Earthquake disasters have occurred frequently in recent years, and Japan has gained international recognition for its strong crisis management and prevention capabilities, and actively shares its earthquake disaster prevention experience and technology with organizations in other countries. Among them is Taiwan, which belongs to the boundary of the same seismic plate, and the two countries interact with each other to promote the improvement of overall earthquake disaster prevention and mitigation capabilities. I think we in Taiwan are already familiar with information about earthquakes in our own country, but what kind of seismic plates do we have in Japan? Where is Japan’s fault zone? What is the difference between earthquake disaster prevention measures and Taiwan? You’re not sure, are you? Let’s take a look together!
Earthquakes in Japan
Japan is located in the east of the Asian continent and northwest of the Pacific Ocean, located between four plates: the Eurasian Continental Plate, the North American Plate, the Pacific Plate and the Philippine Plate. Its unique geographical location makes Japan’s volcanoes and Japan’s seismic activity frequent. Large and small earthquakes have occurred many times in various parts of Japan since ancient times. In addition to the dangers of earthquakes themselves, tsunamis and volcanic activity caused by earthquakes pose serious life threats to residents and have aroused widespread concern in the international community. Therefore, this article introduces knowledge about earthquakes in Japan and introduces what kind of earthquake-resistant measures Japan currently has!
Before we begin, I will briefly introduce the famous earthquake events that have occurred in various parts of Japan over the past 30 years.
Earthquake in Japan: Great Hanshin Earthquake
The Great Hanshin Earthquake, also known as the Great Kobe Earthquake or the Great Kansai Earthquake, occurred on January 17, 1995 in the Kansai region of Japan. The epicenter was located in the Akashi Strait southwest of Kobe and was an earthquake event with a maximum magnitude of 7.3. The Great Hanshin Earthquake played an important role in Japan’s earthquake history. Many Japanese scholars at the time believed that the probability of a major earthquake occurring in the Kansai region was very low, so the region lacked adequate disaster prevention measures and emergency relief systems. In particular, many traffic routes around Kobe had to pass through tunnels and viaducts. Traffic routes were severely damaged during the earthquake, which greatly affected the speed of search and rescue operations and caused many casualties. Therefore, it can be said that the occurrence of the Great Hanshin Earthquake directly prompted the strengthening of related measures such as earthquake science research, earthquake resistance of urban buildings, and earthquake resistance of transportation.
Earthquakes in Japan: Tohoku Pacific Coast Earthquake (311 Great Earthquake)
The Tohoku Pacific Coast Earthquake, or the 311 Great Earthquake as it is better known to the general public, occurred in the Tohoku Sea of Japan on March 11, 2011. The epicenter was off the Pacific Ocean east of Sendai City, the capital of Miyagi Prefecture, and it was the first earthquake in Japanese history to record a magnitude greater than 9. In addition, the huge tsunami caused by the 311 Earthquake brought a series of more devastating events. These included the famous Fukushima nuclear disaster, which caused a large-scale paralysis of life functions and stagnation of economic activity in Japan, and was at the time the largest natural disaster to hit mainland Japan in decades.
Earthquake in Japan: Kumamoto Earthquake
The Kumamoto Earthquake occurred on Kyushu Island in southwestern Japan on April 16, 2016, with its epicenter in Kumamoto Prefecture in central Kyushu, and had a maximum magnitude of 7. The earthquake collapsed many buildings in Kumamoto Prefecture, damaged traffic roads, fell roof tiles on the castle tower of Kumamoto Castle, an important cultural property, and destroyed the castle walls. After the disaster, Prime Minister Shinzo Abe instructed relevant agencies to quickly grasp the disaster situation, but Emperor Akihito and Empress Michiko also canceled their visit to Shizuoka and expressed their condolences to the victims of the disaster in Kumamoto Prefecture.
Earthquake in Japan: Noto Peninsula Earthquake
The Noto Peninsula Earthquake occurred on January 1, 2024 on the Noto Peninsula in Ishikawa Prefecture. The earthquake was located 42 kilometers northeast of Anamizu Town, Ishikawa Prefecture. It is the widest range since the Japan Meteorological Agency implemented the Earthquake Early Warning and involves long-term vibrations. Long-term vibrations resonate to higher floors, shaking longer and harder. Long-term vibrations have the characteristic of propagating over long distances, and even prefectures and cities hundreds of kilometers away may be affected. This earthquake caused many buildings to collapse in Ishikawa Prefecture, making it one of the largest earthquakes since 2024.
What’s on a Japanese plate?
Those of us who grew up in Taiwan before knowing the Japan Plate know that Taiwan is an island country located between two plates, the Philippine Sea Plate and the Eurasian Plate, and the seismic movement is already very active. But in comparison, Japan is a country that sits between four major plates: the Eurasian Plate, the North American Plate, the Pacific Plate, and the Philippine Sea Plate! For this reason, seismic activity is very frequent in Japan, but what exactly are the relative positions of these plates? Do you have any interesting knowledge again? One by one in this paragraph!
