Product catalogue
Hypocenter, Fault Plane, and Rupture Characterization of Australian Earthquakes: Application to the September 2021 Mw 5.9 Woods Point Earthquake
<div>The Australian Seismometers in Schools (AuSIS) network operates 50 broadband seismic stations across Australia that are hosted at schools. The instruments augment the Australian National Seismograph Network providing valuable data from urban and regional Australia. The network coverage is quite sparse, but these vital records of rare, moderate Australian earthquakes can improve our understanding of the deformation within the stable-continental region of Australia, especially for events with no surface rupture. In this study, we present the feasibility of identifying the fault plane of moderate earthquakes on the Australian continent, using data from the AuSIS network. We examine the fault plane of the September 2021, MW 5.9 Woods Point earthquake that occurred about 130 km northeast of the Melbourne metropolitan area. We estimate the hypocenter and the centroid-moment-tensor to identify the fault plane from the auxiliary plane in the focal mechanism. We explore a range of 1D models and a 3D Earth model to simulate seismic arrivals and full waveform data. The hypocenter is resolved using P and S-wave arrivals in a probabilistic framework and the centroid-moment-tensor is derived from full waveform modelling through grid search over a set of trial points around the hypocenter. Our solution suggests the main shock ruptured the depth of 15±4 km, with a strike-slip mechanism striking 348º North on a nearly vertical plane. The high double-couple (DC) percentage of this event indicates a simple rupture that propagated from the south (hypocenter) toward the north (centroid) and remained subsurface with no surface exposure. This indicates that the causative fault had a deeper structure than the previously known shallow, NW-SE striking faults of the region. The P- and T-axis deduced from our fault model are notably aligned with the maximum horizontal crustal stress in the region.</div>
<b>Citation:</b> Sima Mousavi, Babak Hejrani, Meghan S. Miller, Michelle Salmon; Hypocenter, Fault Plane, and Rupture Characterization of Australian Earthquakes: Application to the September 2021 M<sub> w</sub> 5.9 Woods Point Earthquake. <i>Seismological Research Letters</i> 2023;; 94 (4): 1761–1774. doi: https://doi.org/10.1785/0220220348
Simple
Identification info
- Date (Creation)
- 2022-10-22T01:00:00
- Date (Publication)
- 2024-02-14T02:11:11
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/147319
- Cited responsible party
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Role Organisation / Individual Name Details Author Mousavi, S.
External Contact Author Hejrani, B.
Internal Contact Author Miller, M.
External Contact Author Salmon, M.
External Contact Publisher Seismological Society of America
External Contact
- Name
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Seismological Research Letters
- Issue identification
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Volume 94 Number 4 July 2023
- Page
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1761-1774
- Purpose
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In passive seismic imaging methods, the seismic source characteristics and the Earth structure are both unknown. Consequently, both 'source' and 'structure' have to be estimated in an inversion process, which is computationally expensive and very complex. Often, assumptions are made, like the simplifications we assume in the ambient noise tomography. However, for waveform modeling, prior knowledge of the seismic source is essential. In this regard, understanding of the mechanism and dynamic of the rare Australian earthquakes are very useful. I have contributed to such studies before, and I have developed source inversion codes as a researcher at ANU. In this study, the source characteristic of the 2021 Melbourne earthquake is resolved using data from AuSIS and ANSN networks. Results of such studies will be used for surface wave modelling and full waveform inversion in the Passive seismic activity.
- Status
- Completed
- Point of contact
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Role Organisation / Individual Name Details Resource provider Minerals, Energy and Groundwater Division
External Contact Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Hejrani, B.
Internal Contact
- Spatial representation type
- Topic category
-
- Geoscientific information
Extent
))
- Maintenance and update frequency
- Not planned
Resource format
- Title
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Product data repository: Various Formats
- Website
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Data Store directory containing the digital product files
Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes
- Keywords
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Seismology
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- Keywords
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waveform modeling
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- Keywords
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Australian earthquakes
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- theme.ANZRC Fields of Research.rdf
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Seismology and Seismic Exploration
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- Keywords
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Published_External
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Resource constraints
- Title
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Creative Commons Attribution 4.0 International Licence
- Alternate title
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CC-BY
- Edition
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4.0
- Addressee
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Role Organisation / Individual Name Details User Any
- Use constraints
- License
- Use constraints
- License
- Other constraints
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© Seismological Society of America 2023
Resource constraints
- Title
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Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
- Classification system
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Australian Government Security Classification System
- Language
- English
- Character encoding
- UTF8
Distribution Information
- Distributor contact
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Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
Voice facsimile
- OnLine resource
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Link to Journal
Link to Journal
- Distribution format
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Resource lineage
- Statement
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<div>This is a manuscript on the 2021 Melbourne earthquake to be submitted to peer-reviewed international journals. </div><div>The project was led by Sima Mousavi from ANU.</div><div><br></div><div>I provided the computer code to simulate seismic waves in 3D medium and to perform inversion for seismic source.</div><div><br></div>
Metadata constraints
- Title
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Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
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urn:uuid/1db16446-5201-4531-8c5b-09bdfa5a27fc
- Title
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GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Hejrani, B.
Internal Contact
Type of resource
- Resource scope
- Document
- Name
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Journal Article / Conference Paper
Alternative metadata reference
- Title
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Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/147319
- Date info (Creation)
- 2024-02-14T01:55:11
- Date info (Revision)
- 2024-02-14T01:55:11
Metadata standard
- Title
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AU/NZS ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-3
- Title
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Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
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Version 2.0, September 2018
- Citation identifier
- http://pid.geoscience.gov.au/dataset/ga/122551