Capturing geographically-varying uncertainty in earthquake ground motion models or what we think we know may change

Research output: ResearchChapter

Our knowledge of earthquake ground motions of engineering significance varies geographically. The prediction of earthquake shaking in parts of the globe with high seismicity and a long history of observations from dense strong-motion networks, such as coastal California, much of Japan and central Italy, should be associated with lower uncertainty than ground-motion models for use in much of the rest of the world, where moderate and large earthquakes occur infrequently and monitoring networks are sparse or only recently installed. This variation in uncertainty, however, is not often captured in the models currently used for seismic hazard assessments, particularly for national or continental-scale studies.

In this theme lecture, firstly I review recent proposals for developing ground-motion logic trees and then I develop and test a new approach for application in Europe. The proposed procedure is based on the backbone approach with scale factors that are derived to account for potential differences between regions. Weights are proposed for each of the logic-tree branches to model large epistemic uncertainty in the absence of local data. When local data are available these weights are updated so that the epistemic uncertainty captured by the logic tree reduces. I argue that this approach is more defensible than a logic tree populated by previously published ground-motion models. It should lead to more stable and robust seismic hazard assessments that capture our doubt over future earthquake shaking.
Original languageEnglish
Title of host publicationRecent Advances in Earthquake Engineering in Europe
Subtitle of host publication16th European Conference on Earthquake Engineering-Thessaloniki 2018
EditorsKyriazis Pitilakis
Place of PublicationCham
Number of pages29
StatePublished - 25 Apr 2018

Publication series

NameGeotechnical, Geological and Earthquake Engineering
PublisherSpringer, Cham

    Research areas

  • 16ECEE, theme lecture, seismic hazard, earthquake, engineering seismology, GMPE, ground motion prediction equations, ground-motion model, uncertainty, epistemic

Bibliographical note

This is the article accompanying a theme lecture at the 16th European Conference on Earthquake Engineering in June 2018
  1. 16th European Conference on Earthquake Engineering

    Activity: Participating in or organising an eventKey-note speaker and plenary lectures at conferences

  2. 16th European Conference on Earthquake Engineering

    Activity: Participating in or organising an eventParticipation in conference

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