%0 Journal Article
%@ 1570-761X
%A Douglas, John
%A Suhadolc, Peter
%A Costa, G.
%A Department of Civil & Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK,
%A Universitá degli studi di Trieste, Dipartimento di Scienze della Terra, Via E. Weiss 1, 34127 Trieste, Italy,
%D 2004
%F epos:1444
%I Springer Verlag
%J Bulletin of Earthquake Engineering
%K attenuation relations, crustal structure, modal summation, strong ground motion estimation
%N 1
%P 75-99
%T On the Incorporation of the Effect of Crustal Structure into Empirical Strong Ground Motion Estimation
%U https://episodesplatform.eu/eprints/1444/
%V 2
%X This article has two purposes. Firstly, a validation exercise of the modal summation technique for the computation of synthetic strong-motion records is performed for two regions of Europe (Umbria-Marche and south Iceland), using a variety of region specific crustal structure models, by comparing the predicted ground motion amplitudes with observed motions. It is found that the rate of decay of ground motions is well predicted by the theoretical decay curves but that the absolute size of the ground motions is underpredicted by the synthetic time-histories. This is thought to be due to the presence of low-velocity surface layers that amplify the ground motions but are not included in the crustal structure models used to compute the synthetic time-histories. Secondly, a new distance metric based on the computed theoretical decay curves is introduced which should have the ability to model the complex decay of strong ground motions. The ability of this new distance metric to reduce the associated scatter in empirically derived equations for the estimation of strong ground motions is tested. It is found that it does not lead to a reduction in the scatter but this is thought to be due to the use of crustal structure models that are not accurate or detailed enough for the regions studied.