July 10, 2012
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion
There was no remarkable activity
There was no remarkable activity
* On June 18, there was a M6.2 earthquake at a depth of approximately 45 km, offshore Miyagi prefecture. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This event occurred on the boundary between the Pacific and the continental plates.
* On June 1, there was a M5.1 earthquake at a depth of approximately 45 km under northwestern Chiba prefecture [southern Ibaraki prefecture]. The focal mechanism showed a reverse fault with a compression axis in an NNW-SSE direction. This event occurred on the boundary between the Philippine Sea and the continental plates.
* On June 6, there was a M6.3 earthquake offshore east of Chiba prefecture. The focal mechanism showed a strike-slip fault with a compression axis in an N-S direction.
* On June 17, there was a M4.5 earthquake at a depth of approximately 50 km under southern Ibaraki prefecture. The focal mechanism showed a reverse fault with a compression axis in an NW-SE direction. This event occurred on the boundary between the Philippine Sea and the continental plates.
* On June 29, there was a M4.5 earthquake at a very shallow depth in southern Chiba prefecture. The focal mechanism had a compression axis in an NNE-SSW direction. This event occurred within the crust.
* In the GNSS data for the Tokai region, there have been no changes of activity which are likely to be associated with the Tokai earthquake.
There was no remarkable activity.
* On June 4 at 15:51, there was a M4.4 earthquake at a depth of approximately 10 km in the foot of mountains in southern Miyazaki prefecture. The focal mechanism had a tension axis in a WNW-ESE direction. This event occurred within the crust. On the same day at 14:09, there was a M3.8 earthquake.
* On June 10, there was a M6.0 earthquake at a depth of approximately 70 km in the vicinity of Taiwan. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction.
* On July 3, there was a M5.2 earthquake at a depth of approximately 90 km under southern Chiba prefecture [Tokyo Bay]. The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This event occurred within the Pacific plate.
Note: [ ] was the regional name of the epicenter used in the Japan Meteorological Agency announcement.
GNSS (Global Navigation Satellite System) is a general name of satellite
positioning system such as GPS.
July 10, 2012
Earthquake Research Committee
The following are the numbers of earthquakes by magnitude that occurred in Japan and the surrounding area during June 2012.
(reference)
The following events for the period from June 2011 to late May 2012 have been listed as "Major Seismic Activities" in monthly "Evaluation of Seismic Activitie"
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– Chuetsu Region, Niigata Prefecture | M4.7 on June 2, 2011 (Depth of approximately 5 km) |
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– Offshore Iwate Prefecture | M6.9 on June 23, 2011 (Depth of approximately 35 km) |
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– Central Nagano Prefecture | M5.4 on June 30, 2011 (Depth of approximately 5 km) |
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– Northern Wakayama Prefecture | M5.5 on July 5, 2011 (Depth of approximately 5 km) |
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– Offshore Sanriku | M7.3 on July 10, 2011 |
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– Southern Ibaraki Prefecture | M5.4 on July 15, 2011 (Depth of approximately 65 km) |
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– Suruga Bay | M6.2 on August 1, 2011 (Depth of approximately 25 km) |
| – Offshore Fukushima Prefecture | M6.5 on August 19, 2011 (Depth of approximately 50 km) |
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– Central Hidaka Region | M5.1 on September 7, 2011 (Depth of approximately 10 km) |
| – Northern Ibaraki Prefecture | M5.2 on September 21, 2011 (Depth of approximately 10 km) |
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| – Hamadori, Fukushima Prefecture | M5.4 on September 29, 2011 (Depth of approximately 10 km) |
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| – Kumamoto Region, Kumamoto Prefecture | M4.5 on October 5, 2011 (Depth of approximately 10 km) |
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– Northern Ibaraki Prefecture | M5.3 on November 20, 2011 (Depth of approximately 10 km) |
| – Northern Hiroshima Prefecture | M5.4 on November 21, 2011 (Depth of approximately 10 km |
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| – Offshore Urakawa | M6.2 on November 24, 2011 (Depth of approximately 45 km) |
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– Offshore Fukushima Prefecture | M5.1 on January 23, 2012 (Depth of approximately 50 km) |
| – Eastern Yamanashi Prefecture-Fujigoko | M5.4 on January 28, 2012 (Depth of approximately 20 km) | |
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– Near Sado | M5.7 on February 8, 2012 (Depth of approximately 15 km) |
| – Northern Ibaraki Prefecture | M5.2 on February 19, 2012 (Depth of approximately 5 km) |
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| – Offshore Ibaraki Prefecture | M5.3 on March 1, 2012 (Depth of approximately 55 km) |
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| – Northern Ibaraki Prefecture | M5.4 on March 10, 2012 (Depth of approximately 5 km) |
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| – Offshore Sanriku | M6.9 on March 14, 2012 | |
| – Offshore East of Chiba Prefecture | M6.1 on March 14, 2012 (Depth of approximately 15 km) |
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| – Offshore Iwate Prefecture | M6.6 on March 27, 2012 (Depth of approximately 20 km) |
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| – Offshore Fukushima Prefecture | M5.9 on April 1, 2012 (Depth of approximately 55 km) |
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| – Northeastern Chiba Prefecture | M5.8 on April 29, 2012 (Depth of approximately 50 km) |
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| – Offshore East of Aomori Prefecture | M6.1 on May 24, 2012 (Depth of approximately 60 km) |
There is no supplementary information for the Hokkaido region.
– In the region from Hamadori, Fukushima prefecture through northern Ibaraki prefecture, brisk seismicity has been continuing since the 2011 off the Pacific Coast of Tohoku Earthquake.
– In the aftershock area of the 2011 off the Pacific Coast of Tohoku Earthquake, brisk seismicity has been seen. There is fear that large aftershocks will occur from now on, and there is a possibility that it will be hit by strong shaking and high tsunami. Crustal movements to the east which are thought to be the postseismic deformation have still been observed in a wide area from the Tohoku through the Kanto-Chubu regions, but they have gradually been decaying.
"In the GNSS data for the Tokai region, there have been no changes
of activity which are likely to be associated with the Tokai earthquake":
(This evaluation is in agreement with the views presented at the regular
meeting on June 25 of the Assessment Committee for Areas under Intensified
Measures against Earthquake Disaster (reference below).)
(Reference)
Recent seismic and crustal activity in the Tokai region and its vicinity (Seismological and Volcanological Department, Japan Meteorological Agency, June 25, 2012)
"No changes of activity which are likely to be associated with the Tokai earthquake have been observed until now. (Excerpted))"
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: