The document discusses research analyzing the relationship between geodetic strain, seismicity, and faulting in Japan. It presents results on fractal analyses of faulting and seismicity, correlations between seismic b-value and strain, temporal and spatial variations in seismicity, and relationships between GPS-derived deformation, strain, fault type and seismic hazard parameters. The overall aim is to evaluate how geodetic strain correlates with earthquake distribution, rate and magnitude over different time periods to improve understanding of seismic hazards.

1. The relationship of geodetic strain to seismicity on the island arc of Japan Ali O. Oncel Geological Survey of Japan

3. FRACTAL ANALYSIS OF FAULTING (Oncel, Wilson and Nishizawa, JGR-2001) Correlation coefficients between b and D S computed along lines 1-3 are contoured to illustrate the spatial distribution of positive and negative correlation regions (areas 1-3) throughout Japan If pattern has fractal properties then N = Cr -D N :the number of occupied boxes r: the length of the box (r).

6. Correlations of seismotectonic variables (Oncel, Wilson and Nishizawa, JGR-2001) Active faults in Japan digitized from the 1:200,000 active fault maps produced by the Research Group for Active Faults of Japan (1991).

7. Mapping the correlations of seismotectonic variables (Oncel, Wilson and Nishizawa, JGR-2001) Correlation coefficients between b and D S computed along lines 1-3 are contoured to illustrate the spatial distribution of positive and negative correlation regions (areas 1-3) throughout Japan Tohoku Events: Recent seismic events in the Tohoku region (M=5.5 and 6.2) were located in a positive correlation (Area III) noted to be anomalously quiescent. These intermediate magnitude events caused considerable damage and were characterized by higher than normal intensity for earthquakes of this magnitude. Negative Correlations :Observed in the areas accommodates rupture on interconnected faults of larger total surface and therefore larger seismic moment. Positive Correlations: Observed in the areas where stress is released by lower magnitude seismicity on smaller fault strands. 5.00 to 6.00 6.00 to 7.00 1998-2003 M=6.2 2003.07.26 M=5.5 2003.07.26

8. Temporal variations of Seismicity (Oncel et al.,PAGEOPH-1996, Oncel and Wilson, BSSA-2001)

9. Temporal variations of Seismicity (Oncel et al.,Nonlinear Geophys-1995, Oncel and Wilson.BSSA-2001)

10. Spatial variations of Seismicity (Oncel et al., Tectonophysics-1996, Oncel and Wilson, BSSA-2001)

11. GPS and Earthquake Mechanism Reilinger, Toksoz and Barka, GSA-2000 We know that changes in the recent deformation observed by GPS measurement reveals dependence on fault type and velocity field. Velocity is lower for lateral motion while it is observed to be higher for vertical motion. Relationships between GPS derived deformation rate and Seismic Hazard has not, as yet, been proposed.

12. GPS and Hazard Parameters Modified after (Oncel and Wyss, 2000) Changes in GPS measurement seems to be partially related to the fault patches of seismic (asperity) and aseismic (creep). Especially, GPS velocity vectors is smaller in northern strand of NAFZ indicating higher seismic hazard while observing larger in its southern strand.

13. Contour Map of the 10 year Area Strain Data (Wilson, Kano, and Nishizawa, in revision, PAGEOPH)

14. Contour Map of the 100 year Area Strain Data (Wilson, Kano, and Nishizawa, in revision, PAGEOPH)

15. Correlations of seismotectonic variables Station locations from which horizontal crustal strain measurements were made. Active faults in Japan digitized from the 1:200,000 active fault maps produced by the Research Group for Active Faults of Japan (1991).