The Northern Tango Earthquake (北丹後地震)

The earthquake in the northern Tango Province occurred at 6:27:39 pm on March 7, 1927. The epicenter of seismic activity for the quake was in the northern Tango Peninsula, Kyoto Prefecture, at the latitude of 35 degrees, 37.9 minutes north, and the longitude of 134 degrees, 55.8 degrees east. It was a strong earthquake with a magnitude of 7.3 on the Richter scale. In the northern Tango Province, Toyooka-cho (now Toyooka City), Miyazu-cho (now Miyazu City) and Mineyama-cho (now Kyotango City) all registered a magnitude of 6 on the Richter scale. Kyoto City, Sumoto City (Hyogo Prefecture), Fukui City (Fukui Prefecture), Tsuruga City, Nara City (Nara Prefecture) and Fukuyama City (Hiroshima Prefecture) all registered a magnitude of 5 on the Richter scale.

Damage

The earthquake devastated the northern Kansai region, as well as the Chugoku region and the Shikoku region. The area of about 15km at the base of the Tango Peninsula was hit especially hard. In Amino-cho, Kaya-cho, Iwataki-cho and Mineyama-cho, where the damage was particularly severe, the ratio of collapsed buildings reached 70%~90%. As the earthquake occurred at a time when many people were cooking dinner, fires spread in the area. The large-scale fires spread especially in Amino-cho, Mineyama-cho and Nodagawa-cho, and 8,287 households in total were burned down. The quake struck Mineyama-cho, famous for its "Tango-chirimen crepe," the hardest. 97% of buildings including the textile factories were burned down in Mineyama-cho. The mortality rate reached 22% of its population.

The damage by the quake extended across a large area, including Kinosaki-cho, which had suffered severe damage in the Northern Tajima Earthquake 2 years previously and once again 2,300 households or more were lost to fire in the Northern Tango Earthquake. Even in Yonago City in Tottori Prefecture, 150km away from the epicenter, 2 houses collapsed. In Osaka City, cracks in the ground spewed mud water and flooded houses. It is thought that this was caused by ground liquefaction. The statistics for the damage, which show the extent of the catastrophe, are as follows: 2,925 deaths (2,898 deaths in Kyoto City); 7,806 injuries; 12,584 homes destroyed; 9,443 homes partially destroyed; 8,287 homes burned to the ground; 6,459 homes burned; 96 homes partially burned.

Two Faults

The Northern Tango Earthquake revealed two earthquake faults on the surface. They are the 'Goson Fault' (approximately 18km long), which extends from Asamogawa, Amino-cho to Mie District, Omiya-cho (Kyoto Prefecture), and the 'Yamada Fault' (approximately 7km long), which extends from Iwaya District, Nodagawa-cho to Fuchu District, Miyazu City. The Goson Fault was raised a maximum of 80cm on the west side and moved 270cm towards the south. The Yamada Fault was raised a maximum of 70cm on the north side and moved 80cm towards the east. The Goson Fault was designated as a national natural treasure on December 17, 1929, and today it can be observed at three spots where it is preserved.

Others

The victims of the quake lost their homes during the extremely cold snow season, and media such as newspapers held campaigns to support the victims and to collect money for them. The distribution and the initial motion of the seismic wave as well as the movement in the Earth's crust was clearly observed during the Northern Tango Earthquake; and as a result, the field of seismology has greatly developed since.