Authors / CoAuthors
Allen, T. | Ghasemi, H. | Griffin, J.
Abstract
Seismic hazard models, commonly produced through probabilistic seismic hazard analysis, are used to establish earthquake loading requirements for the built environment. However, there is considerable uncertainty in developing seismic hazard models, which require assumptions on seismicity rates and ground-motion models (GMMs) based on the best evidence available to hazard analysts. This paper explores several area-based tests of long-term seismic hazard forecasts for the Australian continent. ShakeMaps are calculated for all earthquakes of MW 4.25 and greater within approximately 200 km of the Australian coastline using the observed seismicity in the past 50 years (1970-2019). A “composite ShakeMap” is generated that extracts the maximum peak ground acceleration “observed” in this 50-year period for any site within the continent. The fractional exceedance area of this composite map is compared with four generations of Australian seismic hazard maps for a 10% probability of exceedance in 50 years (~1/500 annual exceedance probability) developed since 1990. In general, all these seismic hazard models appear to be conservative relative to the observed ground motions that are estimated to have occurred in the last 50 years. To explore aspects of possible prejudice in this study, the variability in ground-motion exceedance was explored using the Next Generation Attenuation-East GMMs developed for the central and eastern United States. The sensitivity of these results is also tested with the interjection of a rare scenario earthquake with an expected regional recurrence of approximately 5,000 - 10,000 years. While these analyses do not provide a robust assessment of the performance of the candidate seismic hazard for any given location, they do provide—to the first order—a guide to the performance of the respective maps at a continental scale. This paper was presented at the Australian Earthquake Engineering Society 2021 Virtual Conference, Nov 25 – 26.
Product Type
document
eCat Id
145963
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
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2601
Australia
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Keywords
- theme.ANZRC Fields of Research.rdf
-
- Natural HazardsEARTH SCIENCESEarthquake Engineering
- ( Discipline )
-
- Earthquake Hazard
- ( Product )
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- ShakeMap
- ( Theme )
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- Ground-motion exceedance
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- seismic hazard maps
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- Published_External
Publication Date
2022-11-10T06:29:31
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completed
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Paper presented at Australian Earthquake Engineering Society 2021 Virtual Conference Paper
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geoscientificInformation
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Based on the 2018 National Seismic Hazard Assessment Paper presented at Australian Earthquake Engineering Society 2021 Virtual Conference Paper
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[-44.00, -9.00, 112.00, 154.00]
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Associations
Association Type - wasInformedBy
The 2018 National Seismic Hazard Assessment: Model overview
eCat Identifier - 123020,
UUID - 9456a1ee-400d-43fa-bce3-58d1cd8cdf55
Association Type - wasInformedBy
The 2018 National Seismic Hazard Assessment for Australia – Data package, maps and grid values
eCat Identifier - 123028,
UUID - 1be4f6be-a3a2-4ec5-b8af-4018f96243be
Association Type - wasInformedBy
The 2018 national seismic hazard assessment of Australia: Quantifying hazard changes and model uncertainties
eCat Identifier - 126324,
UUID - 9d84d182-eb0d-4637-b5cd-580b7da85cde
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