Dan Clark

• PhD
• Earthquake Geologist at Geoscience Australia

Relative to other intraplate areas of theworld,Australia has a short recorded history of seismicity, spanning only a couple of centuries. As a consequence, there is significant uncertainty as to whether patterns evident in the contemporary seismic record are representative of the longer term, or constitute a bias resulting from the short sampling p...

Australia boasts arguably the richest Late Neogene to Quaternary faulting record in stable continental region (SCR) crust anywhere in the world. Variation in fault scarp length, vertical displacement, proximity to other faults and relationship to topography permits division of the continent according to fault character. Six onshore “neotectonic dom...

In plate boundary regions moderate to large earthquakes are often sufficiently frequent that fundamental seismic parameters such as the recurrence intervals of large earthquakes and maximum credible earthquake (Mmax) can be estimated with some degree of confidence. The same is not true for the Stable Continental Regions (SCRs) of the world. Large e...

The Australian continent is actively deforming in response to far-field stresses generated by plate boundary interactions and buoyancy forces associated with mantle dynamics. On the largest scale (several 103 km), the submergence of the northern continental shelf is driven by dynamic topography caused by mantle downwelling along the Indo-Pacific su...

Based on structural, petrographic and geochronological work (SHRIMP zircon, monazite and rutile), the Mesoproterozoic Albany–Fraser Orogeny is divided into two discrete thermo-tectonic stages, between c. 1345 and 1260 Ma (Stage I) and c. 1214 and 1140 Ma (Stage II). The existence of a two-stage history is confirmed by the discovery of 1321±24 Ma de...

Eastern Queensland (Australia) was struck by a major earthquake at ≈04:14 a.m. local time on 7 June 1918. Most previous studies have suggested that the epicenter of this earthquake lies off the coast of Bundaberg, between the port cities of Gladstone and Rockhampton. This epicentral location was based upon instrumental observations from the Rivervi...

A robust record of earthquake activity in any given region is vital to identify regions of elevated seismogenic potential, define seismogenic sources and to help forecast future rates of seismicity. Records of earthquakes predating instrumentation and those occurring while instrumentation was still in its infancy might be used to augment the relati...

Geoscience Australia, together with contributors from the wider Australian seismology community, have produced a new National Seismic Hazard Assessment (NSHA23), recommended for inclusion in proposed updates to Standards Australia's AS1170.4. NSHA23 builds on the model framework developed for NSHA18, and incorporates scientific advances and stakeho...

Dam owners and operators must consider a range of hazards for the design and maintenance of infrastructure assets – including seismic hazards. In 2018, Geoscience Australia completed its National Seismic Hazard Assessment (the NSHA). This assessment used best-practice probabilistic approaches and produced considerably lower hazard forecasts than it...

The 1 March 1954 earthquake in South Australia is the most damaging earthquake to impact the densely populated Adelaide region since European settlement in the state. Previous interpretations of macroseismic data have associated the event with the Eden-Burnside Fault zone, with a presumed epicentre near Darlington. We assessed the validity of this...

Analysis of TanDEM‐X and Shuttle Radar Topography Mission (SRTM) data reveals geomorphic evidence for 292 fault‐propagation fold scarps across the Miocene Nullarbor and Pliocene Roe Plains in south‐central Australia. Vertical displacements (VD) are determined using topographic profiling of a subset (n=48) of the fold traces. Fault dips (mean = 44+1...

The authors would like to correct the published article [...]

Sandstrom et al. (2020) present new elevation and age data for a flight of four marine terraces preserved along the western limb of the Cape Range anticline in western Australia. Their interpretation of these data provides an alternative estimate for the amount of tectonic deformation that has occurred since terrace formation. They conclude that le...

Sandstrom et al. (2020) present new elevation and age data for a flight of four marine terraces preserved along the western limb of the Cape Range anticline in western Australia. Their interpretation of these data provides an alternative estimate for the amount of tectonic deformation that has occurred since terrace formation. They conclude that le...

