TOKYO – Sept 1 marks a century since a magnitude-7.9 earthquake struck the Kanto region surrounding Tokyo, leaving some 100,000 people dead or missing, while fires razed much of the city to the ground. 

Government experts see a 70 per cent chance of a magnitude-7 earthquake taking place right underneath the capital within the next three decades, which could cost 95 trillion yen (S$878.8 billion) in economic damages, according to estimates. 

That looming threat keeps Tokyo on its toes. In 2022, it earmarked 15 trillion yen for natural disaster resiliency projects till end-2040.

It also periodically revises its earthquake disaster management plan, most recently updating it in May to reflect demographic shifts and post-pandemic considerations such as the growth in remote work and the need to prevent infectious diseases from spreading in a crowded evacuation centre. 

Even after all these efforts, there is no end to how much the city can prepare. 

“It’s very important to be imaginative to prepare for as many scenarios as possible,” said Mr Akihiko Hamanaka, a director at the Tokyo Metropolitan Government’s disaster prevention division. “No earthquake disaster is the same – it’s all different depending on the epicentre, the size, the weather at the time.” 

Here are some of the ways that Tokyo is preparing for the next big quake. 

Fireproofing  

The majority of deaths in the 1923 quake occurred because of fires. The earthquake struck around noon, right when residents were preparing lunch. 

Today, a belt of neighbourhoods with old wooden structures densely packed together – nicknamed mokumitsu in Japanese as an abbreviation for the words “wood” and “dense” – surround the core of the city’s modern centre. These areas were built as a result of haphazard urbanisation amid the economic and population boom after World War II.

There were about 8,600ha of such at-risk areas as at 2020, roughly 14 per cent of central Tokyo, according to the city’s Bureau of Urban Development. 

Following the massive earthquake that struck north-eastern Japan in 2011, Tokyo redoubled its efforts to fire-proof such neighbourhoods by offering subsidies and tax breaks to clear old structures and replace them with new, disaster-resilient ones. The plan includes clearing buildings to widen roads to act as firebreaks and provide access to emergency responders.

The strategy is important, but it takes a lot of money, time and the understanding of landowners and the local community to complete. Residents of these areas tend to be elderly people who have lived there for decades, and might be reluctant or financially unable to relocate. 

While mitigation measures like fireproofing are necessary, they need to be implemented in parallel with softer measures such as evacuation drills, said Dr Osamu Murao, professor at Tohoku University’s International Research Institute of Disaster Science.

“It’s about being prepared, so that in the event of a disaster, at the bare minimum, people’s lives are protected. Communities need to know where to evacuate to and what route to use to evacuate, and so on,” he said. 

Bolstering buildings 

The 1923 disaster led to the amendment of Japan’s Urban Building Law, which included the nation’s first seismic standards for structures. 

Since then, building codes have been improved in response to subsequent earthquakes, as researchers and policymakers incorporated new technologies and engineering methods to make ever more resilient buildings. The last major changes to the building codes were made in 1981. Today, Japan boasts some of the most stringent building regulations in the world. 

Municipalities within Tokyo have provided subsidies for home owners looking to retrofit their homes to withstand earthquakes. There is also financial support for schools, social welfare facilities, hospitals and other structures to make them more quake-resilient. 

Standards for wooden structures were revamped in 2000, requiring architects to consider things like the number of quake-resistant walls with braces. Ground surveys must also be conducted to ensure a building’s foundation is suitable for the site. 

As part of its long-term resilience project, Tokyo plans to expand subsidies for quake retrofitting projects to cover 200,000 or so wooden buildings built between 1981 and 2000 that are at risk.

Designated roads   

Drivers in Tokyo may come across road signs in Tokyo that feature a cartoon drawing of a blue catfish alongside the words “Emergency road: closed in the event of major earthquake”. A popular Japanese myth says that a large catfish lives underneath the earth and causes earthquakes when it moves. 

These are roads that have been designated by law to be used by emergency responders during a natural disaster. In the event of a major quake, regular motorists will be banned from driving down those roads, clearing the way for ambulances, firefighters and delivery of goods. 

To make sure the roads remain clear and accessible, Tokyo is working to strengthen structures in emergency roads, mandating owners of buildings along the path to report the seismic resilience of the structure and conduct necessary retrofits. 

Raising awareness  

Softer measures are as crucial as infrastructure projects, Mr Hamanaka said. While neighbourhood organisations in the city have typically conducted disaster drills at a local level, participation in such groups and activities has fallen as residents are getting older.

The government designated Sept 1 as Disaster Prevention Day in 1960 to commemorate the 1923 disaster and raise awareness for the floods and heavy rain from typhoons that hit Japan during the season. Local governments, schools and companies typically hold drills on the occasion. 

In 2015, the Tokyo government issued residents a yellow guidebook that outlines everything from how to respond in a variety of natural disasters to step-by-step plays of what the first several days of a disaster could be like, to tips on how to build makeshift toilets from cardboard boxes and newspapers. The authorities are considering revamping the guidebook on the occasion of the 1923 quake anniversary, Mr Hamanaka said. 

The national and local governments, along with schools and companies, are also using the 100-year mark as an opportunity to raise awareness of earthquake preparation. 

Special websites have been set up by ministries, agencies and local governments with historical content of the events of 1923. Museums are holding special exhibitions about the disaster – a display in Yokohama explains how the disaster impacted ports and ships in the area. Utility Tokyo Gas held a comprehensive disaster drill under a doomsday scenario of an earthquake and typhoon happening at the same time. 

Tokyo also has several disaster prevention parks, ordinary public spaces that can be turned into evacuation sites with solar power generation systems and emergency water tanks. Tokyo Rinkai Disaster Prevention Park by Tokyo Bay has a disaster learning facility, where visitors can use tablets to navigate dioramas and learn how to survive the first 72 hours of a major earthquake. 

Alert systems

Areas outside Tokyo are at as much risk of earthquakes, as seen from the quakes that hit Hokkaido in 2018 and the southern prefecture of Kumamoto in 2016. 

Japan has developed a world-leading warning system that gives people time to prepare and brace themselves for a jolt. A network of seismographs has been placed throughout the country to detect the initial waves when an earthquake occurs. 

The system calculates the data to estimate the potential size and location of the quake. If it detects a shake of a certain size, warnings are issued to phones and TV screens, and to factory lines and trains to automatically halt before the damaging secondary wave hits.

The early warning system has been hailed by the government as a unique tool Japan has developed, but critics have pointed out that the technology may be useful only for people farther away from the epicentre to have a brief moment to duck and cover. 

The alert system is not foolproof. In 2020, a false alarm that mistook the epicentre of an earthquake rattled residents in Tokyo and 14 other prefectures, urging people to prepare for a magniture-7.3 earthquake that did not come. BLOOMBERG