2004 Chūetsu earthquake
| 新潟県中越地震 | |
Collapsed houses in Nagaoka City | |
| UTC time | 2004-10-23 08:56:00 |
|---|---|
| ISC event | 7421058 |
| USGS-ANSS | ComCat |
| Local date | October 23, 2004 |
| Local time | 17:56:00 JST (UTC+9) |
| Magnitude | MJMA 6.8 Mw 6.6 |
| Depth | 13 km (8.1 mi) |
| Fault | Muikamachi fault |
| Type | Reverse |
| Areas affected | Niigata, Fukushima, Gunma, Nagano and Saitama Prefectures, Japan |
| Total damage | US$40 billion ((equivalent to $68.2 billion in 2025) |
| Max. intensity | JMA 7 (MMI IX) |
| Peak acceleration | 2.56 g |
| Landslides | 442+ |
| Aftershocks | 825+ recorded (as of 30/11/2004) MJMA 6.5 on 23 October 2004 (strongest) |
| Casualties | 68 fatalities, 4,805 injuries |
The Chūetsu earthquake (中越地震, Chūetsu jishin) occurred in Niigata Prefecture, Japan, at 17:56:00 JST (08:56:00 UTC) on 23 October 2004. The Japan Meteorological Agency (JMA) officially named it the "Heisei 16 Niigata Prefecture Chūetsu Earthquake" (平成16年新潟県中越地震, Heisei ju-roku-nen Niigata-ken Chuetsu Jishin). The reverse-faulting shock achieved a maximum JMA seismic intensity of Shindo 7 and Modified Mercalli intensity of XI–XII (Extreme). It caused widespread destruction and casualties in Niigata Prefecture, while also causing damage and injuries in Fukushima, Gunma, Saitama and Nagano Prefectures.
At least 68 people were killed, of which 52 were disaster-related deaths aggravated by illnesses and stress attributed to the earthquake and its effects. More than 131,600 houses were damaged in four prefectures, of which 17,700 partially or fully collapsed. It caused economic losses of US$40 billion, which made it the second costliest natural disaster in history at the time.