Japan issues first of its kind megaquake advisory, asks people to prepare for worst

Japan has sent out a first of its kind “megaquake” advisory, prompted by the 7.1-magnitude earthquake off the southern coast of the country on Thursday, which injured 14 people.

In light of the advisory, panic has spread, with people rushing to hoard supplies and seek safety shelters, AFP reported. Even the Japanese Prime Minister, Fumio Kishida, cancelled his four-day trip to Central Asia after the alert was sounded.

“As the prime minister with the highest responsibility for crisis management, I decided I should stay in Japan for at least a week,” Kishida told reporters.

AFP reported that bullet trains between cities are running at lower speeds and nuclear plants around the country have also been instructed to double-check their disaster preparations.

The earthquake in question is considered a once-in-a-century phenomenon and, if it occurs, can trigger tsunamis too.

WHAT IS THE ADVISORY?

Firstly, scientists can’t predict earthquakes. Over the years, with the right equipment, however, they have learnt to make accurate forecasts about higher risk periods of when one might hit.

“The likelihood of a new major earthquake is higher than normal, but this is not an indication that a major earthquake will definitely occur,” the Japan Meteorological Agency (JMA) said.

Regardless, residents have been asked to prepare for the worst, to review evacuation routes, and be attentive to any other warning that might come.

THE FEARED QUAKE

Japan geographically sits atop the Ring of Fire, causing the country to experience around 1,500 earthquakes a year, although most of them are mere tremors and harmless.

This one might be different.

The advisory pertains to the Nanakai Trough ‘subduction zone’ between two tectonic plates in the Pacific Ocean. In technical terms, subduction zone faults build stress over time and a megaquake occurs when one of those faults slips and releases that stress. Scientists believe it can cause an earthquake of a magnitude more than nine.

Japanese warning guidelines say that the probability a large earthquake will follow a magnitude-7 within a week is roughly “once per a few hundred times”, according to a study last year. Although the probability is high enough to warrant an advisory, it is entirely possible that the recent tremors will not trigger a megaquake.

According to AFP, the central government had predicted in 2022 that an earthquake of that scale would hit in the next 30 years with a rough 70 per cent probability. Experts believe a quake of this scale will result in the loss of thousands of lives and trillions in damage – a frightening prospect.