1968 Tokachi earthquake

Geology

This earthquake was located near the junction of the Kuril Trench and the Japan Trench. It was an interplate earthquake. The focal mechanism of this earthquake showed movement on a thrust fault with a considerable slip-strike component. The sum of interplate seismic moment release by seismic and aseismic faulting in this earthquake was about 28×1020 N m. The 1960s was noted as one of the peak periods of interplate seismic moment release in the offshore Sanriku region.

Damage

Heavy rain occurred due to a low pressure system in the days leading up to the earthquake and aggravated the damage. In Hokkaido, building damage was reported. A four-story RC building of Hakodate University collapsed. In Aomori Prefecture, there was damage to railroads and highways in more than 200 places caused by collapses of artificial embankments. In Hachinohe, there was damage to buildings, water pipes, and gas pipes. The three-story building of Hachinohe Technical College suffered severe damage. The communication between Honshu and Hokkaido was cut off.

Tsunami

A tsunami was triggered by the earthquake, with a maximum height of about 6 m. An 11 cm high tsunami was recorded in Tahiti. In Japan, the tsunami caused flooding and damage to aquaculture.

References

References

1. National Geophysical Data Center / World Data Service (NGDC/WDS). (1972). "Significant Earthquake Database". [[National Geophysical Data Center]], [[National Oceanic and Atmospheric Administration.
2. "Tsunami forecast Archives".
3. (13 November 2003). "Crustal Deformation Model in Northeast Japan".
4. Kanamori, H.. (1971). "Focal Mechanism of the Tokachi-Oki Earthquake of May 16, 1968: Contortion of the Lithosphere at a Junction of Two Trenches". Tectonophysics.
5. "Space-time distribution of interplate moment release including slow earthquakes and the seismo-geodetic coupling in the Sanriku-oki region along the Japan trench" by I. Kawasaki, Y. Asai, and Y. Tamura
6. Masaya HIROSAWA. (16 December 1999). "DAMAGES TO BEAM-TO-COLUMN JOINT PANELS OF R/C BUILDINGS CAUSED BY THE 1995 HYOGO-KEN NANBU EARTHQUAKE AND THE ANALYSIS".
7. "Geomorphological Accidents Caused by the Tokachi-oki Earthquake" by K. Nishimura, S. Segawa, H. Mizuno, H. Hotta, O. Miura, T. Tamura, and T. Akagiri
8. Junji Kiyono. (19 September 2008). "Earthquake and lifeline damage".
9. "十勝沖地震 地震の概要". Bousai.pref.aomori.jp.
10. [[Headquarters for Earthquake Research Promotion. (22 August 2008). "三陸沖から房総沖にかけての地震活動の長期評価の一部改訂について （平成21年3月9日公表）".
11. (November 2014)
12. (September 4, 2009). "PAGER-CAT Earthquake Catalog". United States Geological Survey.