#85 Disaster prevention II
A collection of useful tips for disaster preparedness before leaving for Japan.
Last week, we looked at significant earthquakes, particularly the Great Kanto Earthquake of 100 years ago, and considered how you can survive. As I wrote last week's post, I realized that much academic information about earthquakes in Japan is available in English. However, it can be difficult for those coming from countries that do not have earthquakes. To find out how we can obtain a minimum of knowledge in a limited amount of time and make it useful in an emergency, I checked various websites as sources of information that will help readers deepen their understanding quickly. I hope this information will help ease some of your worries.
Mechanism of Major Earthquakes in Japan
Japan is located in a "particularly earthquake-prone area" on the earth. The Japanese archipelago is found on top of a place where the plates that cover the earth collide, which causes earthquakes, so earthquakes are common. Although Japan covers only 0.3% of the world's land area, more than 20% of the world's six or more significant earthquakes occur in Japan. The map below shows how frequently earthquakes occur in and around Japan.
The Japan Meteorological Agency provides an obvious explanation of the mechanism of earthquake occurrence in Japan. It is only available in Japanese, but I would like you to use the translation function to help you understand.
Although a bit academic, the explanation by the Kobe University researcher is easy to understand from a different perspective.
So, with some understanding of these generalities, what kind of awareness should we, residents of the Tokyo metropolitan area and many travelers, have of the possibility of an earthquake directly below the Tokyo metro area?
In the case of the massive earthquake in Tokyo
The Tokyo Metropolitan Government has launched the "Tokyo Resilience Project" to protect the citizens of Tokyo from wind, flood, and earthquake damage, and its measures are widely published. The project claims a 70% probability of a massive magnitude seven or greater earthquake occurring within the next 30 years.
The project advocates that such a massive earthquake would result in collapsed houses, paralyzed transportation networks, and prolonged water and sewage outages. It would be no exaggeration to say that the situation would be life-threatening for travelers in Tokyo.
The Japan Times article also provides a more concrete statistical outlook on the severe effects of the concentration of people in Tokyo during a significant earthquake. Everything that underpins the human flow and logistical infrastructure is concentrated in Tokyo. If a substantial earthquake disrupts that flow, the city will ultimately lose its function as the capital of Japan.
As Japan's public broadcaster, NHK has made disaster reporting one of its missions. It has numerous online resources to protect lives, especially from earthquakes and typhoons. Please click here and translate for Metropolitan Earthquakes.
Nankai Trough Earthquakes
The Nankai Trough earthquake is an intensity seven or more significant quake over a wide area from the Tokai region to the Kinki, Shikoku, and Kyushu regions. Since these regions have a large population concentration and are critical areas for various industries, the economic damage and we expect human casualties to be enormous. Although some errors are based on past archives, they have occurred at intervals of 100 to 200 years, and the authorities expect them to happen with a reasonably high probability within 30 years.
For more information on the mechanism, please look at the detailed pamphlet on earthquakes published by the Japan Meteorological Agency. The following is a quote.
The Nankai Trough, which runs from Japan's Suruga Bay to the Hyuganada Sea region, is an oceanic trench where the Philippine Sea Plate subducts underneath the Eurasian plate (continental plate) at a rate of several centimeters a year. In some places, the two plates stick together, causing the lower plate to pull the upper one downward and creating an accumulation of strain. When this build-up exceeds the bearable limit, the upper plate snaps back, and a Nankai Trough Earthquake occurs. The Philippine Sea Plate continues to subside along the trough, and the cycle of pulling down and snapping back repeats.
The CG video produced by the Cabinet Office is straightforward, showing the mechanism of such a massive earthquake and the damage it could cause. This video demonstrates that the Nankai Trough earthquake will generate a tsunami much earlier than the Great East Japan Earthquake because the epicenter of the Nankai Trough earthquake is closer. The magnitude of the tsunami can be much more significant. Records indicate that even if the Nankai Trough earthquake subsides once, it may occur again, possibly in adjacent areas, in conjunction with another earthquake, leading to severe damage. The worst damage estimate is 320,000 victims, and economic damage is estimated to exceed 320 trillion yen.
Tsunami hazard maps for each area can be found on the following website. Please use the translation function, as there is no English version.
The Nankai Trough earthquake will have its epicenter on the southern coast of the Japanese archipelago close to the coast and may cause a tsunami much higher than that of the Great East Japan Earthquake. Some coastal areas are flat, and you must evacuate to higher ground before the tsunami. In Kochi Prefecture, all coastal cities, towns, and villages expect to experience tsunamis 10 meters or higher, with Tosashimizu City and Kuroshio Town expected to undergo a tsunami of 34 meters, the largest in Japan.
How to survive in a massive earthquake
NHK's Japanese website describes actions and keywords to save your life during an earthquake in Tokyo. Since there is no English version of the site, please use your browser's translation function to read it. In particular, the last section, "When and What Will Happen After the Disaster?" precisely describes what infrastructure will be out of service on the day of the disaster, the next day, and so on until one week later. Once a disaster strikes, transportation and communication infrastructure will be paralyzed, making it difficult to take necessary actions. Knowing what actions to take in such an environment is very important.
In the case of a Nankai Trough earthquake, on the other hand, it is essential to evacuate immediately. Due to the nature of this earthquake, residents in the area are likely to be forced to vacate for at least a week because of the wide range of magnitude 7-class earthquakes and the possibility of solid earthquakes occurring in areas far from the epicenter, such as the Shikoku region, followed by a strong earthquake in the Tokai region. The following video created by the government is dramatized and has English subtitles. Knowing how to act during a Nankai Trough earthquake should be helpful.
Essential apps
Based on the lessons learned from the Great East Japan Earthquake, if a tsunami warning is issued while staying in a coastal area, you must evacuate to higher ground immediately. For this purpose, it is advisable to have multiple disaster response applications. The following are just a few examples.
Safety Tips: Disaster information, such as earthquake information, is available in 14 languages under the supervision of the Japan Tourism Agency.
NHK World Japan: News and programs are available in 19 languages via the web and apps. It also broadcasts English news in a particular disaster section using an AI voice.
I’ve included for you below the government-issued apps and websites useful in times of disaster.
Although this week's post partially duplicates last week's post, I hope you will look at the WEB sites I have mentioned and realize that as long as you travel in Japan, the possibility of encountering a significant earthquake is inevitable. Please be sensitive to whether the places you visit are high-risk locations and gather information on earthquakes and other disasters. Please install several disaster apps before departure and turn on the notifications. By doing so, your trip should be much different. It may be a hassle, but please consider disaster preparedness indispensable to your trip to Japan.
I hope this post will not be too much concerning for you. We live here, and all the information is just for precaution. Have a safe trip, everyone.