2.279 Graizer and Kalkan (2007, 2008)

• Ground-motion model is:
where Y is in g, c1 = 0.14, c2 = -6.25, c3 = 0.37, c4 = 2.237, c5 = -7.542, c6 = -0.125, c7 = 1.19, c8 = -6.15, c9 = 0.525, bv = -0.25, V A = 484.5, R1 = 100km and σ = 0.552.
• Characterise sites by V s,30 (average shear-wave velocity in upper 30m). Note that approximately half the stations have measured shear-wave velocity profiles.
• Include basin effects through modification of D1. For sediment depth (Z 1km D1 = 0.35; otherwise D1 = 0.65.
• Use three faulting mechanism classes:
Normal
13 records
Strike-slip
1120 records. F = 1.00.
Reverse
1450 records. F = 1.28 (taken from previous studies).

but only retain two (strike-slip and reverse) by combining normal and strike-slip categories.

• Only use earthquakes with focal depths < 20km. Focal depths between 4.6 and 19km.
• Exclude data from aftershocks.
• Use data from: Alaska (24 records), Armenia (1 record), California (2034 records), Georgia (8), Iran (7 records) Italy (10 records), Nevada (8 records), Taiwan (427 records), Turkey (63 records) and Uzbekistan (1 record).
• Most data from 5.5 Mw 7.5.
• Adopt functional form to model: a constant level of ground motion close to fault, a slope of about R-1 for > 10km and R-1.5 at greater distances (> 100km) and observation (and theoretical results) that highest amplitude ground motions do not always occur nearest the fault but at distances of 310km.
• Choose functional form based on transfer function of a SDOF oscillator since this has similar characteristics to those desired.
• Note that magnitude scaling may need adjusting for small magnitudes.
• Firstly regress for magnitude and distance dependency and then regress for site and basin effects.
• Examine residual w.r.t. magnitude and distance and observe no significant trends.
• Compare predictions to observations for 12 well-recorded events in the dataset and find that the observations are well predicted for near and far distances.
• Demonstrate (for the 2004 Parkfield earthquake) that it is possible to add an additional ‘filter’ term in order to predict ground motions at large distances without modifying the other terms.