September 13, 2006 Headquarters for Earthquake Research Promotion Earthquake Research Committee

	- Off-shore of Miyagi prefecture	M7.2 on August 16, 2005 (depth approximately 40km)
	- Chuetsu region, Niigata prefecture	M5.0 on August 21, 2005 (depth approximately 15km)
	- Off-shore of Ibaraki prefecture	M6.3 on October 19, 2005 (depth approximately 50km)
	- Off-shore of Sanriku	M7.2 on November 15, 2005
	- Hyuganada	M5.5 on March 27, 2006 (depth approximately 35km)
	- Off-shore east of the Izu Peninsula	seismic activity with M5.8 on April 21 and M4.5 on April 30, 2006
	- Central Oita	M6.2 on June 12, 2006 (depth approximately 150km)

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2 Nationwide Seismic Activity by Region

(1) Hokkaido Region

There is no supplementary information for the Hokkaido region.

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(2) Tohoku Region

"On August 17, there was a M4.3 earthquake at a depth of approximately 75km off-shore of Miyagi prefecture.":
This event occurred within the aftershock region of the earthquake off-shore of Miyagi prefecture on May 26, 2003 (M7.1, maximum seismic intensity 6 Lower).

- Although it has been a year since the earthquake off-shore of Miyagi prefecture that occurred on August 16, 2005 (M7.2, maximum seismic intensity 6 Lower), the postseismic movements that were observed following the earthquake at the GPS observation stations around the Oshika Peninsula, have been continuing at a low level.

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(3) Kanto-Chubu Region

"On August 31, there was a M4.8 earthquake at a depth of approximately 75km under Tokyo Bay. The focal mechanism showed a reverse fault with a compression axis in an E-W direction. This event occurred near the boundary between the Pacific and the Philippine Sea plates.":
In this vicinity, there was a M6.0 earthquake (maximum seismic intensity 5 Upper) on July 23, 2005.

"There have been no remarkable changes observed in GPS data in the Tokai region.":
(According to the reviews presented at the (drill) meeting of the Assessment Committee for Areas under Intensified Measures against Earthquake Disaster, at the Japan Meteorological Agency on August 31, there have been no notable changes in seismic activity or crustal movements in the Tokai region since the procedural meeting on July 31 of the Assessment Committee for Areas under Intensified Measures against Earthquake Disaster. This evaluation is in agreement with those views.)

(reference) "Recent seismic and crustal activity in the Tokai region and its vicinity" (Japan Meteorological Agency, Department of Seismology and Volcanology, July 31, 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.
The long-term crustal movements from the slow slip at the plate boundary in the Tokai region and its neighboring area, are thought to have already stopped."

- During the period from August 27 through September 1, there were low-frequency earthquakes (tremor) observed with strain and tilt changes in the area from southern Nagano prefecture through eastern Aichi prefecture. Recently similar movements were observed in eastern Aichi prefecture in July 2005, and in the area from the border of Mie and Nara prefectures through eastern Aichi prefecture in January 2006.

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(4) Kinki-Chugoku-Shikoku Region

There is no supplementary information for the Kinki - Chugoku - Shikoku region.

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(5) Kyushu-Okinawa Region

- On August 28, there was a M5.3 earthquake at a depth of approximately 120km under the ocean near Yonaguni Island.

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Supplement

- On September 9, there was a M4.9 earthquake at a depth of approximately 65km off-shore of Miyagi prefecture.

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.