake off of Sendai City, however, is directly or more indirectly related to the shifts and pressure on and around the ISTL.

Japan has certainly suffered great numbers of damaging earthquakes historically. For example, the Great Kanto Earthquake of 1923 led to over 100,000 deaths in the Tokyo region alone. Incidentally, some 30 million people currently live in that same Kanto region. It is claimed, however, that modern earthquake-resistant structure will protect these inhabitants better than the flimsier structures of by-gone generations.

http://en.wikipedia.org/wiki/Lists_of_earthquakes

It is, therefore, important to recognize that the Haiti Earthquake of January 2010, with a 7.0 score on the Richter scale, killed more people and destroyed a greater percentage of that society’s structures than the Sendai Earthquake has.

In short, construction practices in any country make a difference in the post-earthquake survival rate, but they do not stop tsunamis nor impede them very much, especially when the tsunamis hit ten meters in height for a hundred or more kilometers along any particular coast—as was the case with the Sendai Quake for Northeast Honshu.

“A report published by the United Nations Environment Programme (UNEP) suggests that the tsunami of 26th December 2004 caused less damage in the areas where natural barriers were present, such as mangroves, coral reefs or coastal vegetation. A Japanese study of this tsunami in Sri Lanka used satellite imagery modelling to establish the parameters of coastal resistance as a function of different types of trees.”

http://en.wikipedia.org/wiki/Tsunami

This means that if Asian countries continue to reclaim land from the sea in their ocean side construction projects, as Japan does, they need to do so while respecting the other ecologically sound demands of our more natural ecosystem. For example, contractors also need to develop or create (and maintain where possible) natural barriers, such as coral reefs and mangroves.

Historically, Japan has done poorly in working with nature along its many coastlines. The most common feature of protection too often has been cement and rebar solutions. Japan has to learn to work with nature in building up more reefs and mangroves along its coasts.