- Ground-motion model is:
where E indicates expectation, v is in gal, a = 472, b = 0.278, c = 1.301.
- Excludes records for which significant soil amplification established but makes no distinction between rock
and soil sites.
- Focal depths between 9 and 70km with most about 10km. Most records from earthquakes with magnitudes
about 6.5 and most distances less than 50km. Uses records from 21 different sites.
- Notes that physical laws governing ground motion near the source are different than those governing motion
at greater distances therefore excludes records with epicentral distance or distance to fault rupture smaller
than one-half of estimated length of rupture.
- Examines correlation among the records but find negligible effect.