The 2016 MW 7.8 Kaikōura Earthquake nucleated on The Humps fault, which ruptured across the Emu Plain in North Canterbury. The paleoearthquake history of the fault was poorly constrained prior to the 2016 earthquake. To determine the timing and single-event displacements (SED) of earthquakes on the fault we use Optically Stimulated Luminescence (OS...

The 20th May 2016 MW 6.1 Petermann earthquake in central Australia generated a 21 km surface rupture with 0.1 to 1 m vertical displacements across a low‐relief landscape. No paleo‐scarps or potentially analogous topographic features are evident in pre‐earthquake Worldview 1 and 2 satellite data. Two excavations across the surface rupture expose nea...

Seismicity in the intraplate southwest of Western Australia is poorly understood, despite evidence for potentially damaging earthquakes of magnitude > M6. Identifying stress-focusing geological structures near significant earthquake sequences assists in understanding why these earthquakes occur in seemingly random locations across a region of more...

The 20 May 2016 surface-rupturing intraplate earthquake in the Petermann Ranges is the largest onshore earthquake to occur in the Australian continent in 19 yr. We use in situ and Interferometric Synthetic Aperture Radar surface observations, aftershock distribution, and the fitting of P-wave source spectra to determine source properties of the Pet...

A shallow Mw 5.3 earthquake near Lake Muir in the stable continental region (SCR) crust of southwest Western Australia on the 16 September 2018 was followed on the 8 November by a proximal Mw 5.2 event. Focal mechanisms produced for the events suggest reverse and strike-slip rupture, respectively. Field mapping, guided by Sentinel-1 InSAR data, rev...

Seismic hazard assessments in stable continental regions such as Australia face considerable challenges compared with active tectonic regions. Long earthquake recurrence intervals relative to historical records make forecasting the magnitude, rates, and locations of future earthquakes difficult. Similarly, there are few recordings of strong ground...

Sites recording the extinction or extirpation of tropical–subtropical and cool–cold temperate rainforest genera during the Plio–Pleistocene aridification of Australia are scattered across the continent, with most preserving only partial records from either the Pliocene or Pleistocene. The highland Lake George basin is unique in accumulating sedimen...

We digitize surface rupture maps and compile observational data from 67 publications on ten of eleven historical, surface-rupturing earthquakes in Australia in order to analyze the prevailing characteristics of surface ruptures and other environmental effects in this crystalline basement-dominated intraplate environment. The studied earthquakes occ...

High‐resolution optical satellite imagery is used to quantify vertical surface deformation associated with the intraplate 20 May 2016 Mw 6.0 Petermann Ranges earthquake, Northern Territory, Australia. The 21 ± 1‐km‐long NW trending rupture resulted from reverse motion on a northeast dipping fault. Vertical surface offsets of up to 0.7 ± 0.1m distri...

The 1987 to 2019 Tennant Creek earthquake sequence comprises three 1988 surface-rupturing mainshocks (moment magnitude (Mw 6.2, 6.3, and 6.5) that occurred within a 12-hour period, a preceding foreshock sequence commencing in 1987, and a prolonged aftershock sequence including a Mw 5.0 earthquake on the 1st August 2019. Each surface rupturing event...

Modern geodetic and seismic monitoring tools are enabling the study of moderate-sized earthquake sequences in unprecedented detail. Here we use a variety of methods to examine surface deformation caused by a sequence of earthquakes near Lake Muir in southwest Western Australia in 2018. A shallow MW 5.3 earthquake on the 16th of September 2018 was f...

The 2nd June 1979 moment magnitude (Mw) 6.1 Cadoux earthquake caused a complex, multi-fault surface rupture consisting of six mapped scarps: (from south to north) the 8 km long west dipping Robb scarp, 3 km long south dipping Cumming scarp, the Lone Tree, Carter and Tank scarps (which together define an east-dipping arcuate rupture) and the 2.5 km...

The 14th October 1968 MW 6.6 Meckering earthquake surface rupture is comprised of a main 37 km long concave Meckering scarp (with a 1.5 km wide dextral step-over along the Burges en-echelon rupture complex) and a minor 9 km long rupture on the Meckering scarp foot-wall (the Splinter scarp, also with a 1.5 km dextral step-over). We recommend a total...