Eurasian Plate
The Eurasian Plate is one of the largest plates in the world, covering most of the Eurasian continent and the Middle East, bordering western Japan. The boundary between the Eurasian plate, the African plate and the Indian plate is an area where earthquakes occur frequently, and the mutual pressure between the plates has also created many different landforms. For example, the Himalayas are the result of the Indian Plate pressing against the Eurasian Plate.
Philippine Sea Plate
The Philippine Sea Plate is a relatively small plate with a distribution area located in the waters around the Philippines, bounded by the Philippine Islands, Taiwan and Ryukyu Islands in the west, Japan in the north, the Mariana Trench subduction zone in the east, and Yap Island, Palau and the easternmost islands of Indonesia in the south. The collision between the Philippine Sea Plate and the Eurasian Plate caused the formation of Taiwan Island, and this process continues today.
Pacific Plate
The Pacific Plate is the largest major plate in the world, with an area of more than 100 million square kilometers. It generates a fault zone that meets the North American Plate and the open sea of eastern Japan, namely the famous Mariana Trench.
North American Plate
The North American Plate is the main plate of North America, covering most of North America, including regions such as Canada, the United States, Mexico, and Greenland. The southern boundary of the North American Plate is bordered by the Eurasian Plate and the Philippine Sea Plate in central Japan.
The above is the distribution of the four major plates in Japan, and the rich geological topography such as uplifts, folds, and faults generated by plate compression is of great significance in studying the evolutionary process of the earth.
Where are Japan’s faults distributed?
In particular, as mentioned above, Japan is located at the boundary of the Eurasian Plate, Philippine Sea Plate, Pacific Plate, and North American Plate. According to the Geological Survey of Japan, Japan, which is located in an earthquake zone, has 114 fault zones in the country! This is why earthquakes occur so often in Japan!
Japan Central Structural Line
Among them, the most famous and important fault system in Japan is the Central Structural Line, a geological structure that runs through central Japan and includes multiple parallel and intersecting faults, extending from Kanto to Kyushu, with a total length of 360 kilometers, equivalent to the driving distance from Taipei to Kaohsiung. Because this central structural line moves in large quantities between different geological areas, it forms a boundary line, with different rocks arranged on both sides. It is one of the longest and most important faults in Japan and the main source of earthquake activity in Japan. However, it must be noted that the central tectonic line runs through Japan’s mountains, rivers, and plains, and has a profound impact on Japan’s topography and topography, but it is not a plate boundary.
In addition, the Central Structural Line is an active fault system, and the Japan Earthquake Research Committee has strengthened its investigation of faults in various parts of Japan since the Great Hanshin Earthquake in 1995. Investigations have found that if a fault called the Central Structural Line ruptures, it could trigger an 8.0-magnitude earthquake and reach a maximum magnitude of 6 to 7 in various places, so authorities hope to relocate buildings in the fault zone to mitigate damage caused by the earthquake.
What is the intensity of earthquakes in Japan?
According to the Japan Meteorological Agency’s “Explanatory Table on Earthquake Intensity Grades” created by the Japan Earthquake Research Committee, this is an indicator that the Japan Meteorological Agency describes the seismic intensity of earthquakes in Japan! The seismic intensity classes of earthquakes in Japan range from Magnitude 1 to Magnitude 7, and each represents the impact of different earthquake intensities on humans. The specific contents are as follows:
| Grade | Seismic intensity | Human behavior |
| Level 0 | 0–0.4 | People couldn’t feel the vibrations, but seismometers recorded them |
| Level 1 | 0.5–1.4 | People can feel a little shaking when they are stationary or on high floors. |
| Level 2 | 1.5–2.4 | Most people may feel shaking, which may wake a sleeping person. |
| Level 3 | 2.5–3.4 | Most people can clearly feel the shaking, and people walking outdoors can also feel the shaking |
| Level 4 | 3.5-4.4 | Considerable sense of dread, some seeking refuge, some waking from slumber |
| 5 Weak | 4.5-4.9 | Most people are afraid and want to hold on to strong objects |
| Top 5 | 5.0–5.4 | Most people have difficulty walking and cannot move without grasping solid objects |
| 6 Weak | 5.5–5.9 | Hard to stand due to violent shaking |
| Top 6 | 6.0–6.4 | Unable to stand due to severe shaking |
| Level 7 | 6.5 or more | Become unable to move autonomously due to violent shaking |
When an earthquake occurs, the news often uses the above nouns to describe the intensity and degree of impact of the earthquake. These descriptions are relatively intuitive and can help the public better understand and grasp the intensity of the current earthquake.
