Recognising intraplate seismogenic faults and associated seismic hazard: examples from Western Australia

Research output: Chapter in Book/Conference paperConference paperpeer-review

Abstract

The location of past earthquake activity is a parameter required in assessments of seismic hazard. In intraplate regions such as Western Australia (WA), establishing the characteristics and location of past seismicity is difficult due to: (i) the long recurrence intervals between large events (ii) the subtle nature of the earthquake activity surface expression and (iii) the potential occurrence of earthquakes over vast areas (with unclear tectonic mechanisms).
In recent years, various tools have been used to improve the understanding of past earthquake activity in WA, placing emphasis on recognising and characterising potentially seismogenic faults. These tools include:
analysis of digital elevation models (DEMs) to recognise fault scarp morphology,
analysis of tectonic geomorphology associated with potential fault scarps, drainage analysis to infer tectonic deformation and use of shallow geophysical surveys such as GPR and magnetic surveys to confirm faulting and geological context.
The above, relatively inexpensive, tools are used to recognise potentially seismogenic faults before carrying out paleoseismologial studies, which are expensive and time consuming.
Applying these tools resulted in the recognition of tens of potentially seismogenic scarps across WA. Here we describe work on two fault scarps that have been analysed in this fashion: the Lort River Fault and the newly recognised Dumbleyung Fault. The evidence exposed by trenching of thee structures during the paleoseismological investigations confirmed their association with faulting and revealed their recent earthquake history. Both structures show recurrent earthquakes, separated by thousands of years, with magnitudes up to 7.0.
Original languageEnglish
Title of host publicationProceedings of the 10th Pacific Conference on Earthquake Engineering
Place of PublicationAustralia
PublisherAustralian Earthquake Engineering Society
Number of pages11
Publication statusPublished - 6 Nov 2015
Event10th Pacific Conference on Earthquake Engineering: Building an Earthquake -Resilient Pacific - Sydney, Australia
Duration: 6 Nov 20158 Nov 2015

Conference

Conference10th Pacific Conference on Earthquake Engineering
Country/TerritoryAustralia
CitySydney
Period6/11/158/11/15

Fingerprint

Dive into the research topics of 'Recognising intraplate seismogenic faults and associated seismic hazard: examples from Western Australia'. Together they form a unique fingerprint.

Cite this