As a result, Fukuoka has been the window of east Asian culture flowing into Japan since ancient times, and now there are many direct routes to Korea, mainland China and Taiwan.

The strong earthquake occurred at 10:53 am in the Kyushu region, about 70 km west of Shimonoseki city in Yamaguchi prefecture.

The earthquake occurred on Sunday, March 20, 2005, which was also a public holiday known as Vernal Equinox Day, falling in the middle of a three-day weekend.

It was also approximately 9 kilometers north-northwest of Nishiura Cape at the northern tip of Itoshima Peninsula.

Suppose that an earthquake had occurred along the Kego fault within the last 2000 years, the risk would be unchanged.

[14] The focal mechanism involved a strike-slip fault with a pressure axis oriented in an east–west direction.

[21] Additionally, a small aftershock zone became active near the sea around Midou Peninsula a day after the main earthquake, starting from March 21.

[29] Despite this, the northwest coast of northern Kyushu, along the Genkai Sea, is relatively inactive in terms of seismic activity compared to other regions in Japan.

Subsequent seafloor surveys after the earthquake did not reveal any evidence of faulting in the epicentral area.

It's believed that slip along strike-slip faults may not produce visible offsets on the seafloor, making them difficult to detect.

[33] Between the occurrence of the main earthquake and the end of June 2005, there were 375 aftershocks with a seismic intensity of 1 or higher recorded over a period of just over three months.

Within half a year the size of aftershocks continued, a total of several thousand times, but the overall trend gradually reduced.

However, this does not include seismic intensity data from Genkai Island until 6:00 PM on March 21 when the seismometers were installed.

[37] An aftershock hit at 6:11 a.m. April 20 on Japan's southern main island of Kyūshū, the Central Meteorological Agency reported.

2 and 56 people were severely and slightly injured and treated at a hospital in Fukuoka due to the quake.

During this earthquake, more than half of the 225 residential buildings on the Genkai Island in the western part of Fukuoka city, near the epicenter, suffered serious damage.

The island was particularly hard hit because it near to the quake and traditional Japanese homes are less vulnerable to earthquakes than "mansions" that are built by engineers.

Traditional Japanese houses, particularly in the areas of Daimyō and Imaizumi, were the most heavily damaged and many were marked for demolition.

More than half of the 225 residential buildings on the Genkai Island in the western part of Fukuoka city, near the epicenter, suffered serious damage According to public broadcaster NHK, local rail services were suspended after the tremors triggered an automatic safety mechanism.

Telephone service in the southern prefecture was jammed after an automatic safety mechanism was triggered by the tremors.

The meteorological agency issued a tsunami warning after the strong earthquake, but lifted it at noon.