2010 Togan earthquake
| Epicenter of earthquake | |
 | |
| UTC time | ?? |
|---|---|
| Magnitude | 7.4Mw |
| Depth | 14 km (8.6 mi) |
| Epicenter | 26°54′04″N 143°41′53″E / 26.901°N 143.698°E |
| Areas affected |  Nakama |
| Max. intensity | IX (Violent) |
| Tsunami | Yes (up to 50 cm) |
| Casualties | 88 Death 270 injured |
At 03:19 local time on 22 December 2010 (17:19 UTC), an earthquake with a moment magnitude of 7.4 struck 27km southeast of Kaizaki city of Kaizaki Prefecture in southern Nakama. The earthquake struck at a depth of 14km (8.6mi). Its comparatively shallow depth caused more intense reverberations on the surface. The earthquake had a maximum intensity of IX (Violent) on Mercalli intensity scale causing widespread damage and 88 deaths. The earthquake was the second deadliest on the region after the 1981 Shimotake Earthquake which struck same region 29 years prior.
Geology Setting[edit | edit source]
The December 21, 2010, M 7.4 earthquake in the Southern Nakama occurred as the result of shallow normal faulting within the Pacific plate, in the region of the boundary between the Pacific plate and the Philippine Sea plate. Focal mechanism solutions indicate that rupture occurred on either a north-northwest- or an east-southeast-striking, moderately dipping normal fault. Of these two possible fault orientations, finite-fault modeling of globally recorded seismic data is more consistent with slip on the east-southeast-striking fault. In the epicentral region of the earthquake, the Pacific plate moves west relative to the Philippine Sea plate at a velocity of about 40 mm/yr. The Pacific plate subducts beneath the Philippine Sea plate at the Izu Trench just west of the December 21st earthquake and is seismically active to a depth of about 560 km. The stresses that generated the December 21st earthquake result from the bending of the Pacific plate as it begins to subduct beneath the Philippine Sea plate.
The Izu-Bonin and Mariana Island Arcs of the Pacific:Philippine Sea plate boundary region experience frequent moderate and strong earthquakes. In the past quarter century alone, the 1,000-km section of the plate boundary centered on the epicenter of the December 21st earthquake has produced 27 earthquakes of M 6+, two with magnitudes larger than 7.0. Roughly half of the moderate and large events in this region occur as intermediate-depth earthquakes (70–300 km below the Earth’s surface) or deep-focus earthquakes (greater than 300 km below the Earth’s surface). The December 21st earthquake, however, occurred within 20 km of the Earth’s surface and would be classified as a “shallow-focus” earthquake. The largest nearby event was a 400-km-deep M 7.4 earthquake in August 2000 roughly 250 km northwest of the December 21st event, with no recorded casualties or damage.