February 8, 2008
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion
* On January 26, there was a M4.8 earthquake at a depth of approximately 10km in the Noto region, Ishikawa prefecture. This earthquake had a maximum seismic intensity 5 Lower. This event is an aftershock of the Noto Hanto Earthquake in 2007. to supplementary reports
* On January 13, there was a M4.1 earthquake at a depth of approximately 10km in northern Oshima subprefecture. to supplementary reports
* On January 11, there was a M4.7 earthquake at a depth of approximately 50km off-shore of Iwate prefecture. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This event occurred at the boundary between the Pacific and the continental plates. to supplementary reports
* On January 26, there was a M4.8 earthquake at a depth of approximately 10km in the Noto region, Ishikawa prefecture. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This earthquake is an aftershock of the Noto Hanto Earthquake in 2007.
* There have been no anomalous changes observed in the GPS data for the Tokai region. to supplementary reports
* There was no remarkable activity. to supplementary reports
* There was no remarkable activity. to supplementary reports
February 8, 2008
The following are the numbers of earthquakes by magnitude that occurred in Japan and the surrounding area during January 2008.
(reference)
The following regions have been noted as having major seismic activity during the period from January 2007 to the end of December 2007.
| - Off-shore east of the Chishima Islands | M8.2 on January 13, 2007 | |
| - Noto Hanto Earthquake | M6.9 on March 25, 2007 (depth approximately 10km) | |
| - Central Mie prefecture | M5.4 on April 15, 2007 (depth approximately 15km) | |
| - Off-shore northwest of Miyakojima | seismic activity with M6.3, M6.7 and M6.1 on April 20, 2007 | |
| - Niigataken Chuetsu-oki Earthquake in 2007 | M6.8 on July 16, 2007 (depth approximately 10km) | |
| - Off-shore west of Sakhalin | M6.4 on August 2, 2007 | |
| - Near the coastal area of Kujukurihama | seismic activity with M5.3 on August 16, and M4.8 on August 18, 2007 | |
| - Coast of Peru | M8.0 on August 16, 2007 | |
| -Western Kanagawa prefecture | M4.9 on October 1, 2007 (depth approximately 15km) |
There is no supplementary information for the Hokkaido region.
"On January 11, there was a M4.7 earthquake at a depth of approximately 50km off-shore of Iwate prefecture. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This event occurred at the boundary between the Pacific and the continental plates.":
In this area, the same size earthquakes have repeatedly occurred at intervals of approximately 5 and a half years. No greater events have occurred in the neighboring area. It is thought that there is a small locked patch (asperity) in the area and the same size events occur periodically.
- On January 27, there were M4.1 and M4.2 earthquakes at a depth of approximately 15km in western Shizuoka prefecture. The focal mechanisms showed strike-slip faults with compression axes in an E-W direction. These events occurred within the crust. Seismic activity in this vicinity has been continuing with some decreases and increases since last mid-November.
"There have been no anomalous changes observed in the GPS data for the Tokai region.":
(This evaluation is in agreement with the views presented at the procedural meeting on January 28 of the Assessment Committee for Areas under Intensified Measures against Earthquake Disaster. (see reference below).)
(reference)
"Recent seismic and crustal activity in the Tokai region and its vicinity" (Japan Meteorological Agency, Department of Seismology and Volcanology, January 28, 2008)
"So far, there have been no changes of activity which are likely to be associated with the so-called Tokai earthquake.
There was no remarkable seismic activity in general. Under central Shizuoka prefecture, the seismicity remains at a level lower than normal within the plate, and higher within the crust. In other regions, seismic activity is generally at a normal level.
There were no notable changes observed in crustal movements in the Tokai region and its neighboring areas.
In addition, the series of seismic activity that occurred in western Shizuoka prefecture yesterday (January 27) was located within the crust, and it is not thought to be related to the Tokai Earthquake."
There is no supplementary information for the Kinki-Chugoku-Shikoku region.
There is no supplementary information for the Kyushu-Okinawa region.
Reference 1
Earthquakes that are described in the "Evaluation of Seismic Activity" (Monthly Report of Seismic Activity in Japan) have the following features.
Reference 2
Information that is described in the "Supplementary Information to the Evaluation" includes: