Analysis of Source Process by Far-Field Body Waves

Analysis of Source process by far-field body waves (Note 1) was performed, utilizing broad-band seismometer records collected from Data Management Center (DMC) of the Incorporated Research Institutions for Seismology (IRIS), to the earthquake in the Noto region, Ishikawa Prefecture on January 1, 2024 at 16:10 (JST) "the 2024 Noto Peninsula Earthquake" (Mj 7.6).
The rupture initiation point was assumed to be the hypocenter (37° 29.8′ N, 137° 16.2′ E, depth 16 km) determined by JMA. The fault plane was assumed to be one of the two nodal planes of CMT solution by JMA, i.e. the nodal plane dipping southeast with strike in an NE-SW direction (strike 47°, dip 37°, slip angle 100°). Maximum rupture velocity was set to be 2.4 km/s. For the calculation of theoretical waveforms, velocity structure models of CRUST2.0 (Bassin et al., 2000) and IASP91 (Kennett and Engdahl, 1991) were used. Main results are as following (provisional and may be updated).
* Main rupture area is about 120 km in the strike direction and about 30 km in the dip direction.
* Main slip expanded from the rupture initiation point about 45 km range to the northeast, and about 45 km to the southwest. Maximum slip amount was 1.7 m (rigidity of the surrounding structure was set to be 30 GPa)
* Main rupture duration time is about 40 sec.
* Moment magnitude (Mw) is 7.4.
For the detail of the results refer to https://www.data.jma.go.jp/eqev/data/world/about_srcproc.html

Japan Meteorological Agency
[Evaluation of the 2024 Noto Peninsula Earthquakes (February 9, 2024)]