The 20th May 2016 Mw 6.1 Petermann earthquake produced a 21 km long surface rupture with a maximum vertical offset of 0.9 m. Geological and geophysical data provide strong evidence that rupture occurred along a mylonite foliation plane with an orientation defined by deformation from the nearby Woodroffe Thrust, a major Neoproterozoic terrane suture...

The 23rd March 2012 Mw 5.2 Pukatja earthquake produced an arcuate surface rupture 1.6 km long with a maximum vertical offset of 0.48 m. We reclassify its length to 1 km based on application of orientation and kinematic criteria used previously to measure other historic Australian surface ruptures. Epicentres are poorly constrained and inaccurate, l...

The 10th March 1970 moment magnitude (Mw) 5.0 Calingiri earthquake surface rupture is 3.3 km long with a maximum vertical displacement of 0.4 m. The fault as defined by surface measurements is a shallow-dipping reverse fault (~ 20° east) with a probable shallow hypocentre (< 1 km). This is consistent with published hypocentral depths, though large...

The 30th March 1986 Mw 5.7 Marryat Creek earthquake produced a highly arcuate 13 km long surface rupture with maximum vertical displacement of 0.9 m. Sinistral displacement on the NE-SW limb, dextral displacement on the NNE-SSW limb, and maximum vertical displacement in the central apex of rupture supports SW over NE movement of a hanging-wall bloc...

The 2018 National Seismic Hazard Assessment (NSHA18) aims to provide the most up-to-date and comprehensive understanding of seismic hazard in Australia. As such, NSHA18 includes a range of alternative models for characterising seismic sources and ground motions proposed by members of the Australia earthquake hazard community. The final hazard asses...

Earthquake Environmental Effects (EEEs) identified in the source region of the 20th May 2016 intraplate moment magnitude (Mw) 6.1 Petermann earthquake in Central Australia are described and classified using the Environmental Seismic Intensity (ESI-07) scale. EEEs include surface rupture, ground fissures and cracks, vegetation damage, rockfalls, and...

Collaborative project between the Geological Survey of Western Australia, Geological Survey of South Australia, Geoscience Australia, ANU, and Auscope.

Unique challenges are faced in modelling faults in intraplate regions for seismic hazard purposes. Low fault slip rates compared to landscape modification rates often leads to poor discoverability of fault sources, and results in incomplete characterisation of rupture behaviour. Regional and local test cases have demonstrated that fault sources ass...

What lies beneath the Nullarbor Plain? Insights into the geology of the Coompana Province from deep crustal seismic reflection profile 13GA-EG1

Geological Interpretation of the Coompana Province section of the Eucla-Gawler Seismic Line (13GA-EG1)

Geological Interpretation of the Madura Province section of the Eucla-Gawler Seismic Line (13GA-EG1)

Plate 1. Geological Interpretation of the Gawler Craton section of the Eucla-Gawler Seismic Line (13GA-EG1E) was compiled by TW Wise (Geological Survey of South Australia) based on interpretations by MP Doublier, RA Dutch, D Clark, MJ Pawley, GL Fraser, TW Wise, BLN Kennett, A Reid, CV Spaggiari, AJ Calvert, S van der Wielen, H. Dulfer, B Bendall,...

The Cadell Fault, found in stable continental region (SCR) crust in southeastern Australia, provides a record of temporally clustered morphogenic earthquakes spanning much of the Cenozoic. The slip rate, averaged over perhaps as many as five complete seismic cycles in the period 70–20 ka, is c. 0.4–0.5 mm a ⁻¹ , compared with an average rate of c....

In probabilistic seismic hazard modelling the choice of whether faults are attributed with Characteristic or Gutenberg-Richter recurrence statistics has a major impact on the calculated hazard level proximal to the faults. Compared to a model that does not include fault sources, the addition of a high slip rate (by intra-plate standards) Characteri...

