Paleoseismic Investigation of Southern Willunga Fault Earthquakes

Paleoseismic evidence spanning the Middle to Late Pleistocene documents 3-5 ground-rupturing earthquakes on the southern Willunga Fault. The dataset includes measurements of single-event displacements ranging from 0.5 to 1.7 meters. This investigation was presented by the Australian Ocean Data Network at the 2022 Australian & NZ Geomorphology Group Conference.

Use Cases

• Model fault slip rates and recurrence intervals using the count of 3-5 earthquakes and displacement measurements of 0.5–1.7 m.
• Calibrate regional seismic hazard maps by integrating the paleoseismic event history from trench excavations.
• Correlate short-term fault activity with long-term tectonic uplift evidenced by Pliocene marine sediment data.
• Estimate maximum probable earthquake magnitudes based on documented single-event displacement ranges.

Strengths

• Evidence for 3-5 distinct paleoearthquake events.
• Quantified single-event displacement range of 0.5 to 1.7 meters.
• Investigation focused on a specific fault segment ~40 km south of Adelaide.

Limitations

• Sample data and specific column schema are unavailable.
• Dataset is a conference abstract; detailed trench logs and raw dating samples may not be included.
• Temporal coverage for events is broadly defined as Middle to Late Pleistocene without precise dates.

Provenance

Source

Australian Ocean Data Network, presented at the Australian & NZ Geomorphology Group Conference.

Collection Method

Paleoseismic trench excavation across the fault to examine fault plane and sedimentary stratum relationships.

Time Range

Middle to Late Pleistocene (spanning the last ~5 million years of uplift history).

Freshness

null

Geography

Southern Willunga Fault, approximately 40 km south of Adelaide, South Australia.