Authors / CoAuthors
Allen, T.I.
Abstract
Geoscience Australia has produced a draft National Seismic Hazard Assessment (NSHA18), together with contributions from the wider Australian seismology community. This paper provides an overview of the provisional peak ground acceleration (PGA) hazard values and discusses rationale for changes in the proposed design values at the 1/500-year annual exceedance probability (AEP) level relative to Standards Australia’s AS1170.4–2007 design maps. The NSHA18 update yields many important advances on its predecessors, including: consistent expression of earthquake magnitudes in moment magnitude; inclusion of epistemic uncertainty through the use of third-party source models; inclusion of a national fault-source model; inclusion of epistemic uncertainty on fault-slip-model magnitude-frequency distributions and earthquake clustering; and the use of modern ground-motion models through a weighted logic tree framework. In general, the 1/500-year AEP seismic hazard values across Australia have decreased relative to the earthquake hazard factors the AS1170.4–2007, in most localities significantly. The key reasons for the decrease in seismic hazard factors are due to: the reduction in the rates of moderate-to-large earthquakes through revision of earthquake magnitudes; the increase in b-values through the conversion of local magnitudes to moment magnitudes, particularly in eastern Australia, and; the use of modern ground-motion attenuation models. Whilst the seismic hazard is generally lower than in the present standard, we observe that the relative proportion of the Australian landmass exceeding given PGA thresholds is consistent with other national hazard models for stable continental regions.
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document
eCat Id
135795
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
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Keywords
- ( Theme )
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- seismic hazard
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- AS1170.4
- theme.ANZRC Fields of Research.rdf
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- EARTH SCIENCES
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- Published_External
Publication Date
2020-09-22T02:20:46
Creation Date
2018-03-01T12:00:00
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completed
Purpose
Extended abstract for the Australian Earthquake Engineering Society 2017 Conference
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asNeeded
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geoscientificInformation
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Extended abstract for Australian Earthquake Engineering Society 2017 Conference, Nov 24-26, Canberra, ACT
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[-44.00, -9.00, 154.00, 112.00]
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Spatial Resolution
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