The following are the numbers of earthquakes by magnitude that occurred in Japan and the surrounding area during September 2006.
The following regions have been noted as having significant seismic activity
during the period from September 2005 to the end of August 2006.
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- Off-shore of Ibaraki prefecture
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M6.3 on October 19, 2005(depth approximately 50km) |
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- Off-shore of Sanriku |
M7.2 on November 15, 2005
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- Hyuganada |
M5.5 on March 27, 2006(depth approximately 35km)
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- Off-shore east of the Izu Peninsula |
seismic activity with M5.8 on April 21 and M4.5 on April 30, 2006
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- Central Oita |
M6.2 on June 12, 2006(depth approximately 150km)
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to the text
2 Nationwide Seismic Activity by Region
(1) Hokkaido Region
There is no supplementary information for the Hokkaido region.
to the text
(2) Tohoku Region
-On September 9, there was a M4.9 earthquake at a depth of approximately
65km off-shore of Miyagi prefecture.:
to the text
(3) Kanto-Chubu Region
"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 September 25 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, September 25, 2006)
"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. The seismicity remains at a level lower than normal directly under the area from eastern Hamana Lake through central Shizuoka prefecture. 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, from late August until early September, some crustal movements and low-frequency earthquakes apparently associated from the short-term slow slip at the plate boundary, were observed in the region from eastern Aichi through southern Nagano prefectures. In this vicinity, similar phenomena were seen 22 times over the past six years. The last time was in January of this year."
to the text
(4) Kinki-Chugoku-Shikoku Region
There is no supplementary information for the Kinki - Chugoku - Shikoku
region.
to the text
(5) Kyushu-Okinawa Region
- On September 23, there was a M4.4 earthquake under the ocean near Miyakojima.
to the text
(6) Other Regions
- On September 16, there was a M5.8 earthquake at a depth of approximately 410km under the central region of the Japan Sea.
- On September 28, there was a M6.0 earthquake off-shore east of the Chishima Islands. Also, at nearly the same location, there were M6.8 and M6.6 earthquakes on October 1.
to the text
Supplement
On October 9, there was a M6.1 earthquake off-shore south of Taiwan.
Reference 1
Earthquakes that are described in the "Evaluation of Seismic Activity"(Monthly Report of Seismic Activity in Japan) are events of M6.0 and greater, or events of M4.0 and greater (M5.0 or greater off-shore) that have maximum intensity of 3 or greater.
Reference 2
Information that is described in the "Supplementary Information to the
Evaluation" includes:
| 1) |
Reference information
related
to seismic activity described in the "Evaluation of Seismic Activity" |
| 2) |
Recent earthquake
activity
over the past year related to the events described in "Major Seismic
Activity" in the "Evaluation of Seismic Activity" |
| 3) |
Seismic activity that has
been evaluated, but not included in the "Evaluation of Seismic Activity" because it is within normal bounds and not prominent. |
|