In a country where disaster preparedness and historical memory have long been pillars of public trust, two recent waves of online falsehoods have left misinformation researchers deeply unsettled. In late July, after a powerful magnitude 7.1 earthquake struck off the coast of Kumamoto prefecture in southern Japan, a social media user posted what appeared to be a technical observation: seismic data from Japan’s National Research Institute for Earth Science and Disaster Resilience supposedly showed that the tremor was “not an earthquake but an artificial explosion waveform.” The post appeared barely 30 minutes after the ground stopped shaking, yet it spread with astonishing speed, gathering more than 2,100 reposts and 6,300 likes after being highlighted by Yahoo Japan’s real-time search as a popular post. Alongside it came a familiar companion theory: that the earthquake had been triggered by HAARP, a U.S. research facility in Alaska that has become a recurring villain in disaster-related conspiracy lore. Days later, as Japan somberly marked the anniversaries of the Hiroshima and Nagasaki atomic bombings and the end of World War II, public broadcaster NHK reported that a different but equally alarming strain of misinformation was gaining ground online: outright denial that the atomic bombings ever happened, or that they caused the horror and suffering that survivors have testified to for generations. Some posts on X and TikTok were drawing over a million views each, while a YouTube video claiming the bombing was a lie had attracted more than 300,000 views.
For experts who study the spread of false information, the shock was not simply that these claims existed—conspiracy theories are a global phenomenon—but that they were taking hold so quickly and so publicly in Japan, a nation often regarded as socially cohesive and highly resilient in the face of crisis. Yet the underlying human motivations are not difficult to understand. When a massive earthquake strikes, people feel powerless. The ground beneath them has betrayed their sense of safety, and they desperately want an explanation that restores the illusion of control. An “artificial explosion” or a secret military weapon may be terrifying, but at least it implies that someone, somewhere, caused the event. That narrative offers a strange comfort compared to the random, unfathomable violence of nature. Similarly, denying the atomic bombings can be a way of shielding oneself from an unbearable historical wound. Accepting that two nuclear devices incinerated entire cities and killed tens of thousands of civilians—and that the effects lingered in radiation sickness and social stigma for decades—requires confronting the darkest capacities of humanity. For some, especially those with little direct connection to survivors, it may feel easier to believe that such an atrocity was exaggerated, manipulated, or simply fabricated. These psychological impulses, amplified by digital platforms that reward outrage and spectacle, create a fertile ground for wildly improbable theories to flourish.
The Kumamoto earthquake conspiracy offers a vivid case study in how misinformation is manufactured and weaponized in real time. The claim about the “artificial explosion waveform” sounded convincing because it referenced actual scientific infrastructure and appeared immediately after a shocking event. But seismologists were quick to explain that the data showed nothing unusual. Earthquakes naturally produce complex waveforms, and a shallow offshore quake of magnitude 7.1 can easily appear abrupt and explosive in certain monitoring instruments. There was no evidence of a blast, no suspicious seismic pattern, and no plausible mechanism by which any human technology could simulate such a massive release of energy. The HAARP theory is even more fantastical: the facility in Alaska studies the ionosphere and does not have the capability to trigger tectonic shifts. Yet the theory persists because it has been recycled for decades, appearing after earthquakes in Turkey, Mexico, and Haiti, and it now enjoys a comfortable life in Japanese online communities, often accompanied by dramatic videos and pseudoscientific diagrams. The speed of the Kumamoto post’s spread was not accidental. It fit perfectly into the logic of social media algorithms, which prioritize engagement over accuracy. A post that promises forbidden knowledge, or that suggests authorities are hiding the truth, will always attract clicks, comments, and shares. The person who posted it likely experienced a surge of significance as their message traveled across the internet, becoming a temporary authority in a moment of collective fear.
The denial of the Hiroshima and Nagasaki bombings is a more complex phenomenon, rooted not in sudden panic but in the slow erosion of living memory. Japan’s hibakusha—atomic bomb survivors—once numbered in the hundreds of thousands. They bore witness to unspeakable horror and dedicated their lives to telling their stories so that no one else would ever suffer the same fate. But time has taken its toll. Many survivors have passed away, and those who remain are elderly. Younger generations no longer hear these testimonies firsthand; instead, they encounter the war through movies, documentaries, and online content, where revisionist narratives can be presented with equal or greater authority. NHK’s investigation found that some social media posts denied not only the bombings but also the scale of the casualties, questioning whether the United States really needed to use such weapons and suggesting that the Japanese government exaggerated the destruction for political reasons. These claims contradict an overwhelming body of evidence, including medical records, photographs, survivor accounts, and the observations of foreign journalists who visited the ruined cities. Yet in the fragmented digital environment, evidence is often less important than emotional resonance. A short video that tells a defiant story of national victimhood, or that frames the bombings as a hoax designed to shame Japan, can be deeply appealing to viewers who feel alienated from mainstream historical narratives. It offers them the pleasure of secret knowledge and moral outrage, wrapped in a simple and emotionally satisfying package.
