1968 Tokachi earthquake explained

1968 Tokachi earthquake
Timestamp:1968-05-16 00:49:02
Isc-Event:821946
Anss-Url:iscgem821946
Local-Time:09:49:02
Magnitude:8.3
Depth:26km (16miles)
Location:40.9°N 143.35°W
Type:Oblique-slip
Countries Affected:Japan
Tsunami:6m (20feet)
Aftershocks:7.9 May 16 at 20:39
Intensity:

Casualties:47–52 killed
281–330 injured

The 1968 Tokachi earthquake (1968年十勝沖地震 Sen-kyūhyaku-rokujūhachi-nen Tokachi-oki Jishin) occurred on May 16 at 0:49 UTC (09:49 local time) in the area offshore of Aomori and Hokkaido. The magnitude of this earthquake was put at 8.3. The intensity of the earthquake reached shindo 5 in Aomori, Aomori and Hakodate, Hokkaido.[1]

Geology

This earthquake was located near the junction of the Kuril Trench and the Japan Trench. It was an interplate earthquake.[2] 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.[3]

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.[4] 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.[5] The communication between Honshu and Hokkaido was cut off.[6]

Tsunami

A tsunami was triggered by the earthquake,[7] with a maximum height of about 6m (20feet).[8] An 11sp=usNaNsp=us high tsunami was recorded in Tahiti.[9] In Japan, the tsunami caused flooding and damage to aquaculture.

See also

Notes and References

  1. Web site: Tsunami forecast Archives . 2012-04-09 . 2013-10-29 . https://web.archive.org/web/20131029224634/http://www.hiroi.iii.u-tokyo.ac.jp/index-genzai_no_sigoto-tunami_joho-archives.pdf . dead .
  2. Web site: Crustal Deformation Model in Northeast Japan. 13 November 2003. Hisashi Suito. Mikio Iizuka. Kazuro Hirahara. 2014-09-12. https://web.archive.org/web/20150301060337/http://aces.org.au/ACES-2002-workshop/PDF/page333-340.pdf. 2015-03-01. dead.
  3. "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
  4. Web site: DAMAGES TO BEAM-TO-COLUMN JOINT PANELS OF R/C BUILDINGS CAUSED BY THE 1995 HYOGO-KEN NANBU EARTHQUAKE AND THE ANALYSIS. 16 December 1999. Masaya HIROSAWA. Tomoaki AKIYAMA. Tatsuya KONDO. Jiandong ZHOU. amp. 2014-09-12.
  5. "Geomorphological Accidents Caused by the Tokachi-oki Earthquake" by K. Nishimura, S. Segawa, H. Mizuno, H. Hotta, O. Miura, T. Tamura, and T. Akagiri
  6. Web site: Earthquake and lifeline damage. 19 September 2008. Junji Kiyono. 2014-09-12. https://web.archive.org/web/20130612072739/http://danso.env.nagoya-u.ac.jp/jsafr/documents/AFR028_095_106.pdf. 2013-06-12. dead.
  7. Web site: 十勝沖地震 地震の概要. Bousai.pref.aomori.jp. 2014-09-12. https://web.archive.org/web/20150923194042/http://www.bousai.pref.aomori.jp/jisinsouran/tokachi/1_jisin_target.htm. 2015-09-23. dead.
  8. Web site: 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). 22 August 2008. 地震調査研究推進本部 地震調査委員会. 2014-09-12.
  9. http://ioc3.unesco.org/itic/files.php?action=dlfile&fid=202&PHPSESSID=48e5d48744083035c312f673159c7a90