Is Japanese manga ‘megaquake’ possible on July 5 or have Hongkongers lost plot?

The plot of a Japanese manga has played a big role in fuelling online rumours about a “megaquake” striking Japan on Saturday, triggering fear among some Hongkongers and a decline in interest in trips to the country, a hugely popular destination for residents. But are the claims made by the comic book artist, based on her dreams, possible? The Post has gathered expert opinions to debunk the speculation. 1. Why have concerns about megaquakes arisen? The Japan Meteorological Agency last August issued its first-ever “megaquake advisory”, saying that there was a 70 to 80 per cent chance of a magnitude 8 or 9 earthquake connected to the Nankai Trough occurring within the next 30 years. It issued the advisory after warning that a magnitude 7.1 quake that struck Japan on the western edge of the trough earlier that month raised the likelihood of a strong one. The trough is an 800km (500-mile) undersea trench running from Shizuoka, west of Tokyo, to the southern tip of Kyushu Island and sits where two tectonic plates meet. This April, the Japanese government estimated that up to 298,000 people could die if a megaquake of about magnitude 9 occurred along the trough. The announcements triggered widespread online discussions and even rumours where people drew connections to predictions made by feng shui masters and a manga titled The Future That I Saw, Complete Edition. The manga, first published in 1999, was based on the dreams of artist Ryo Tatsuki. It warned of a major disaster in March 2011, a date which coincided with a cataclysmic earthquake that struck Japan’s northern Tohoku region that month. Its latest edition, published in 2021, claimed that July 5 would be the date for another megaquake. 2. Can the exact timing of earthquakes be predicted? The Japanese agency last month said it was impossible to forecast the specific timing, location or magnitude of an earthquake, calling any such prediction “a hoax” and “disinformation”. Chan Lung-sang, a visiting professor of the department of Earth and planetary science at the University of California, Berkeley, also said the manga prediction was not based on science, and it was impossible to predict the exact timing of an earthquake. “I think it’s strictly a fantasy or fictitious … We would not be able to make such a prediction at all. The science is not there yet,” he said. “There will be about an 80 per cent chance that a magnitude 7 earthquake will occur along that Nankai Trough within the next 30 years so we are talking about a period of 30 years, not a particular day.” He said if the earthquake did not happen in the next 30 years, there would be a higher risk of one later in the future. The Japanese authorities made their predictions by working out the statistical average of the return period for earthquakes over a long period of time, he added. Tatsuki reportedly earlier said that she was “not a prophet”, urging people not to be “overly swayed” by her dreams and to “act appropriately based on expert opinions”. 3. Could a quake connect regions? The manga also reportedly claimed that the megaquake would lead to tectonic plate movements, connecting regions such as Hong Kong, Taiwan and the Philippines. But Chan said such things might only happen over a long period of time and “definitely not in our lifetime”. “All these earthquake events are caused by what we call plate motions because the surface of the Earth, the uppermost layer of the Earth, is divided into a number of plates like a cracked boiled egg,” he said. “The egg shell is cracked and then each fragment is a plate and they move, but the movement is very, very slow. We’re talking about a few centimetres per year.” 4. Is a magnitude 10 earthquake possible? Chan said while the 2011 earthquake in Japan reached a magnitude of 9, which was substantial, it would be almost impossible for an earthquake to hit 10. He said earthquakes occurred when plates moved and collided with each other, and the more active the motions, the more earthquakes the regions experienced. Earthquakes occur when rocks along a fault line – a crack or a fracture in the Earth’s crust – suddenly fracture and slip past each other, causing a release of energy. But Chan said there was an upper threshold for the magnitude as the Earth’s crust could only bear a particular level of force. “We would not see very big earthquakes like magnitude 10, because earthquakes like that will exceed the strength of the rock,” he said. “The rock will basically fracture before the energy can come to that level.” He said if there was an earthquake in Japan, by the time the earthquake waves reached Hong Kong, the impact would be very small. 5. How have people reacted to the predictions? Some Hongkongers became convinced by the manga claims, with travel agencies reporting a drop in demand for Japan tours. Hong Kong Airlines also cancelled flights to Kagoshima and Kumamoto in Japan in July and August, citing sluggish demand for tourism in the country. Baniel Cheung Tin-sau, an adjunct associate professor of the University of Hong Kong’s business school, said Japanese people had also noticed such speculation among Hongkongers, but most of them did not believe the rumours. Cheung, who has expertise in Japanese business and cultural management, said television stations, YouTubers and internet users had also begun discussing such beliefs among Hongkongers. “Japanese people are very scientific. From a young age, the government and schools have educated them about when earthquakes occur, how high the risks are, how to handle them, and what assistance the authorities will provide,” he said. “They may think Hongkongers, who believe speculation that does not come from the government, science or data, are very ignorant.” He added that Japanese people had encountered earthquakes all their lives and were well-prepared for such situations. 6. What do experts say about Hongkongers’ concerns? Chan said his colleagues in the United States had heard about the Japanese advisory but not the manga prediction. He said Hongkongers’ reactions reflected a lack of common sense, adding that stronger education on hazard awareness and preparation was needed. “Earthquakes will come regardless of what you do. They will come about. I think most important is education, awareness, and how to prepare for one,” he said. Cheung said the panic could be caused by exaggeration on social media, noting that people did not spend much time verifying the information they saw online. He said Hongkongers rarely experienced large-scale disasters such as earthquakes, volcanic eruptions or warfare, which could lead to weak hazard awareness and a gap in knowledge.

Is Japanese manga ‘megaquake’ possible on July 5 or have Hongkongers lost plot?

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Comic book predictions of a massive Japanese earthquake have sparked fear among some Hong Kong residents. The Post debunks the rumours

.css-1mniedq{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;}1. Why have concerns about megaquakes arisen?

Comic book predictions of a massive Japanese earthquake have sparked fear among some Hong Kong residents. The Post debunks the rumours

1. Why have concerns about megaquakes arisen?