Development of an Empirical Ground Motion Model for Spectral Displacement Using High Rate GNSS
Description:
Large earthquakes generate intense shaking and pose a significant hazard to human life and infrastructure. They are saturated in low frequency energy, of particular concern to large structures with long period natural resonance (such as long span bridges, high rises, and base isolation systems). Displacement-based ground-motion models (GMMs), typically derived from seismic data, are meant to help quantify this hazard, but are not well constrained because of the inherent difficulties of accurately recovering displacement from inertial strong motion instruments. High-rate GNSS (HR-GNSS) is a solution to this issue, able to avoid the pitfalls of strong motion instruments and accurately record the dynamic displacements. Despite this development, new empirical models using high-rate geodetic data have not been widely developed and implemented within the earthquake engineering community.
We present our progress towards a novel empirical ground motion model for the median effective amplitude of spectral displacement (the root mean square of the orthogonal horizontal components of the Fourier amplitude spectra) using HR-GNSS at the input data. The GMM uses a dataset of 1 Hz HR-GNSS observations of 71 large (M6+) global earthquakes (2003-2021). Displacement spectra are calculated using a multitaper code, and we then use a linear mixed effects regression approach to fitting the model. The initial best fit model is presented. We also discuss ways in which the robustness of the final model could be improved via reduction of variability associated with event, site and path in the specific context of low frequency displacements.
Session: Advancing Seismic Hazard and Risk Assessment through Multi-Disciplinary Approaches [Poster]
Type: Poster
Date: 4/15/2026
Presentation Time: 08:00 AM (local time)
Presenting Author: Braden Hensley
Student Presenter: Yes
Invited Presentation:
Poster Number: 43
Authors
Braden Hensley Presenting Author Corresponding Author bhensley@uoregon.edu University of Oregon |
Valerie Sahakian vjs@uoregon.edu University of Oregon |
Jensen DeGrande jdegran@uw.edu University of Washington |
Brendan Crowell crowell.97@osu.edu Ohio State University |
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Development of an Empirical Ground Motion Model for Spectral Displacement Using High Rate GNSS
Category
Advancing Seismic Hazard and Risk Assessment through Multi-Disciplinary Approaches