Our paleoseismological study of faults and fault-related folds comprising the Mount Narryer fault zone reveals a mid-to late Qua-ternary history of repeated morphogenic earthquakes that have influenced the plan-form and course of the Murchison, Roderick, and Sanford Rivers, Western Australia. The dominant style of deformation involves folding of ne...

The Global Earthquake Model (GEM) aims to develop uniform, openly available, standards, datasets and tools for worldwide seismic risk assessment through global collaboration, transparent communication and adapting state-of-the-art science. GEM Faulted Earth (GFE) is one of GEM’s global hazard module projects. This paper describes GFE’s development...

In stable continental regions (SCRs), the process of probabilistic seismic- hazard assessment (PSHA) remains a scientific and technical challenge. In producing a new national hazard model for Australia, we developed several innovative techniques to address these challenges. The Australian seismic catalog is heterogeneous due to the variability bet...

Identifying the influence of neotectonics on the morphology of elevated passive margins is complicated in that major morpho-structural patterns might plausibly be explained by processes related to late Mesozoic to early Cenozoic rifting and/or differential erosion induced by Cenozoic epeirogenic uplift. The proportional contribution of each process...

On 23 March 2012, at 09: 25 UTC, an M-w 5.4 earthquake occurred in the eastern Musgrave Ranges of north-central South Australia, near the community of Ernabella (Pukatja). Several small communities in this remote part of central Australia reported the tremor, but there were no reports of injury or significant damage. This was the largest earthquake...

Alignment of northwestern Australia's passive margin with the terminations of the eastern Java trench and western Banda arc has triggered a new phase of reactivation along the Phanerozoic North West Shelf rift system. Dextral faulting in Browse basin cross-cuts Middle to Late Miocene inversion structures and offsets the seafloor. Similarities in di...

Tectonic geomorphology along the continental margin of Western Australia indicates the presence of an approximately 2000 km long zone of dextral-oblique neotectonic faults and folds referred to as the Western Australian shear zone (WASZ). The WASZ reoccupies older rift related structures that initially formed during periods of continental-scale fra...

A trench was excavated across the southeastern Reelfoot rift margin for paleoseismic research purposes and for the 2011 Seismological Society of America national meeting field trip. The trench was parallel to and 6 m southwest of the Oldham trench described in 2006. In this 2011 trench, faulted alluvial fan stratigraphy and liquefaction deposits le...

At 09:25 GMT, a M W 5.4 earthquake occurred in the eastern Musgrave Ranges of north-central South Australia, near the community of Ernabella (Pukatja) (Figure 1). Several small communities in this remote part of central Australia reported the tremor, but there were no reports of injury or significant damage. This was the largest earthquake recorded...

Introduction Australia is classified as a Stable Continental Region (SCR) in terms of its plate tectonic setting and seismicity (Johnston et al. 1994). While such settings produce only approximately 0.2% of the world's seismic moment release, large and potentially damaging earthquakes are not uncommon (e.g. Crone et al. 1997). In the last four deca...

Australia boasts arguably the richest Quaternary faulting record in all of the world's stable continental region (SCR) crust. Variation in Quaternary fault scarp length, vertical displacement, relation to other faults and to topography, justifies the division of the continent according to fault character. Six onshore "neotectonic domains" are recog...

We present a preliminary probabilistic seismic hazard analysis (PSHA) of a site in the Otway basin, Victoria, Australia, as part of the CO2CRC Otway Project for CO(2) storage risk. The study involves estimating the likelihood of future strong earthquake shaking at the site and utilizes three datasets: (1) active faults, (2) historical seismicity, a...

New paleoseismic studies have been undertaken on the Wellington-Hutt Valley (W-HV) segment of the Wellington fault to characterize its late Holocene record of surface-rupturing earthquakes. Trenches and radiocarbon dates from Te Kopahou and Te Marua have provided evidence and improved timing for the four most recent earthquake ruptures. These event...

The ∼900 km long Darling Scarp in Western Australia is one of the most prominent linear topographic features on Earth. Despite the presence of over-steepened reaches in all westerly flowing streams crossing the scarp, and significant seismic activity within 100 km of the scarp, there is no historical seismicity and no reported evidence for Quaterna...