Earthquake prediction map of Japan!
The figure below is a national earthquake prediction map created by the Japan Earthquake Research Promotion Headquarters in 2020. It predicts the probability and location of earthquakes in Japan over the next 30 years. Although this Japan Earthquake Forecast Map cannot fully grasp the timing of earthquakes in Japan, prevention and contingency measures can be planned according to the probability of earthquakes occurring in this region. Detailed report contents are summarized below!
Earthquake prediction map of Japan: 1. Earthquake prediction probability map
The upper left block is the Japan Earthquake Prediction Probability Map. Based on the location, magnitude, and probability of all Japanese earthquakes currently under consideration, the probability and intensity of earthquakes at each location are collectively calculated and distributed.
Earthquake prediction map of Japan: 2. Earthquake prediction map of specific focal faults
The upper right block is a Japan earthquake prediction map of specific focal faults, which can be used to calculate the magnitude and distribution of earthquakes in a specific area, and can also be used to indicate the range of populations affected by a certain magnitude or higher in that area. Using the northern section of the Itoigawa-Shizuoka structural line fault zone as an example, this is a map showing the affected area and the range that will affect the population with a seismic intensity of less than 6 or higher in the event of a local earthquake.
Earthquake Prediction Map of Japan: 3. Characteristics of the 2020 Edition of the National Earthquake Prediction Map
The bottom block is the 2020 version of Japan Earthquake Prediction Map, with the following changes compared to the 2018 version.
- In particular, improvement of earthquake models where focal faults are difficult to identify in advance (taking into account seismic activity in the Tohoku Pacific Ocean)
- Improvement of underground structure model
- Change of evaluation reference date for earthquake occurrence probability assessment to January 1, 2020
- Changing the color scheme of the earthquake prediction map
- Earthquake prediction maps by region and prefecture released
To summarize the above, the probability graph of the report results shows that the probability of earthquakes is high in southeastern Hokkaido, some areas of the Sendai Plain, Tokyo Metropolitan Area, the Pacific side of the Tokai-Shikoku region, and areas around the Itoigawa-Shizuoka structural line fault zone within the next 30 years.
What is Japan’s earthquake countermeasures?
Because it is located at the boundary of plates, earthquakes occur frequently in Japan. After the Great Hanshin Earthquake and the Great 311 Earthquake, Hagama Shenzhou emphasized earthquake disaster prevention, and various circles actively cooperated with government and private disaster prevention policies. Therefore, disaster relief and disaster prevention work is now the most important task. In Japan, we are also proposing many disaster prevention measures to ensure the safety of people’s lives and property, such as improving the Basic Law on Disaster Countermeasures, promoting disaster prevention sand trays, constructing disaster prevention parks and bases, strengthening earthquake resistance of buildings, strengthening buildings around emergency roads, fire prevention in densely wooded areas, and emergency medical care. Next, let’s take a look at what kind of disaster prevention measures Japan has!
Earthquake Countermeasures in Japan: Establishment of Evacuation Shelters
The Japanese government has set up large disaster prevention parks and small evacuation parks as bases for relief and recovery activities. These open spaces provide a relatively safe space, and many facilities are built and available, such as landing points for helicopters to transport supplies, temporary toilets, solar lights, emergency water supply, and vending machines.
Japan’s Earthquake Countermeasures: Promotion of Earthquake Resistance Measures
In order to mitigate the damage caused by earthquakes and protect the lives and property of residents, the Japanese government is working to improve disaster resistance by systematically making houses and buildings earthquake-resistant. Specific measures include earthquake-resistant transportation roads, non-combustible and earthquake-resistant areas with dense wooden houses, and earthquake-resistant important buildings.
Earthquake Countermeasures in Japan: Disaster Prevention Organization and Association
The Japanese government is promoting a disaster prevention worker system. A disaster preparer is defined as a person who actively participates in improving disaster preparedness capabilities in all corners of society, is certified by relevant organizations, cooperates with the government’s rapid response in the event of a disaster, and assumes the role of evacuation, rescue, and shelter management.
Earthquake Countermeasures in Japan: Disaster Prevention Geographic Information System
The Japanese government is continuously promoting the digitization of the country, and the location information of disaster prevention facilities, wooden houses, roads, infrastructure, etc. can be grasped through the layers of electronic maps. The government can better understand the characteristics of each geographical location and determine areas where protective measures need to be increased to respond to potential disaster risks.
Earthquake Countermeasures in Japan: Installation of Disaster Prevention App
The Japanese government is promoting disaster prevention apps (APPs) that provide functions such as earthquake warnings, disaster information, shelter information, and rescue guidelines. Disaster prevention apps help you get important information in a timely manner when an earthquake occurs and take appropriate action.
