- Ground-motion model is: where Am is g, a1 = -1.49, a2 = 0.31, a3 = 0.0248, h = 9.4km and σ = 0.32 (for horizontal components)
and a1 = -1.92, a2 = 0.29, a3 = 0.0146, h = 6.7km and σ = 0.36 (for vertical components).
- Data from experimental strong-motion array consisting of 12 Kinemetrics PDR-1 instruments deployed in
the epicentral area of the Ms = 7.8 Tangshan earthquake of 28th July 1976. Provide details of site geology
at each station; most stations are on soil.
- Records from earthquakes recorded by only one station were excluded from analysis.
- Note that equations are preliminary and more refined equations await further studies of magnitudes and
distances used in analysis.
- Note that high anelastic attenuation coefficient may be due to biases introduced by the distribution in
magnitude-distance space and also because of errors in magnitude and distances used.