On the afternoon of July 3, 2025, at precisely 4:13 PM, a significant seismic event rattled the Tokara Islands, located in Kagoshima Prefecture, Japan. The Japan Meteorological Agency (JMA) confirmed a magnitude 5.5 earthquake struck the region, marking a momentous occasion as the first time since the modern observation system was established in 1994 that the area experienced a seismic intensity of 6- (six minus). This level of shaking, recorded on Akusekijima Island, made standing difficult and caused damage such as broken wall tiles, shattered window glass, and toppled bookshelves. The quake's depth was measured at 20 kilometers beneath the sea floor, and fortunately, the JMA assured there was no tsunami threat.
The Tokara Islands, a cluster of seven inhabited and five uninhabited islands south of Kyushu, have been the epicenter of an intense earthquake swarm since late June 2025. Over the past two weeks, more than 1,000 small-scale tremors have been recorded, with at least 11 strong earthquakes of magnitude 5.0 or higher occurring since June 22. Notably, six of these stronger quakes happened just on July 2 and 3, including a magnitude 5.6 quake on July 2 that caused a seismic intensity of 5- (five minus), frightening residents and rattling household items.
Japanese Chief Cabinet Secretary Yoshimasa Hayashi reassured the public during a press conference, stating, "We have received reports confirming that all residents are safe," and emphasized there were no requests for Self-Defense Forces deployment nor any reported material damages. Despite the intensity and frequency of these tremors, the government remains vigilant but calm.
Seismic intensity, or "Shindo" as measured in Japan, differs from magnitude. While magnitude reflects the earthquake's absolute energy release, Shindo gauges how strongly the quake is felt at specific locations, considering human perception and object movement. The highest Shindo level is 7, making the 6- intensity on Akusekijima particularly noteworthy for its potential to cause significant disruption.
Experts analyzing the ongoing seismicity suggest that multiple fault segments are likely influencing the surge in earthquake activity. Professor Hisayoshi Yokose of Kumamoto University highlighted that, unlike previous earthquake swarms in December 2021 and September 2023—which involved two fault segments—this current episode might be impacted by three distinct faults. Such complexity could explain the sheer volume of tremors, which reached over 1,050 with a Shindo of 1 or higher between June 21 and the evening of July 3.
The timing of these seismic events has stirred public anxiety, particularly due to a popular manga artist, Tatsuki Ryuu, who gained notoriety for predicting the 2011 Great East Japan Earthquake. In his 2021 manga "My Future Seen," Ryuu depicted a catastrophic underwater volcanic eruption and tsunami occurring in July 2025. This fictional prediction has fueled rumors of an impending major earthquake, especially as the date of July 5, 2025, approaches. The recent flurry of strong earthquakes in the Tokara Islands has only intensified these fears.
However, the Japan Meteorological Agency remains firm in its stance that current scientific knowledge does not allow for precise earthquake predictions. A JMA official emphasized, "While the Nankai Trough earthquake has an 80% probability of occurring within the next 30 years, there is likely no connection between it and the Tokara Islands earthquakes." The agency also dismissed the rumors of a major earthquake in July 2025 as baseless, stating, "Earthquake prediction requires specifying when, where, and with what magnitude, and current technology cannot achieve this. The major earthquake rumors are unfounded."
The widespread concern has had tangible effects beyond Japan’s borders. In May 2025, the number of visitors from Hong Kong to Japan dropped by 11.2% compared to the previous year, making Hong Kong the only major region to show a decline in tourism to Japan during that period. Additionally, Hong Kong Greater Bay Airlines announced it would suspend flights connecting Hong Kong with Japan's Tottori and Tokushima prefectures starting September 1, 2025, citing the earthquake rumors as a contributing factor.
Despite the swirling speculation, the JMA urges continued vigilance and preparedness amid the ongoing seismic activity. They caution that it remains unclear when the earthquake swarm will subside, advising residents and authorities alike to remain alert for the possibility of further strong tremors.
Historically, the Tokara Islands have experienced similar swarms, with over 300 small earthquakes occurring both in December 2021 and September 2023. The current episode's uniqueness lies in the unprecedented seismic intensity and the involvement of multiple fault lines, underscoring the region's complex tectonic setting.
As July 5 approaches, with its ominous association in popular culture, scientists and officials continue to monitor the situation closely. While the public grapples with anxiety fueled by manga predictions and media reports, experts remind us that science does not support deterministic forecasts of earthquakes. Instead, the focus remains on preparedness, resilience, and clear communication to mitigate risks in this seismically active part of Japan.
