Abstract
A large shallow earthquake occurred in the Noto Peninsula on March 25, 2007. The Japan Meteorological Agency (JMA) estimated the hypocenter and origin time to be 136.685E, 37.220N and 09:41:57.9 JST, respectively, and the depth to be 11 km. The magnitude of the main shock is Mj (JMA scale) 6.9 and Mw 6.6, and the focal mechanism of the main shock is a reverse fault with right-lateral components. The strike, dip and rake are 58◦, 66◦ and 132◦, respectively, according to the National Research Institute for Earth Science and Disaster Prevention (NIED). The two largest aftershocks of Mj 5.4 occurred at the northeast and southwest edges of the aftershock area, at 18:11 on May 25 and at 07:16 on May 26, respectively. A maximum seismic intensity, 6 upper on the JMA scale, was observed at several stations situated in the source area. The earthquake caused severe damage on the Noto Peninsula and in the surrounding prefectures of Ishikawa, Toyama, Niigata and Fukui. The final report of the Fire and Disaster Management Agency reported one human fatality, 356 people injured and 29,349 houses completely and partially collapsed. Although several moderate-sized earthquakes had occurred in the northeast and southern parts of Noto Peninsula prior to this event, there is no record of large earthquakes with M > 7 occurring in this area during the last 1500 years. In addition, events of M 6.0 ∼ 6.5 have never occurred in the source region of the March 25, 2007 earthquake, and even the seismic activity of small and microearthquakes has been very low for more than 25 years, based on the high-gain seismic-observations by the Kamitakara Observatory, Kyoto University (Ito et al., 2007). Large active faults have not been identified on land in the source area. Nevertheless, some offshore faults in west off Noto Peninsula have nearly the same strike as that of the aftershock area, which may be related to the March 25, 2007 earthquake. Well-arranged high-density nation-wide networks have been constructed, and these provided abundant data for the sequence of the earthquake. In particular, strong-motion and high-gain earthquake records as well as the GPS data provided fundamental information on the earthquake sequence and related phenomena from immediately after the main shock. In addition, temporary dense seismic stations were deployed for aftershock observations
Highlights
Several moderate-sized earthquakes had occurred in the northeast and southern parts of Noto Peninsula prior to this event, there is no record of large earthquakes with M > 7 occurring in this area during the last 1500 years
The results of some of these surveys can be found in various special sections of Earth, Planets and Space, including the 2000 Western Tottori earthquake, the M 7.1 and M 6.4 earthquakes in northwestern Japan, the 2004 Mid-Niigata earthquake and the 2005 West Off Fukuoka Prefecture earthquake
These special sections provide useful information that is valuable for improving our deep understanding of the inland earthquakes and facilitating the identification of the characteristics that these inland earthquakes have in common, as well as those that differ
Summary
Several moderate-sized earthquakes had occurred in the northeast and southern parts of Noto Peninsula prior to this event, there is no record of large earthquakes with M > 7 occurring in this area during the last 1500 years. Magnetoterullic and gravimetric observations as well as seismic surveys were carried out with the aim of obtaining a better understanding of the structures in the source area. Since the 2000 Western Tottori earthquake of Mj 7.3, detailed surveys by dense observation stations have been conducted for moderate and large earthquakes.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
