"Major Earthquake in Japan Seems Imminent"... Growing Fear of 'Nankai Earthquake' Across the Archipelago

Magnitude 7.1 Earthquake Off Miyazaki Prefecture
Tsunami Advisory Issued Following Tsunami Observations
Investigation Into Possible Link to Magnitude 9 Nankai Earthquake

The Japan Meteorological Agency announced on the afternoon of the 8th that a magnitude 7.1 earthquake occurred off the coast of Miyazaki Prefecture in southeastern Kyushu, Japan. The Japanese government is investigating the connection between this earthquake and the 'Nankai Trough megathrust earthquake,' which occurs at intervals of 100 to 150 years.

Citizens are evacuating buildings after an earthquake occurred in Miyazaki Prefecture, Kyushu, Japan. [Image source=AP Yonhap News]

Due to this earthquake, a seismic intensity of lower 6 on the Japan Meteorological Agency scale was detected in some areas of Miyazaki Prefecture. A seismic intensity of lower 6 means it is difficult for people to stand, wall tiles and window glass break, and bookshelves topple. Unlike magnitude, which indicates absolute strength, the seismic intensity measured by the Japan Meteorological Agency represents the perceived shaking by residents and the degree of movement of surrounding objects, expressed numerically on a scale from 0 to 7.

On the same day, a tsunami advisory was issued for Miyazaki Prefecture, Oita Prefecture, and other areas in Kyushu. This was due to tsunamis observed up to approximately 50 cm in some parts of Kyushu and Shikoku. A tsunami advisory is issued when the expected tsunami height is between 0.2 and 1.0 meters, while a tsunami warning is issued when the height is between 1 and 3 meters.

A magnitude 7.1 earthquake occurred on the afternoon of the 8th off the coast of Miyazaki Prefecture in southeastern Kyushu, Japan. [Source: Japan Meteorological Agency] [Image source: Yonhap News]

The Japanese government is investigating the relationship between this earthquake and the 'Nankai megathrust earthquake.' This is because the epicenter of this earthquake lies within the expected range where a Nankai Trough earthquake could occur. The Nankai megathrust earthquake occurs at intervals of 100 to 150 years. The Nankai Trough extends from the offshore area of Shizuoka Prefecture, west of the Tokyo metropolitan area, to the southern sea area of Shikoku.

The Japanese government estimates the probability of a Nankai earthquake occurring within the next 30 years to be 70 to 80%. This earthquake, expected to be of magnitude 8 to 9, is projected to cause approximately 230,000 deaths and missing persons if it occurs.

Meanwhile, Japanese media NHK reported that injuries occurred in some areas, with patients being transported to hospitals and water pipes damaged.

However, according to Kyodo News, no abnormalities were detected at the Sendai Nuclear Power Plant in Kagoshima Prefecture or the Ikata Nuclear Power Plant in Ehime Prefecture near the epicenter. Shortly after the earthquake, the Kyushu region's high-speed train, the Shinkansen, temporarily suspended operations but resumed service around 5:25 p.m..

Hayashi Yoshimasa, Chief Cabinet Secretary and spokesperson for the Japanese government, stated at an emergency press conference, "We are confirming human and material damage," and added, "We will respond to the disaster in cooperation with local governments, focusing on the police, fire and disaster management forces, and the Japan Coast Guard."