|
November 12, 2007 |
| * | On October 1, there was a M4.9 earthquake in western Kanagawa prefecture. This event had a maximum seismic intensity 5 Upper. Associated with this event, there was some light damage. to supplementary reports |
| * | On October 9, there was a M5.8 earthquake at a depth of approximately 40km off-shore east of Hokkaido. The focal mechanism showed a reverse fault with a compression axis in a NW-SE direction. This event is related to the subducting Pacific plate. to supplementary reports |
| * | There was no remarkable activity. to supplementary reports |
| * | On October 1, there was a M4.9 earthquake at a depth of approximately 15km in western Kanagawa prefecture. The focal mechanism had a compression axis in a NNW-SSE direction. This event is related to the subducting Philippine Sea plate. Aftershock activity was strong for a few hours after the main shock. However it subsided within two days. |
| * | On October 22, there was a M4.3 earthquake at a depth of approximately 10km under the ocean area near Niijima and Kozushima. |
| * | On October 17, there was a M3.7 earthquake at a depth of approximately 15km in the Chuetsu region, Niigata prefecture. This event occurred within the aftershock area of the 2004 Niigata Chuetsu Earthquake. |
| * | There have been no anomalous changes observed in the GPS data for the Tokai region. to supplementary reports |
| * | On October 14, there was a M3.7 earthquake at a depth of approximately 10km in eastern Shimane prefecture. This event occurred at the location slightly NW of the aftershock area of the 2000 Western Tottori Earthquake. to supplementary reports |
| * | On October 17, there was a M5.4 earthquake at a depth of approximately 40km under the ocean area near the Okinawa Main Island. The focal mechanism showed a strike-slip fault with a tension axis in a NW-SE direction. It is thought that this event occurred within the Philippine Sea plate. to supplementary reports |
| * | On October 25, there was a M6.2 earthquake off-shore east of the Chishima Islands. This event occurred within the aftershock area of the M8.2 earthquake on January 13, 2007. |
November 12, 2007
The following are the numbers of earthquakes by magnitude that occurred in Japan and the surrounding area during October 2007.
(reference)
The following regions have been noted as having significant seismic activity during the period from October 2006 to the end of September 2007.
| - Off-shore east of the Chishima Islands | M7.9 on November 15, 2006 | |
| - Off-shore east of the Chishima Islands | M8.2 on January 13, 2007 | |
| - Noto Hanto Earthquake in 2007 | 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 |
There is no supplementary information for the Hokkaido region.
Seismic activity of earthquakes equal to or larger than M5.0 on the Pacific side of the Tohoku region has been declining to a level lower than usual since the beginning of this year.
"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 October 29 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, October 29, 2007)
" 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, 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, some crustal movements and low-frequency earthquakes apparently associated with the "short-term slow slip"
at the plate boundary, were observed in Aichi prefecture during the periods from September 26 to October 2 and from October 6 to 12.
In this vicinity, similar phenomena were seen in June this year."
There is no supplementary information for the Kinki-Chugoku-Shikoku region.
- Since October 30, there was light seismic activity at a shallow location
in central Oita prefecture and the largest earthquake was an M3.0 event.
In June this year, there was seismic activity with a maximum event of M4.9
at nearly the same location.
- On November 6, there was a M4.1 earthquake at a depth of approximately 10km near the border between Osaka and Nara prefectures [in Nara prefecture].
[ ] was the regional name of the epicenter used in the Japan Meteorological Agency announcement.
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: