Site parameters applied in NGA-Sub database
Journal
Earthquake Spectra
Journal Volume
38
Journal Issue
1
Pages
494-520
Date Issued
2022
Author(s)
Abstract
NGA-Sub data resources are organized into a relational database. We describe the Site table within that database structure, which contains metadata for 6502 stations that have recorded earthquakes incorporated into the database. Critical site parameters for ground motion modelling are time-averaged shear-wave velocity (VS) in the upper 30 m of the site (VS30) and depths to various VS horizons (1.0 and 2.5 km/s). We compile VS profiles for the global study regions and use these data to compute VS30 where profile data is available from reliable sources. When this is not the case, which is commonly encountered in many regions, we adopt a proxy-based VS30-estimation framework whereby estimates are provided, in order of preference, from locally derived models, models derived for a source region and applied to a different target region with some degree of validation, and global or source-region models applied to a target region without validation. Epistemic uncertainties in category median VS30 are provided when proxy-based models are required but their validation is not possible. Sediment depth terms are also evaluated using measured VS profiles that exceed measured velocity thresholds where available or are estimated for regions having 3D seismic velocity models (e.g. Cascadia, Japan, New Zealand, and Taiwan). © The Author(s) 2021.
Subjects
relational database; sedimentary basins; shear wave velocity; site parameters; Site response
SDGs
Other Subjects
Acoustic wave velocity; Earthquakes; Shear flow; Uncertainty analysis; Wave propagation; Data resources; Database structures; Ground motion modeling; Relational Database; Sedimentary basin; Shear wave velocity; Site parameter; Site response; Source region; Target regions; Shear waves; database; ground motion; metadata; S-wave; sedimentary basin; seismic velocity; three-dimensional modeling; wave velocity
Type
journal article