  | |
| UTC time | 2011-04-11 08:16:12 |
|---|---|
| ISC event | 16416735 |
| USGS-ANSS | ComCat |
| Local date | 11 April 2011 |
| Local time | 17:16 JST |
| Magnitude | 6.6 Mw[1] |
| Depth | 13 km (8 mi) |
| Epicenter | 37°00′04″N 140°24′04″E / 37.001°N 140.401°E[1] |
| Type | Dip-slip |
| Areas affected | Japan |
| Max. intensity | MMI VIII (Severe) JMA 6− |
| Peak acceleration | 2.11 g 2071.7 Gal |
| Tsunami | No |
| Landslides | Yes |
| Casualties | 4 dead, 10 injured |
A potent magnitude 6.6 Mw intraplate aftershock occurred at 17:16 JST (08:16 UTC) on 11 April, in the Hamadōri region of Fukushima, Japan. With a shallow focus of 13 km (8.1 mi), the earthquake was centred inland about 36 km (22 mi) west of Iwaki, causing widespread strong to locally severe shaking. It was one of many aftershocks to follow the 11 March Tōhoku earthquake, and the strongest to have its epicentre located inland.
The earthquake occurred as a result of normal faulting to the west of Iwaki, and triggered numerous landslides across adjacent mountainous areas. A few fires broke out, and 220,000 households lost electricity. Officials issued localised tsunami alerts, though no significant waves were generated. The earthquake caused little structural damage, but killed four people and injured ten others. The strong ground movements triggered the reactivation of a nearby geological fault, prompting researchers to conduct extensive surveys in the region.
- ^ a b "M6.6 – eastern Honshu, Japan (BETA) 2011-04-11 08:16:12 UTC". United States Geological Survey. 11 April 2011. Archived from the original on 2022-05-09. Retrieved 2014-06-07.