Life on the Pacific Ring of Fire is never really calm and sometimes dangerous. This also applies to Japan, because experiencing earthquakes in Japan is almost part of everyday life. Volcanic eruptions or tsunamis also happen much more frequently here than in large parts of the rest of the world. Every month, an average of more than 70 earthquakes with a magnitude of over 4.0 shake the country – about 17 times a year, the earth even shakes with a magnitude of over 6.0 on the Richter scale. Recently, German media also reported that the Sakurajima volcano has erupted again – however, this is not uncommon for the permanently active volcano near Kyushu. There are more than 240 volcanoes in Japan, of which more than 40 are considered to be very active.
But why is the risk of natural disasters so high in Japan and how do the Japanese provide protection from the forces of nature??
Geographical location causes earthquakes in Japan and creates many volcanoes
The name "Pacific Ring of Fire does not come from nowhere. The earth’s crust consists of several plates that are constantly in motion, with Japan being located on a so-called Fracture zone lies. Near Japan, the Eurasian Plate and the Philippine Plate collide, and from the east, the Pacific Plate pushes under the other two plates. A particularly large number of volcanoes are formed at the edges of such plates, which have been more or less active for millennia due to constant movement. Since the Japanese islands have a large north-south extension along the Pacific Plate, it is not surprising that there is a whole chain of volcanoes in this country. Plate tectonics is also responsible for about 1500 earthquakes in Japan every year – and severe seaquakes also increase the risk of tsunamis on the Japanese coast. Along the Izu-Bonin-Mariana island arc, volcanic activity is even creating new islands, such as the volcanic island of Nishinoshima, which emerged in 2013 and is located about a thousand kilometers southeast of Tokyo and now measures about four square kilometers.
Destructive forces of nature in Japan shape the country and its inhabitants
Again and again, however, the destructive side of the Natural forces in Japan. In the last centuries there were natural disasters in Japan, which were devastating and left a lasting mark on the country. From the recent past, the 2011 Tohoku earthquake should be familiar – a strong seaquake that struck on 11. March 2011 off Miyagi Prefecture on Japan’s east coast. With a magnitude of 9.0, it is one of the five strongest earthquakes in the world – surpassed only by the Valdivia earthquake (Chile, 1960, magnitude 9.5), the Good Friday earthquake (Alaska, 1964, magnitude 9.2) and the Indian Ocean earthquake off Sumatra (26. December 2004, magnitude 9.1). By the way, due to the force of the earthquake and the numerous strong aftershocks, the main island of Honshu was shifted by 2.4 meters to the east and the coasts sank by as much as 40 to 120 cm, which increased the danger of flooding in these areas.
Japan has often experienced tsunamis. Giant waves are triggered by seaquakes and pile up meters high off the coast; when they hit land, they sometimes sweep away everything for miles inland. But the tsunami that immediately followed the 2011 Tohoku earthquake not only devastated large parts of the Tohoku region in northeastern Japan and claimed the lives of thousands of people – it triggered a nuclear catastrophe at the Fukushima nuclear power plant. Since then, large parts of the region are uninhabitable. As a result, the Japanese government successively shut down all 17 nuclear power plants (with a total of 54 nuclear reactors) in the country. However, at least since August 2015, when the Sendai nuclear power plant in southern Japan came back online, it became clear that the Japanese government still has no plans to phase out nuclear power, even though 11 reactors nationwide were finally shut down after the nuclear disaster at Fukushima.
But even before 2011, there were earthquakes in Japan that were devastating. The Great Kanto earthquake am 1. September 1923 for example, destroyed the port city of Yokohama and large parts of Tokyo, especially the districts west of the Imperial Palace. More than the earthquake itself, the subsequent fires reduced the two cities to rubble, mainly because of the many traditional wooden buildings that quickly caught fire. The few western brick houses had mostly already collapsed due to the earth tremors. In total, there were more than 142.000 fatalities.
Especially the prefectures of Aomori, Iwate and Miyagi in northeastern Japan have been battered by earthquakes and tsunamis in the past. In addition to the 2011 disaster, there were also devastating seaquakes off the coast in 869, 1611, 1896, and 1933 that triggered tsunamis. But also Tokyo is located in a tectonic fault zone, which has been hit by a major earthquake about every 70 years so far.
Japan, the land of typhoons, volcanic eruptions, landslides and heavy snowfalls
Besides earthquakes Japan is regularly hit by numerous typhoons from August to October, Which, in addition to violent winds, also bring large amounts of precipitation and cause storm surges on the coasts. Because Japan is basically a mountain range rising from the sea, most of its surface has a slope of more than 8 percent, which – especially in the rainy season – can cause landslides Landslides favored, such as the landslide near Hiroshima in August 2014.
In the far north on Hokkaido there is no rainy season, but here in winter humid air masses from the direction of Siberia regularly cause Heavy snowfall. Meter-high snow mountains are not uncommon. Despite the good adaptation to this climate, it therefore often comes to kilometer-long traffic jams and power outages.
