Identification of Quaternary scarps in southwest and central west Western Australia using DEM-based hill shading: application to seismic hazard assessment and neotectonics  

Authors / CoAuthors

Clark, D.J.

Abstract

An examination of regionally extensive hill-shaded SRTM 90m resolution and DLI 10 m resolution digital elevation data and discussions with government and industry geologists familiar with the local geology has resulted in the identification of thirty eight previously unrecognised linear topographic scarps in the southwest and central west of Western Australia. I contend that most of these relate to Quaternary surface-rupturing earthquakes. If validated, this more than doubles the number of Quaternary fault scarps known from this area, bringing the total to sixty. The newly recognised scarps average between 25 km and 50 km in length and from ~1.5 m to 20 m in height. The geometric, recurrence and spatial attributes of these features makes it possible to propose a model describing the causative seismicity. The model contends that uniform contractional strain in the ductile lithosphere manifests as localised, transient and recurrent brittle deformation in zones of pre-existing crustal weakness in the upper lithosphere. The data presented allow for ready calculation of the maximum probable magnitude earthquake for the southwest of Western Australia, and identify 'earthquake prone' regions of interest to seismic hazard assessors.

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nonGeographicDataset

eCat Id

70070

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Keywords

• External PublicationScientific Journal Paper

( Theme )

• earthquakes

( Theme )

• geomorphology

( Theme )

• DEM

• AU-WA

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_Internal

Publication Date

2010-01-01T00:00:00

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Australian Government Security ClassificationSystem    

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Creative Commons Attribution 4.0 International Licence    

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unknown

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geoscientificInformation

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Unknown

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[-36.0, -26.0, 114.0, 124.0]

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Spatial Resolution

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