Authors / CoAuthors
Allen, T. | Seismological Society of America
Abstract
At its nearest, northern Australia is just over 400 km from an active convergent plate margin. This complex and unique tectonic region combines active subduction and the collision of the Sunda-Banda Arc with the Precambrian North Australian Craton (NAC) near the Timor Trough and continues through to the New Guinea Highlands. Ground-motions generated from earthquakes on these structures have particular significance for northern Australian communities and infrastructure projects, with several large earthquakes in the Banda Arc region having caused ground-shaking-related damage in the northern Australian city of Darwin over the historical period. There are very few, if any, present-day tectonic analogs where cold cratonic crust abuts a convergent tectonic margin with subduction and continent-continent collision. Ground motions recorded from earthquakes in typical subduction environments are highly attenuated as they travel through young sediments associated with forearc accretionary prisms and volcanic back-arc regions. In contrast, seismic energy from earthquakes in the northern Australian plate margin region are efficiently channelled through the low-attenuation NAC, which acts as a waveguide for high-frequency earthquake shaking. As such, it is difficult to select models appropriate to the region for seismic hazard assessments. The development of a far-field ground-motion model to support future seismic hazard assessments for northern Australia is discussed. In general, the new model predicts larger ground motions in Australia from plate margin sources than models used for the 2018 National Seismic Hazard Assessment of Australia, none of which were considered fully appropriate for the tectonic environment. Short-period ground motions are strongly dependent on hypocentral depth and are significantly higher than predictions from commonly-used intraslab ground-motion models at comparable distances. The depth dependence in ground motion diminishes with increasing spectra periods. <b>Cite this article as</b> Allen, T. I. (2021). A Far-Field Ground-Motion Model for the North Australian Craton from Plate-Margin Earthquakes, <i>Bull. Seismol. Soc. Am. </i><b> 112</b>, 1041–1059, doi: 10.1785/0120210191
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document
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133037
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- theme.ANZRC Fields of Research.rdf
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- Natural HazardsSeismology and Seismic ExplorationEARTH SCIENCESEarthquake Engineering
- ( Theme )
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- Ground-motion attenuation
- ( Discipline )
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- Earthquake Hazard
- ( Theme )
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- North Australian Craton
- ( Theme )
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- Banda Sea
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2022-11-10T06:29:32
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This article was written for Submission to the "Bulletin of the Seismological Society of America" journal 2021
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Bulletin of Earthquake Engineering (2022) Volume 112 Number 2 1041-1059
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This article was written and submitted to the "Bulletin of the Seismological Society of America" journal in 2021, Published in 2022.
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[-24.00, -4.00, 120.00, 150.00]
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