Authors / CoAuthors
Ebrahimi, R. | Allen, T. | Jones, A. | Ghasemi, H. | Attanayake, J.
Abstract
Spatially heterogeneous ground motions generated by earthquakes are partially attributed to near surface conditions (i.e., site response), quantification of which enables the selection and calibration of region-specific ground-motion models (GMMs) used in seismic hazard assessments. The 21 September 2021 MW 5.9 earthquake, the largest magnitude earthquake instrumentally recorded in Victoria, was well recorded across the University of Melbourne’s seismic network (UMSN) in eastern Victoria, providing a rare opportunity to assess the utility of published GMMs for large-magnitude earthquakes, and thereby improve seismic hazard assessment in the region. To benchmark these ground-motion recordings, estimating seismic site response is required, in support of which we present results of site characterisation for 12 UMSN. The analysis of surface wave components of ambient noise using microtremor surveys can provide well constrained shear-wave velocity models for the uppermost few hundred metres of the subsurface. By combining spatially averaged coherency (SPAC) and frequency-wavenumber (FK) array techniques, we retrieve multimode Rayleigh and Love phase velocity dispersion curves and Rayleigh-wave ellipticity, which we jointly invert for site-specific, near-surface shear wave velocity models. Previous studies demonstrate that incorporating dispersion of Love waves in the inversions provide stronger constraints of the uppermost shear-wave velocity structure. These inversions produced a set of representative 1-D shear wave velocity profiles for each site, which will contribute to the Australian Ground-Motion Database - a national repository of earthquake ground-motion data and site metadata for engineering applications. Presented at the 2023 Australian Earthquake Engineering Society (AEES) National Conference
Product Type
document
eCat Id
149645
Contact for the resource
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Resource provider
Point of contact
- Contact instructions
- Place and Communities
Keywords
- theme.ANZRC Fields of Research.rdf
-
- EARTH SCIENCES
-
- shear wave velocity
-
- joint inversion,
-
- ellipticity curve
-
- dispersion curve
-
- site effects
-
- Published_External
Publication Date
2024-05-23T04:03:10
Creation Date
Security Constraints
Legal Constraints
Status
completed
Purpose
Paper to be submitted to 2023 Australian Earthquake Engineering Society Annual Conference
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Australian Earthquake Engineering Society (AEES) Conference, 23-25 November 2023, Brisbane, QLD
Lineage
Paper to be submitted to 2023 Australian Earthquake Engineering Society Annual Conference
Parent Information
Extents
[-39.2603, -38.2481, 145.6883, 147.3313]
Reference System
Spatial Resolution
Service Information
Associations
Source Information