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Development of Ground Motion Models in Central and Eastern United States for Use in the Coastal Plain Using Sediment Thickness

Description: 

This study focuses on developing ground-motion models, specifically Pezeshk et al. (2018), initially derived for areas outside the Coastal Plain, to enhance their applicability within Coastal Plain regions. The adjustment factors developed are intricately linked to sedimental thickness and rupture distance within the Coastal Plain. Utilizing recently established sediment thickness contour maps by Boyd et al. (2023), our approach incorporates an integrated dataset that combines the NGA-East original dataset (Goulet et al., 2014), data from Chapman and Guo (2021) and a newly compiled and verified dataset by Thompson et al. (2023). Residuals are computed by contrasting the logarithms of observed data against those predicted by Pezeshk et al. (2018) ground-motion models while considering the site amplification model of Stewart et al. (2020) and employing three datasets. Through a mixed-effects regression, we conduct residual analyses to partition total residuals into components attributed to between-events and within-event residuals. We tailor an equation correlating within-event residuals and sediment depth and rupture distance. The outcomes reveal that, for stations within the Coastal Plain region, the proposed correction significantly eliminates residual trends (with respect to VS30, sediment depth, and rupture distance) across most periods. These findings have practical implications for seismic hazard and risk analyses at sites within the Coastal Plain, emphasizing the importance of incorporating sediment thickness considerations for more accurate predictions

Session: The 2023 USGS National Seismic Hazard Model and Beyond - III

Type: Oral

Date: 5/1/2024

Presentation Time: 02:30 PM (local time)

Presenting Author: Mohsen

Student Presenter: Yes

Invited Presentation: 

Authors