- Ground-motion model is:
where Y is in nm∕s2, b = 0.868, d = -0.001059, σ = 0.35, for horizontal PGA a = 5.230 and for vertical
PGA a = 5.054.
- Most records from rock sites.
- Focal depths between 0 and about 27km (most less than 10km).
- Most records from ML < 3.5.
- Most earthquakes have strike-slip mechanism.
- Uses records from high gain short period seismographs and from strong-motion instruments.
- Records are instrument corrected.
- Eliminates some far-field data from small magnitude earthquakes using signal to noise ratio criterion.
- Records cover entire azimuthal range.
- Notes that need more data in near field.
- Notes that care must be taken when using equations for prediction of ground motion in strong earthquakes
(M ≈ 6) because of lack of data.