Large earthquake recurrence on the southern Willunga Fault, South Australia  


Authors / CoAuthors

Clark, D. | Griffin, J. | La Greca, J. | Quigley, M. | Sellmann, S. | Ninis, D. | Kuang, K. | Wilson, A.

Abstract

<div>The presence of Pliocene marine sediments in the Myponga and Meadows basins within the Mt Lofty Ranges south of Adelaide is testament to over 200&nbsp;m of tectonic uplift within the last 5 Myr (e.g., Sandiford 2003, Clark 2014). The spatiotemporal distribution of uplift amongst the various faults within the range and along the range fronts is poorly understood. Consequently, large uncertainties are associated with estimates of the hazard that the faults pose to proximal communities and infrastructure.</div><div>&nbsp;</div><div>We present the preliminary results of a paleoseismic investigation of the southern Willunga Fault, ~40 km south of Adelaide. Trenches were excavated across the fault to examine the relationships between fault planes and sedimentary strata. Evidence is preserved for 3-5 ground-rupturing earthquakes since the Middle to Late Pleistocene, with single event displacements of 0.5 – 1.7 m. Dating of samples will provide age constraints on the timing of these earthquakes. This most recent part of the uplift history may then be related to the longer-term landscape evolution evidenced by the uplifted basins, providing an enhanced understanding of the present-day seismic hazard.</div> This abstract was presented at the Australian & NZ Geomorphology Group (ANZGG) Conference in Alice Springs 26-30 September 2022. https://www.anzgg.org/images/ANZGG_2022_First_circular_Final_V3.pdf

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document

eCat Id

147006

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Commonwealth of Australia (Geoscience Australia)  
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

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Keywords

( Project )
  • Earthquake activity
  • earthquake hazard
  • seismic hazard
  • tectonics
theme.ANZRC Fields of Research.rdf
  • Structural geology and tectonics
  • Published_External

Publication Date

2022-10-13T00:32:31

Creation Date

2022-07-06T16:00:00

Security Constraints

Australian Government Security Classification System    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Use - license otherRestrictions

Status

completed

Purpose

This abstract will be presented as a talk at the conference with the purpose of stimulating thought and discussion on Australian tectonic geomorphology and earthquake hazard.

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asNeeded

Topic Category

geoscientificInformation

Series Information

Lineage

This abstract was created to present at the Australian & NZ Geomorphology Group (ANZGG) Conference in Alice Springs 26-30 September 2022. https://www.anzgg.org/images/ANZGG_2022_First_circular_Final_V3.pdf

Parent Information

Extents

[-54.75, -9.2402, 112.92, 159.11]

Reference System

Spatial Resolution

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Download Abstract (pdf) [168.6]  

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