- Ground-motion model is:
where Sa is in g, b1 = -1.038, b2 = 0.387, b3 = -1.159, b4 = 2.600, b5 = 0.123 and σ = 0.287.
- Use two site classes:
- Eurocode 8 site class A, V s30 > 800m∕s. 64 records. S = 0.
- Eurocode 8 site class B (21 records) or C (8 records), 180 < V s30 < 800m∕s. S = 1.
- Most records from Mw < 6.6.
- Assume magnitude-independent decay rate, linear magnitude dependency and no anelastic term because
insufficient data to do otherwise.
- Data primarily from south Iceland supplemented with records from Greece, Turkey and Slovenia.
- Exclude distant records because of low engineering significance and to minimise differences in anelastic
decay between regions.
- Records from strike-slip earthquakes except for data from one oblique-faulting Icelandic earthquake. Select
earthquakes from extensional regimes.
- Do not exclude data from buildings because of limited records. Exclude data from Thjorsarbru Bridge
because they show clear structural effects and site dependent conditions not characteristic of study area
as a whole.
- Records processed using individually-chosen filters.
- Show comparisons between predicted and observed normalized ground motions w.r.t. distance and conclude
that selected functional form fits the data sufficiently well.
- Note that correlation matrix shows strong multi-collinearity between coefficients, which implies imprecise
estimates of regression coefficients meaning that outside the range of the data predictions could be