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A preliminary source model composed of asperities for the 2003 Tokachi-oki, Japan, earthquake (M J M A = 8.0) was estimated by the empirical Green's function method. The source parameters for three asperities located on the fault plane were determined from the comparisons of the synthesized broad-band ground motions with the observed ones. We found that the pulsive waveforms observed in north direction of the hypocenter were generated by the forward rupture directivity effect. Furthermore, the estimates of the stress parameter for asperities are higher than the averaged ones for past inland and subduction earthquakes.

Compression tests were performed on heat-treated silicon crystals. Yield stresses of crystals depended strongly on the size and density of precipitates induced by heat treatments. Transmission electron microscope observation revealed that SiO2 precipitates larger than a few thousand angstroms became the nucleation sites of glide dislocations, causing a decrease in the yield stress, and that microprecipitates of less than several hundred angstroms acted as obstacles to dislocation movement.

Four point bending tests were performed on heat-treated CZ–Si wafers at various temperatures. The fracture stress at room temperature does not change with heat treatments if the wafer has surface-denuded zones. However, the yield stresses of wafers at 700°C are remarkebly lowered by such treatments. The heat-treated CZ wafers are deformed plastically at relatively low temperatures and deformation twins appear in such low temperature plastic deformation. Their appearance is closely related to deformation temperature, strain rate and the presence of the thermally induced defects.