13 December 2000 |
Headquarters for Earthquake Research Promotion |
Earthquake Research Committee |
Seismic activity in November 2000
On November 14th, there was an M4.4 earthquake at a depth of about 10 km near Iriomotejima, which registered a maximum seismic intensity of 5 lower. to supplementary reports
On November 14th, there was an M5.9 earthquake at a depth of 50 km in the sea off Kushiro. An M5.2 event occurred on the same day in about the same location. The focal mechanism for both events was a reverse fault type with a northwest-southeast pressure axis. These earthquakes occurred in conjunction with the subduction of the Pacific Plate. to supplementary reports
On November 16th, there was an M5.0 event at a depth of about 50 km in the sea off Fukushima Prefecture. This earthquake occurred in conjunction with the subduction of the Pacific Plate. to supplementary reports
*Although there has been a recent trend toward the resumption of seismic activity within the subducting Philippine Sea Plate in central Shizuoka Prefecture, the overall activity level has continued to be lower than average since August of last year. However, results of GPS observation and leveling surveys of Tokai region show no marked changes in the trends seen to present. to supplementary reports
Since the beginning of November, the aftershock activity following the M7.3 (tentative data) 2000 Western Tottori Earthquake that occurred on October 6 has gradually declined; there was, however, an M4.5 aftershock in the northern part of the aftershock zone on the third. Furthermore, the triggered by the M7.3 (tentative) event in the areas 25 km WSW and 30 km ENE of the aftershock zone has also gradually been declining. to supplementary reports
*On November 14th, there was an M4.4 event at a depth of about 10 km near Iriomotejima, which registered a maximum seismic intensity of 5 lower. The middle of the month was briefly active, with three M4.0 or greater events including this one. to supplementary reports
*On December 5th, there was an M5.3 event at a depth of about 40 km in the sea off Ibaraki Prefecture.
*On December 7th, there was an M4.2 aftershock to the 2000 Western Tottori Earthquake at a depth of about 10 km in eastern Shimane Prefecture.
December 13, 2000 |
Earthquake Research Committee |
-Kumamoto region of Kumamoto Prefecture (at a depth of about 10 km), off the coast of Fukui Prefecture (at a depth of about 15km) | |
and western Aichi Prefecture (at a depth of about 50 km), in November 1999, all M4.0 or greater earthquakes | |
-Off the eastern coast of Hokkaido | 28 January, 2000, an M6.8 event (at a depth of about 60 km) |
-Iburi administrative district (in the vicinity of Mt. Usuzan) | |
30 March, 2000, an M4.3 event (at a depth of less than 10 km) and 1 April, an M4.6 event (at a depth of less than 10 km), seismic activity associated with the volcanic activity | |
-Northeastern Chiba Prefecture | 3 June 2000, M6.0 (at a depth of about 50km) |
-Off the west coast of Ishikawa Prefecture | 7 June 2000, M6.1 (at a depth of less than20 km) |
-The Kumamoto region of Kumamoto Prefecture | 8 June 2000, M4.8 (at a depth of about 10km) |
-In the area from Miyakejima to Niijima-Kozushima | There was seismic activity associated with magma activity, including events of M6.4 (at a depth of 10 km) on July 1st, and M6.4 (at a depth of 10 km) on July 30th. |
-The sea off Ibaraki Prefecture | July 21st 2000, M6.0 (at a depth of 50 km) |
-from the area near Miyakejima to the area near Niijima-Kozushima | |
In August 2000, there were five M5.0 or greater events (on August 18th, maximum M6.0). | |
-from the area near Miyakejima to the area near Niijima-Kozushima | |
September 11th 2000, in the sea west of Toshima, an M5.3 event | |
-Western Tottori Prefecture | On October 6th, there was an M7.3 (tentative) event (at a depth of about 10 km) |
There are no supplements in the Tohoku Region.
Corrections:
In the Seismic activity in September 2000 report issued by this committee on October 11th, there was an error in the "Major seismic activity" supplementary section.
Error: (4 to 6 lines from the top of the section) "... as of the end of August this year."
Correct: (4 to 6 lines from the top of the section) "... as of the end of September this year."
Reference Material 1 Standards to select earthquakes which are to be described in "Evaluation of Seismic Activity" (Monthly Report of Seismic Activity in Japan) Events of M6.0 or greater. Or, M4.0 or greater (M5.0 or greater at sea) and having a maximum intensity of 3 or greater. Reference Material 2 Standards to describe additional explanation in "Supplementary repot of the evaluation." 1 Reference items relating to seismic activity described in "Evaluation of Seismic Activity". 2 Activity related to seismic activity (of the past 12 months or so) described in "Major Seismic Activity in Evaluation of Seismic Activity." 3 Activity that have been evaluated but not described in "Evaluation of Seismic Activity" because of being within the bounds of normal activity or because the activity is not prominent. |