Earthquake swarms are fueling fear of the ‘big one’ in Japan

Earthquake swarms are fueling fear of the ‘big one’ in Japan


More than 1,300 earthquakes have hit Japan’s Tokara Islands in two weeks, prompting evacuations of dozens of residents from the remote archipelago on the country’s southern tip.

Although no major damage has been reported and no tsunami warnings have been issued, the Japan Meteorological Agency has cautioned that tremors as strong as a β€œlower 6” on Japan’s seven-stage seismic intensity scale β€” such as one that occurred Thursday β€” may continue.

Lower 6 indicates an intensity that may make it difficult for people to stand without holding on to stable support.

People walk past collapsed buildings after a quake in Wajima, Ishikawa Prefecture, Japan, on Jan. 2, 2024.

People walk past collapsed buildings after a quake in Wajima, Ishikawa Prefecture, Japan, on Jan. 2, 2024.

(Associated Press)

β€œThe seismic activity remains dynamic,” JMA official Ayataka Ebita said at a news conference Sunday β€” and that has fueled fears of a megaquake.

The temblors have coincided with viral panic stemming from the 2021 reprint of a comic book that many are now interpreting as a clairvoyant prediction of a major earthquake. β€œThe real disaster will come in July 2025,” read the cover of manga artist Ryo Tatsuki’s β€œThe Future that I Saw.” The graphic novel, which explores Tatsuki’s dreams, also features a panel that says β€œthe ocean floor between Japan and the Philippines will crack.”

In recent months, that prediction has become the subject of intense online speculation. It has even spread to nearby countries like Hong Kong, where it has been blamed for a recent dip in tourism to Japan.

Last month, Hong Kong Airlines suspended all flights to the southern Japanese prefectures of Kagoshima and Kumamoto, citing low demand.

In South Korea, earthquake panic has been cited as a reason for the cheapness of flights to Japan compared with last year, although industry experts have said that there are other factors at play: increased competition between airlines and a stronger yen that reduces the buying power of South Korean tourists.

On Saturday, South Korean singer Taemin of the band SHINee, who was in Japan for a concert, referenced Tatsuki’s prediction in a livestream, assuring fans he was safe and jokingly saying an earthquake might make his performance β€œlook cool.”

But faced with backlash for making light of a natural disaster, he later issued an apology in Japanese and Korean.

There is a reason why a comic book’s scientifically baseless prediction is currently gaining so much traction: Tatsuki was (sort of) right before. The first edition of the graphic novel, published in 1999, referenced a β€œmassive disaster” in March 2011 and contained lines like: β€œI dreamed of a great disaster. The waters of the Pacific Ocean south of the Japanese archipelago will rise.”

A CHP officer checks damage after the Loma Prieta earthquake in San Francisco on Oct. 17, 1989.

A California Highway Patrol officer checks the damage to cars that fell when the upper deck of the Bay Bridge collapsed onto the lower deck after the Loma Prieta earthquake in San Francisco on Oct. 17, 1989.

(George Nikitin / Associated Press)

That prediction seemed to come true with the massive 2011 Tohoku earthquake, which killed over 19,000 people and triggered the tsunami that led to the Fukushima nuclear disaster. At an estimated $360 billion incurred in economic damages, the earthquake remains one of the costliest natural disasters in history. It registered 9.0 on the Richter scale, which measures the magnitude of the earthquake. Shindo, Japan’s seismic intensity scale, measures intensity at a specific location.

The coincidence catapulted Tatsuki to fame and made her manga a bestseller.

But in recent weeks, Tatsuki has tried to quell the panic over her latest prediction, saying in a statement issued through her publisher that she was β€œnot a prophet.”

β€œI believe that everyone should be free to make their own interpretation,” she told Japan’s Mainichi newspaper in May. β€œHowever, I think it is important to not get overly swept up in the process and to act appropriately in consideration of expert opinion.”

Japanese government officials and scientists have taken pains to debunk the theories, stressing that it is scientifically impossible to predict earthquakes with such accuracy.

