Japan issued a megaquake advisory on Tuesday after a magnitude 7.5 earthquake struck off the eastern coast of Aomori, the northernmost prefecture of Japan’s main island of Honshu, and just south of the northern island of Hokkaido. Damage from this quake was modest – 34 mostly mild injuries and some damage to roads and buildings.
Officials said the advisory was not a prediction and the probability of a magnitude 8 or larger quake is only about 1 per cent. But there’s hope the advisory will serve as a wake-up call for a quake that could have the devastation of the 2011 disaster that killed nearly 20,000 people and destroyed a nuclear plant.
There is an increased risk of a magnitude 8 or larger earthquake in the coming week. Officials are urging residents, especially along coastal areas, to be well prepared so they can grab an emergency bag and run as soon as possible if a bigger quake hits.
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Dozens hurt after magnitude 7.5 quake in northeastern Japan
Dozens hurt after magnitude 7.5 quake in northeastern Japan
This advisory seemed mindful compared with another advisory last year. The southern half of Japan’s Pacific coastline received a “Nankai Trough” megaquake advisory in the summer of 2024, but the ambiguity of that warning led to panic buying of emergency food, event cancellations and business closures.
The Japan Meteorological Agency (JMA) said that Monday’s powerful quake temporarily increased potential risks in the regions of Hokkaido and the Sanriku coast. That’s where the Pacific Plate beneath Japan forms the two trenches – the Japan Trench and Chishima Trench – that have caused many large quakes in the past.
Experts said the deadly quake and tsunami in 2011 was caused by movement associated with the Japan Trench. It spans from off the eastern coast of Chiba to Aomori, and the Chishima Trench goes from the eastern coast of Hokkaido to the northern islands and the Kurils.
In explaining the advisory, the JMA said the magnitude 9.0 quake on March 11, 2011, that devastated large swathes of Japan’s northern coast occurred two days after a magnitude 7.3 temblor that occurred at the Japan Trench off the eastern coast of Iwate, one of the hardest-hit areas in that disaster as well as in Monday’s quake.