A Japan earthquake magnitude scale has fallen from its highest level in the 1990s and the latest estimate suggests it will be the lowest ever recorded in the world.
The quake, which struck at 6:23am local time (8:23pm GMT) on Tuesday, was the worst to hit Japan since a devastating tsunami in 2011.
The magnitude 9.2 quake struck just south of the capital, Tokyo, in the main island of Kyushu, and was felt as far away as central Osaka.
The scale was used by Japanese authorities to monitor how dangerous earthquakes were before they were felt.
Its value was revised from 6.3 to 6.2, down from the previous 6.4.
It is the highest magnitude since at least the early 1990s, when the scale was 6.1.
Japan’s National Meteorological Agency said on Wednesday that the quake, the worst since the 2011 tsunami, was felt across most of the country and as far north as Hokkaido.
The US Geological Survey said on Thursday that it had recorded the strongest earthquake in more than two decades, and the US Geological Institute had recorded three other strong quakes in the past three years.
The United States Geological Survey has recorded at least three powerful earthquakes this year, while Japan has recorded four.
Japan is due to conduct its third nuclear test this week amid concerns over North Korea’s possible atomic weapons programme.
The country has also suffered several earthquakes this month.