In the story, because of the many Volcanoes in Japan major eruptions naturally occurred again and again. Especially Mihara, Miyake-jima and Torishima off the Izu Peninsula, Ohachi and Sakurajima on Kyushu, Usu and Komagatake on Hokkaido and Asama in Gunma have erupted more and more in the last 500 years. However, the number of fatalities and the amount of damage are normally hardly comparable to those in major earthquakes. Overall, most volcanic eruptions in Japan have had no or few fatalities. The exception to this was, for example, the tsunami that struck in 1741 Eruption of the Oshima volcano on the volcanic island of the same name off the coast of Hokkaido. Took the lives of more than 1600 people and destroyed numerous homes and ships. On Honshu in the year 1783 there was a severe eruption of the volcano Asama (the most active volcano on the island), which killed about 1,500 people from lava flows and flooding. As a result of the large amounts of ash ejected, solar radiation decreased and hundreds of thousands of people died in a famine in the years that followed. However, the most consequential eruption occurred 1792 on Kyushu. At the Uzen volcano complex there was a violent eruption, with a subsequent earthquake causing one of the volcanoes to collapse. The triggered avalanche shot into the ocean, the ensuing tsunami destroyed the city of Shimabata, more than 15.000 people died as a result of the landslide and the tidal wave. Nevertheless, volcanoes in Japan generally do not pose as great a danger as one might expect from their number. Japan’s most famous volcano, Mount Fuji, is considered to be active with a low risk of eruption. The mountain has been dormant since 1708 and has become one of the most popular destinations for hikers.
How to face and protect against natural disasters in Japan
Because of the large number of stronger earthquakes each year, the Japanese take earthquake prevention very seriously. In 1960, the Japanese government declared the 1. September to Disaster Prevention Day, to regularly remind the population of how essential preventive measures are. Apart from this, above all earthquake-resistant buildings into focus. Since the Great Kanto Earthquake, for example, reinforced concrete has become the predominant building material for Japanese houses, since the few buildings made of reinforced concrete had proved to be the most resistant after the quake and the following fires. Steel-reinforced bricks are also used to build houses, and high-performance fiber composites can be used to make buildings more (more) earthquake-resistant, even retroactively. In general, thanks to the investment in safer construction methods for Japanese houses, major damage caused by earthquakes has been prevented both in large cities and in the countryside.
As a result of the 1995 Kobe earthquake, building regulations in Japan were further tightened – since then, earthquake-resistant buildings have become even more of a priority. Skyscrapers in particular, which are numerous in metropolises such as Tokyo, must survive major earthquakes as undamaged as possible. The dynamic properties of structures and the subsoil must be taken into account at the planning stage. Structural changes require explicit approvals. Earthquake-resistant construction also includes making it impossible to escape or. the rescue of human lives must be possible. However, the disaster at the Fukushima nuclear power plant has shown that regulations are not yet sufficient, especially in such sensitive buildings. After the event, new regulations were enacted to not only make such buildings earthquake-resistant, but also to protect them from tsunamis. However, implementation is slow and it is not yet clear whether the new measures will be sufficient in the event of an emergency.
Incidentally, earthquake drills are already part of everyday life in schools. Children regularly learn the most important rules of conduct in the event of an earthquake, such as taking shelter under a table and staying away from windows. Especially on 1. September, there are drills in schools, office buildings and factories across the country, training the correct behavior during earthquakes. Since the Japanese are accustomed to minor earth tremors, they are not affected in their everyday lives. There are no panic outbreaks in Japan – unless it was a very strong quake.
Early warning systems help the Japanese to get to safety
The large number of earthquakes in the past gives Japan an advantage in earthquake research, because it has access to extensive data on earthquakes and their effects. This puts Japan at the forefront of earthquake prediction and prevention. One of the most important means of limiting casualties and damage is the nationwide early warning system, which uses the extensive experience of earthquake research and warns the population via cell phones and the media. For this purpose, so-called accelerometers were installed in the earth at a distance of about five kilometers, which respond to strong seismic waves. In the warning system, the many times higher speed of radio waves compared to earth vibrations is used to close gas/water lines, to activate emergency generators and to shut down power plants in time. Interestingly, it is possible to send an alarm to the population about five seconds before the earthquake – depending on the distance to the epicenter. Radio stations and mobile providers immediately relay the alarm as a warning tone to their listeners and users, so that they can theoretically get to safety in time under a table, in the door frame or in other places. In addition, the alarm immediately brings high-speed trains (Shinkansen) to a halt to prevent derailment. Enable the early warning system as well as a clear delimitation of the endangered area by highly precise measuring instruments. Still, the big quake of 2011 showed that earthquake magnitude predictions have proven increasingly unreliable. In recent decades, earthquakes have become increasingly powerful in Japan, so more measures are planned to better protect people from natural disasters.
The Early warning system works for volcanic eruptions but still very good. So far, in the vast majority of cases, people have been able to evacuate in time, if evacuation was necessary at all. Only in rare cases have researchers and population alike been surprised by an explosive outbreak.
The 1896 Meiji-Sanriku earthquake and subsequent tsunami, which claimed many lives in the Tohoku region, prompted Japan Tsunami To go ahead with research and expand the early warning systems for flood waves. You try to protect yourself against the floods with big dams and breakwaters. However, the dams are often breached by roads, so local firefighters need about five minutes’ warning to close the gates. In order to provide enough lead time, there are in Japan Tsunami Warning systems, using records from geological stations. Three stations are enough to determine the strength and location of the seaquake, as well as the direction of the earth tremors, and thus to detect a tsunami threat. Although the population can be warned so mostly short term, this is often not enough to seek shelter in time or. to evacuate the population in the areas likely to be affected.
In general, warning systems are very expensive to purchase and maintain, but regularly contribute to a significant reduction in damage and, more importantly, to saving lives. Natural forces in Japan are and will remain dangerous, but the Japanese have at least learned to live with the smaller earthquakes, volcanic eruptions and the typhoons in late summer. Nevertheless, nature remains unpredictable, even if thanks to modern technology and years of experience, risks can be minimized.