Seismic scaling relation of the 2007 Off Mid Niigata, Japan, earthquake (Mw 6.6) sequence in comparison with two other earthquake (Mw 6.6) sequences
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2008
Received: 15 November 2007
Accepted: 30 January 2008
Published: 18 November 2008
The relationship of seismic moment (M0) to corner frequency (fc) of the 2007 Off Mid Niigata prefecture (Chuetsu-oki) earthquake sequence is examined in comparison with that of two other earthquake sequences. The M0-f0 relation of this sequence (3.4 ≤ Mw ≤ 6.6) is M0 ∝ f c −3.87 , which deviates from M0 ∝ f c −3 . The relatively large deviation from f c −3 may reflect the influence of fluids identified in tomographic studies around the source region of the tectonic strain concentration. Moreover, the lower fcs of the small events (3.4 ≤ Mw ≤ 3.8) in this sequence are similar to those of off-main-fault events in the 2004 Mid Niigata prefecture earthquake sequence. The characteristics in the scaling relation may be interpreted in the context of the event locations, which are either on- or off-main faults, and may have implications for the seismogenic conditions. Key words: The 2007 Off Mid Niigata earthquake, seismic scaling, seismogenic conditions.