Paleoseismic Evidence for 3-5 Earthquakes on the Southern Willunga Fault, South Australia

Preliminary results from a paleoseismic investigation of the southern Willunga Fault, approximately 40 km south of Adelaide, presented at the 2022 ANZGG Conference. 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. The dataset, associated with the Australian Ocean Data Network, aims to constrain the timing of these events to better understand present-day seismic hazard.

Use Cases

• Modeling seismic hazard for communities near Adelaide based on estimated earthquake recurrence and displacement.
• Reconstructing the uplift history of the Mount Lofty Ranges based on evidence from fault trenches.
• Calibrating long-term tectonic models using the relationship between recent earthquakes and uplifted Pliocene basins.
• Dating the timing of paleo-earthquakes based on samples collected from excavated trenches.

Strengths

• Provides quantitative displacement estimates of 0.5 – 1.7 meters per earthquake event.
• Identifies evidence for 3-5 distinct ground-rupturing earthquakes.
• Focuses on a specific fault segment (~40 km south of Adelaide) with direct relevance to proximal communities.

Limitations

• Data is described as preliminary results; final analyses may differ.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

Australian Ocean Data Network

Collection Method

Paleoseismic investigation involving trench excavation across the fault to examine fault planes and sedimentary strata.

Time Range

Middle to Late Pleistocene to present

Freshness

Last updated 2026-06-27 16:00:25.870053; freshness should be verified.

Geography

Southern Willunga Fault, Mount Lofty Ranges, approximately 40 km south of Adelaide, South Australia