1964 Niigata earthquake
 Effects of soil liquefaction caused by the earthquake on apartment buildings in Niigata | |
  | |
| UTC time | 1964-06-16 04:01:43 |
|---|---|
| ISC event | 866844 |
| USGS-ANSS | ComCat |
| Local date | 16 June 1964 |
| Local time | 13:01:43 |
| Magnitude | 7.6 Mw |
| Depth | 34 km (21.1 mi) |
| Epicenter | 38°22′N 139°13′E / 38.37°N 139.22°E |
| Type | Dip-slip |
| Areas affected | Japan, Niigata Prefecture |
| Max. intensity | MMI VIII (Severe)[1] |
| Tsunami | yes |
| Casualties | 36 dead or missing (385 injured)[2] |
The 1964 Niigata earthquake (
Geology
The northwestern side of Honshu lies on the
Damage
There were 3,534 houses destroyed and a further 11,000 were damaged.
Fire and liquefaction
Niigata City, which had just recovered from the Great Niigata Fire of 1955, sustained considerable damage from fire and liquefaction that resulted from the earthquake. Aside from the buildings destroyed by liquefaction on the left bank of the Shinano River, there was also extensive damage on the right bank. The runway of the Niigata Airport, which was near the hypocenter, was flooded due to liquefaction and the tsunami; and a fire broke out inside the airport. Most devastatingly, the pipes of a gasoline tank owned by Showa Shell Sekiyu, located between the airport and the harbor, were also damaged by the shaking. Gasoline from the tank was brought to the sea surface by the tsunami and underground water released by the liquefaction, and ignited five hours after the earthquake. The fire spread to nearby tanks and induced explosions that fed the fire, allowing it to continue for 12 days. The fire spread to nearby residential areas, leaving 1407 people displaced.[5] This fire is said to be the worst industrial complex fire in the country's history. At the time the cause of the fire was said to be caused by the liquefaction, but later research into large earthquakes revealed that long period ground motion also played a role.
At the time of the fire, the new specially-designed fire truck for fighting chemical fires had not yet been deployed to Niigata City. A request was sent to the Fire and Disaster Management Agency and troops were dispatched from the Tokyo division. There was a danger of the fire spreading to an attached oxygen tank, but the troops from Tokyo managed to stop it from spreading to the tank, after a 20-hour battle.
Showa bridge
The collapse of the Showa bridge in Niigata has been analysed in detail.[6][7] From eyewitness reports it appears that failure began 70 seconds after the start of the earthquake, suggesting that ground motion was not responsible. Movement of piles beneath the bridge piers, due to lateral spreading caused by liquefaction, is regarded as the main cause of the failure.[6][7]
Characteristics
Earthquake
The earthquake had a
Tsunami
The first wave of the tsunami hit Niigata City approximately 15 minutes after the earthquake. It caused flooding damage on Sado Island, Awa Island, and as far away as the Oki Islands in Shimane Prefecture. The wave reached heights of 3 m at Ryōtsu Harbor, 4 m at Shiotani and near Iwafune Harbor, and between 1 and 2 m at Naoetsu. It was also reported that due to the run-up that occurs on sandy beaches, the wave reached 6 m in some places.[10] The first wave was the highest in many places, but the third was reportedly higher in others. The ensuing waves came at intervals of 20 and 50 minutes.[11] Flooding caused by the tsunami persisted in some areas for up to a month.
Vestiges
 |
Due to urbanization and modernization in Niigata City and the surrounding area, water pumping quickly increased in 1950, in order to extract water-soluble natural gas in the groundwater. As a result, land subsidence became a serious problem. Since 1959, due to restrictions on the extractions of natural gas and groundwater in the Niigata city area, large-scale land subsidence has lessened. However, in that period the ground was observed to settle an average of 20 cm per year. This land subsidence, the liquefaction in the inner city, and the tsunami all contributed to the massive inundation damage during the earthquake.
The Bandai Bridge, one of the commuter bridges spanning the Shinano River in the city, survived the earthquake intact, but not unscathed. The streets that cross under the bridge on each side and run parallel to the river are approximately 1 meter different in elevation. The bridge itself only sank about 10 cm during the earthquake, but coupled with the aforementioned land subsidence it has sunk a total of 1.2 meters.
New laws concerning earthquake insurance were enacted in June 1966 in response to this earthquake.
See also
References
- ^ "M 7.6 – 24 km NW of Murakami, Japan – Impact". earthquake.usgs.gov. United States Geological Survey. Retrieved 18 November 2021.
- ^ a b c USGS. "Historic Earthquakes – Niigata, Japan 1964 June 16 04:01 UTC Magnitude 7.5". Archived from the original on 28 January 2010. Retrieved 10 June 2010.
- ISSN 0370-9868.
- ^ a b c d Kawasumi, H. (1968). "1. Introduction" (PDF). In Kawasumi H. (ed.). General Report on the Niigata Earthquake of 1964. Tokyo, Japan: Tokyo Electrical Engineering College Press. Archived (PDF) from the original on 4 June 2010. Retrieved 10 June 2010.
- ^ 津波 ディジタルライブラリィ[permanent dead link] 津波ディジタルライブラリィ作成委員会
- ^ . Retrieved 10 June 2010.
- ^ ISBN 978-3-540-79846-0.
- doi:10.1016/0031-9201(83)90099-7. Archived from the original(PDF) on 23 July 2010. Retrieved 10 June 2010.
- .
- doi:10.7289/V5PN93H7. Retrieved 22 March 2024.
- ^ 昭和39年6月16日新潟地震調査概報 (新潟地震による津波) 東京大学地震研究所 地震研究所研究速報. 第8号, 1964-09, pp. 58–62
External links
- The International Seismological Centre has a bibliography and/or authoritative data for this event.