| 岩手県沿岸北部地震 | |
 | |
  | |
| UTC time | 2008-07-23 15:26:19 |
|---|---|
| ISC event | 13389912 |
| USGS-ANSS | ComCat |
| Local date | July 24, 2008 |
| Local time | 00:26 (JST)[1] |
| Magnitude | 6.8 MJMA[1] 6.8 Mw[2] |
| Depth | 115 km (71 mi) |
| Epicenter | 39°48′07″N 141°27′50″E / 39.802°N 141.464°E[2] |
| Max. intensity | VII (Very strong) JMA 6− [3] |
| Casualties | 1 dead, 211 injured[4] |
The July 2008 Iwate earthquake (岩手県沿岸北部地震, Iwate-ken Engan Hokubu Jishin) was an earthquake that occurred in Iwate Prefecture, Japan on July 23, 2008. The earthquake's moment magnitude was 6.8 and it occurred at a depth of 115 km. Since this earthquake was an intermediate-focus earthquake, the shaking of the earthquake was observed over a wide range.[5] It had a maximum JMA intensity of Shindo 6− (Aomori and Iwate).[3]
The earthquake ruptured a fault within the subducting Pacific Plate beneath northern Iwate at a calculated depth of 115 km (71 mi). Earthquakes within the subducting slabs are intraslab events; other intraslab earthquakes including those occurring in 1987, 1993, 2001 and 2003 have been damaging. Although occurring deeper in Earth's interior, these events can produce large ground motions. In the case of this earthquake, the recorded peak ground acceleration exceeded 1,000 cm/sec2, corresponding to IX (Violent) on the Mercalli intensity scale. A seismic inversion study suggest the earthquake ruptured two fault segments; the northern segment measuring 14 km (8.7 mi) × 30 km (19 mi), and the southern segment measuring 16 km (9.9 mi) × 30 km (19 mi). A maximum slip of 2.4 m (7 ft 10 in) was estimated.[6]
The earthquake left one person dead; an elderly woman in Iwaki who suffered severe wounds after falling from her bed due to the shaking. At least 211 others were also injured.[7]