β€œIt is absolutely a coincidence. There is no causal connection,” said Ebita of the JMA on Saturday. β€œIn Japan, earthquakes can happen at any time. Please be prepared, always.”

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Japan is one of the most earthquake-prone countries in the world, given its location within the Pacific Ring of Fire, a 25,000-mile-long belt of seismic and volcanic hot spots that loops around the perimeter of the Pacific Ocean, including the U.S. West Coast.

The country experiences about 1,500 earthquakes a year, or nearly a fifth of the world’s total, and earthquake evacuation drills are regularly practiced by government agencies and public schools.

On New Year’s Day last year, a magnitude 7.5 earthquake in Noto Peninsula in central Japan led to over 500 deaths and destroyed or damaged at least 37,000 homes.

Because they sit astride two overlapping tectonic plates, the Tokara Islands have long been prone to seismic activity such as β€œearthquake swarms,” a burst of relatively minor earthquakes occurring in quick succession that can last up to several months. (Southern California is another common site of earthquake swarms, though many are so minor they are barely perceived.)

The archipelago spans 12 individual islands β€” just seven of which are inhabited by a combined 660 or so residents β€” and the current swarm of quakes there is the most substantial since 1995. Two recent swarms that occurred in 2021 and 2023 exceeded just over 300 quakes each.

Although it’s unclear why the current swarm is so much greater than those instances, Takuya Nishimura, an earthquake expert at Kyoto University’s Disaster Prevention Research Institute, says it may be a result of volcanic activity.

β€œI suspect the subsurface movement of magma caused severe earthquake activity,” he said. β€œSeveral past studies show submarine volcanoes around the swarm region, which suggests the existence of magma under the ground.”

A strong earthquake, an estimated 7.4, struck the Noto region of Ishikawa Prefecture, in Japan on Jan. 1, 2024

A building collapses in Anamizu Town, Ishikawa Prefecture, on Jan. 2, 2024. An earthquake with an estimated magnitude of 7.4 struck the Noto region of Ishikawa Prefecture, in central Japan, about 4:10 p.m. the previous day.

(Noboru Hosono / Associated Press)

Despite the current viral attention around the Tokara swarm, experts like Nishimura are more concerned with another, far more credible earthquake forecast that has loomed over the country for years.

Earlier this year, a government panel estimated that there is an 80% chance of a magnitude 8 to 9 megaquake on the Richter scale occurring along Japan’s Nankai Trough in the next 30 years.

A 559-mile long fault line located off Japan’s Pacific coast characterized by its subduction, in which one tectonic plate is forced under another, the Nankai Trough has produced devastating earthquakes every 90 to 200 years. The last one occurred in 1946.

Under the government’s worst-case scenario, the next Nankai megathrust earthquake is projected to kill about 300,000 people β€” most of them likely to perish in the tsunamis reaching as high as 100 feet β€” and cause up to $1.8 trillion in damage.

By comparison, the death toll for the 1989 Loma Prieta earthquake and the 1994 Northridge earthquake β€” the two biggest seismic events in recent California history β€” was 63 and 57. In the meantime, experts are studying the southernmost tip of the San Andreas fault, which hasn’t had an earthquake of 7 or larger since sometime between 1721 and 1731.

β€œA future great Nankai earthquake is surely the most long-anticipated earthquake in history β€” it is the original definition of the β€˜Big One’,” wrote geologists Kyle Bradley and Judith A. Hubbard in 2024.

Earlier this month, the Japanese government announced a series of countermeasures aimed at reducing the number of deaths by up to 80% and structural damage by 50%, including making buildings more earthquake-resistant and improving evacuation protocols.

β€œIt is necessary for the nation, municipalities, companies and nonprofits to come together and take measures in order to save as many lives as possible,” Japanese Prime Minister Shigeru Ishiba said.

But Nishimura, the earthquake expert, says that more needs to be done to meet these ambitious targets.

β€œAlthough realizing the decrease in structural damage may be challenging due to a limited budget, reducing fatalities can be achieved through more soft-type countermeasures, such as training and evacuation drills,” he said.

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