- Ground-motion model is:
where ymax is in cm∕s2, α = 0.429, c = 2.976, β = 5.396 and σ = 0.15.
More complicated functional form unwarranted due to limited distance range.
- Depths between 15 and 20km.
- Only use data from a single firm site (Ciudad Universitaria), on a surface layer of lava flow or volcanic
- Only records from coastal earthquakes.
- Residuals plotted against distance, no trends seen.
- Give amplification factor for lake bed sites (25 to 80m deposit of highly compressible, high water content
clay underlain by resistant sands), but note based on only a few sites so not likely to be representative of
entire lake bed.