Yuzuru Kido, a former deputy editor of J-CAST News and an internet media researcher who tracks Japanese social media discourse, captured the key difference between these two conspiracy strains. “Both the theory that the earthquake was artificially triggered and the denial of the atomic bombings lack scientific basis, but the contexts in which these conspiracy theories take root differ,” he told reporters. The earthquake theory thrives on disaster anxiety—the immediate, visceral fear of nature’s unpredictability and the suspicion that governments or militaries are using technology against ordinary people. The atomic bombing denial, by contrast, emerges from a longer, slower-burning crisis of historical memory. As the generation that lived through the war disappears, the space for memory is being filled with algorithmically optimized mythology. Kido’s distinction matters because it suggests that no single remedy will work for both. Debunking an earthquake conspiracy is primarily an exercise in science communication: explaining seismic data, restoring trust in official institutions, and helping people tolerate uncertainty during a frightening event. Combating history denial is a different challenge. It requires preserving and humanizing testimonies, making archival evidence accessible and emotionally compelling, and creating spaces where young people can question the past without being consumed by toxic narratives. But there is also a common thread. Both types of misinformation feed on distrust toward authority, a commodity in abundant supply in an age of institutional failures and unaccountable technology. People who feel ignored by elites, alienated from media, and anxious about the future are vulnerable to any story that gives them a target for their anger.
The broader danger of these conspiracy narratives is not merely that people will believe false things. It is that they will stop believing in the possibility of a shared, verifiable reality. In Japan, where earthquakes are a recurring fact of life, the spread of artificial explosion theories could have dire practical consequences. If citizens doubt official warnings and evacuation orders because they believe authorities are hiding the truth about disasters, they may fail to take life-saving actions. The same logic applies to history denial. If the atomic bombings become a debatable myth rather than a documented tragedy, then the moral lessons drawn from them—about the horrors of nuclear war, the value of peace, and the responsibility of nations—begin to crumble as well. Japan’s pacifism and its constitutional commitment to renouncing war have been deeply shaped by the memory of Hiroshima and Nagasaki. To erase that memory is not just to rewrite the past; it is to weaken the ethical foundations of the present. Misinformation experts say they are “shocked” because they recognize these stakes. They are witnessing, in real time, a quiet unraveling of the stories that helped hold Japanese society together for over seven decades. This is not a uniquely Japanese problem. Polarization, algorithmic amplification, and the erosion of trust in institutions are corroding public life around the world. But Japan has long considered itself an outlier, a nation where collective memory and social solidarity could withstand the chaos of the digital age. The rise of these twooutlandish claims is a reminder that no society is immune.
And yet, the response cannot be simple dismissal. Mockery and fact-checking alone will not win back the minds of people who have found meaning in conspiracy theories. To humanize the fight against misinformation is to recognize that the people who share these posts are not irrational monsters; they are frightened, lonely, and searching for order in a world that often feels patched together from contradictory fragments. They deserve honest explanations and visible compassion, not just corrections. Scientists and historians need to become storytellers, matching the emotional intensity of the conspiratorial narratives with stories that are equally powerful but grounded in truth. Media literacy must be taught not as a dry school subject but as a way of navigating life, helping people ask themselves why they believe what they believe and how a particular piece of content makes them feel. Survivors of the atomic bombings, whose voices are fading, should have their testimonies digitized, animated, and shared in formats that can compete with the slick falsehoods of TikTok. Community leaders, teachers, and religious figures all have roles to play in rebuilding a sense of shared reality. Above all, society must address the anxieties that give conspiracy theories their power: the fear of earthquakes, the fear of war, the fear of being deceived or forgotten. By strengthening social trust, acknowledging historical complexity, and offering genuine connection to people who feel left behind, it is possible to relieve the pressure that drives them toward fantasy. The work will take time, patience, and a willingness to listen. But in a country where the ground can shake without warning, and where the memory of unimaginable suffering is slipping away, this work is not optional. It is the quiet task of preserving both the physical and moral resilience of a nation—and of every citizen who must live with the uncertainty of the future.