Geoscience Australia (GA) is currently undertaking a process of revising the Australian National Earthquake Hazard Map using modern methods and an updated catalogue of Australian earthquakes. This map is a key component of Australia's earthquake loading standard, AS1170.4. Here we present an overview of work being undertaken within the GA Earthquak...

Australia’s rich neotectonic record provides an opportunity to better understand the characteristics of seismogenic intraplate deformation, both at the scale of a single fault and at the scale of the entire continent. Over the last decade knowledge of Australian intraplate faults has advanced significantly. Herein we review this knowledge and propo...

An examination of regionally extensive hill-shaded Shuttle Radar Topography Mission (SRTM) 90 m resolution and Department of Land Information (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 38 previously unrecognized linear t...

The tectonic origin, palaeoearthquake histories and slip rates during the last c. 26 ka have been examined for six normal faults (referred to here as the Rahotu, Oaonui, Kina, Ihaia, Kiri and Pihama faults) within the Taranaki Rift, New Zealand. A minimum of 13 ground-surface rupturing palaeoearthquakes have been recognised on four of the faults us...

The Australian continent is actively deforming at a range of scales in response to far-field stresses associated with plate margins and buoyancy forces associated with mantle dynamics. On the smallest scale (10 1 km), fault-related deformation associated with far-field stress partitioning has modified surface topography at rates of up to ~100 m per...

The southwest seismic zone is a region of concentrated intra-plate seismicity in the southwest of Western Australia. The regional geology consists of Archean granitoids covered by a thick, electrically conductive, mantle of in situ weathered material and transported cover. Numerous palaeofault scarps have been recognised in the region, primarily ba...

The Australian continent is actively deforming at a range of scales in response to far-field stresses associated with plate margins, and buoyancy forces associated with mantle dynamics. On the smallest scale (several 10's of km), fault-related deformation associated with far-field stress partitioning has modified surface topography at rates of up t...

The inventory of over 200 fault scarps captured in GA's Australian neotectonics database, comprising both probable and proven palaeo-earthquake sources, has been used to produce preliminary estimates of the maximum credible magnitude earthquake (Mmax) across the Stable Continental Regions (SCRs) of Australia. This was done by first grouping the sca...

Occurring in the southwest of Western Australia, the 1968 Meckering earthquake (MS 6.8) resulted in the formation of an extensive surface rupture complex comprising faults with a range of orientations and reverse and dextral lateral offsets. Modeling of the seismological characteristics of the source showed that reverse failure occurred on a north–...

A neotectonic fault is defined as one that has hosted measurable displacement in the current crustal stress regime (i.e. within the last 5-10 Ma (Sandiford et al. 2004)), and is therefore suitably oriented to host (or is capable of hosting) future displacement (Machette 2000). Evidence for palaeo-seismicity on a suspected neotectonic fault, potenti...

The Sydney Basin encloses a significant proportion of the Australian population, and the 1989 M5.6 Newcastle earthquake demonstrated that the basin is not immune from the impact of even relatively modest earthquakes. In spite of this, few investigations have been conducted to identify and characterise potential geologic sources of strong ground sha...

The Lapstone Structural Complex (LSC) comprises a series of major faults and monoclinal flexures that form the eastern margin of the Blue Mountains Plateau, an area of elevated topography west of the Sydney Basin (Branagan and Pedram, 1990). The LSC is located within the Southeast Australian highlands, one of the most seismically active areas of Au...

As part of the seismic hazard study for the Otway Carbon Capture and Storage Project, GNS Science requested data on potential neotectonic faults within 200 km of the site. The attached is the datafile provided to GNS.

We present new paleoseismicity data for the 30 km long and 2.5 m high Hyden fault scarp in Western Australia, which, when combined with the results of previous research, provides the most extensive record of surface-rupturing earthquakes yet assembled for an ‘active’ Australian intracratonic fault. The data indicate that four to five surface-ruptur...