1968 Hyūga-nada earthquake

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
1968 Hyūga-nada earthquake
1968 Hyūga-nada earthquake is located in Japan
1968 Hyūga-nada earthquake
UTC time1968-04-01 00:42:07
ISC event823387
Local dateApril 1, 1968 (1968-04-01)
Local time09:42:07
MagnitudeMw 7.5 [1]
Depth30 km [1]
Epicenter32°27′N 132°16′E / 32.45°N 132.27°E / 32.45; 132.27Coordinates: 32°27′N 132°16′E / 32.45°N 132.27°E / 32.45; 132.27 [1]
Areas affectedJapan

The 1968 Hyūga-nada earthquake (Japanese: 1968年日向灘地震) occurred on April 1 at 09:42 local time. The earthquake had a magnitude of Mw 7.5, and the epicenter was located in Hyūga-nada Sea, off the islands of Kyushu and Shikoku, Japan. The magnitude of this earthquake was also given as MJMA 7.5.[2] A tsunami was observed.[3] There were 15 people reported injured.[4] The intensity reached shindo 5 in Miyazaki and Kōchi.


This was an interplate earthquake between the Eurasian Plate and the Philippine Sea Plate. In this region, the Philippine Sea Plate is subducting beneath the Eurasian Plate. The subduction interface around this region include the Nankai Trough and the Ryukyu Trench.[5]

This earthquake is the strongest event recorded in the Hyūga-nada Sea region. The maximum slip was estimated to be 4 m.[6] It was estimated that, in the Hyūga-nada Sea region, earthquakes with magnitudes about 7.6 occur with a period of about 200 years, while earthquakes with magnitudes about 7.1 occur with a period of about 20 to 27 years.[7] It has been pointed out that there is a tendency of occurrence of inland earthquakes in Kyushu before and after large interplate earthquakes in the Hyūga-nada Sea region.[8]

See also[edit]


  1. ^ a b c ISC (19 January 2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre
  2. ^ Yagi, Yuji; Kikuchi, Masayuki (2003), "Partitioning between seismogenic and aseismic slip as highlighted from slow slip events in Hyuga-nada, Japan" (PDF), Geophysical Research Letters, 30 (2): 1087, Bibcode:2003GeoRL..30.1087Y, doi:10.1029/2002GL015664
  3. ^ Geist, Eric L (2002), "Complex earthquake rupture and local tsunamis" (PDF), Journal of Geophysical Research, 107 (B5): 2086, Bibcode:2002JGRB..107.2086G, doi:10.1029/2000JB000139
  4. ^ "高知県の地震活動の特徴 - 地震調査研究推進本部". www.jishin.go.jp.
  5. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2011-10-06. Retrieved 2011-04-02.CS1 maint: Archived copy as title (link)
  6. ^ "Refdoc". cat.inist.fr.
  7. ^ "日向灘". www.jishin.go.jp.
  8. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2011-07-20. Retrieved 2011-04-02.CS1 maint: Archived copy as title (link)

External links[edit]