Enhanced intraplate seismicity along continental margins: Some causes and consequences

Sandiford, Mike; Egholm, David Lundbek

doi:10.1016/j.tecto.2008.06.004

Cited by 43 publications

(28 citation statements)

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“…Less well understood are the factors responsible for localizing intraplate seismicity and deformation [ Hillis et al ., ], a phenomenon that is responsible for the creation of numerous landforms found within continental interiors. There is much conjecture as to why concentrations of intraplate events occur, although most hypotheses focus on the role of mechanically (e.g., faults, shear zones, failed rift, flexural deformation) and/or thermally (e.g., high heat flows, volcanic processes) induced weakness of the lithosphere [ Sykes , ; Sandiford , ; Holford et al ., ; Assumpção and Sacek , ]. As well as helping to shed light on these matters, the study of intraplate earthquakes is also important for understanding the associated seismic hazard, which can be significant; e.g., the New Madrid seismic zone, Missouri, experienced three M >7 earthquakes in 1811–1812 [ Tuttle et al ., ], while more recently, a 7.6 M w earthquake occurred in the region of Gujarat, India, in January 2001 [ Negishi et al ., ; Bodin and Horton , ].…”

Section: Introductionmentioning

confidence: 99%

Structural controls on localized intraplate deformation and seismicity in Southern Australia: Insights from local earthquake tomography of the Flinders Ranges

et al. 2013

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Data from an array of 24 seismometers are used to image the crust beneath the Flinders Ranges, southeast Australia, with the goal of improving our understanding of crustal structure, rheology, and the mechanism responsible for the localized intraplate deformation that characterizes this region. A subset of P‐ and S‐wave traveltimes is inverted to jointly recover earthquake hypocenters, P‐wave velocity structure and vp/vs anomalies. The P‐wave velocity model reveals a spatial correlation between major negative velocity perturbations and concentrations of seismicity. In particular, a cluster of seismicity is observed within a distinct low velocity region between the Archean‐Mesoproterozoic Gawler Craton and the Palaeo‐Mesoproterozoic Curnamona Province, from 7 to 20 km depth. We postulate that this may be associated with a pre‐existing structural weakness in the crust that arises primarily from rifting between the Curnamona Province and the Gawler Craton. Another area characterized by a high level of seismicity overlies a major sequence of N‐S trending Ross‐Delamerian thrust faults, which correspond to a band of low vp and particularly vp/vs. The lack of evidence for elevated heat flows in both of these seismogenic regions suggests that thermally induced weakness is unlikely to play a dominant role. Instead, the dynamic behavior of this intraplate region appears to be caused by a serendipitously oriented regional stress field, provided by far field forces that originate from the boundary between the Pacific and Australian plates, which acts upon preexisting structural weaknesses in the lithosphere.

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Section: Introductionmentioning

confidence: 99%

Structural controls on localized intraplate deformation and seismicity in Southern Australia: Insights from local earthquake tomography of the Flinders Ranges

et al. 2013

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“…One class of intraplate seismicity is concentrated along passive continental margins (Sandiford and Egholm, 2008), whereas another comprises events that are scattered heterogeneously throughout the stable continental interior (Basham et al, 1977;Dewey, 1988;Adams, 1989a;Adams and Basham, 1990;Johnston and Kanter, 1990;Hasegawa, 1991;Denith and Featherstone, 2003). Our present work focuses on the latter class of intraplate earthquakes, which are less well understood.…”

Section: Intraplate Seismicity Of Canadamentioning

confidence: 99%

“…This class of seismicity has been extensively studied in recent decades (Gregersen, 1979;Adams and Basham, 1990;Johnston and Kanter, 1990;Denith and Featherstone, 2003;Sandiford and Egholm, 2008; Correspondence to: K. Vasudevan (vasudeva@ucalgary.ca) Liu, 2009) and continues to draw the interest of seismologists and seismic hazard analysts, including earthquakes in the continental interior of the US (Coppersmith et al, 1987;Dewey, 1988;Johnston and Kanter, 1990;Zoback, 1992;Li et al, 2009;Stein and Liu, 2009), several regions of Canada (Basham et al, 1977;Quinlan, 1984;Adams, 1989a;Bent, 1996;Eaton et al, 2005;Darbyshire et al, 2007;Wang et al, 2008;Woodgold, 2010), Australia (Bowman et al, 1990;Denith and Featherstone, 2003;Sandiford and Egholm, 2008), southeast Brazil (Assumpção et al, 2004), and northern Norway (Gregersen, 1979;Atakan et al, 1994;Bungum et al, 2010;Gregersen and Voss, 2009). One particularly intriguing aspect is the high spatial and temporal variability of seismic activity in continental interiors compared with plate boundaries .…”

Section: Introductionmentioning

confidence: 99%

“…One particularly intriguing aspect is the high spatial and temporal variability of seismic activity in continental interiors compared with plate boundaries . Glacial Isostatic Adjustment (GIA) (Quinlan, 1984;Adams, 1989b;Atakan et al, 1994;Wu and Hasegawa, 1996;Wu, 1999;Wu and Johnston, 2000;Ma et al, 2008;Wang et al, 2008;Wu et al, 2010), hotspot tracks (Ma and Eaton, 2006), localized high strain-rates because of thermal fluctuations in the lower crust (Sandiford and Egholm, 2008), and reactivation of ancient terrane boundaries (Hasegawa, 1991;Denith and Featherstone, 2003) have been invoked as possible causative factors for earthquakes in these regions.…”

Section: Introductionmentioning

confidence: 99%

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Intraplate seismicity in Canada: a graph theoretic approach to data analysis and interpretation

Vasudevan

Eaton

Davidsen

2010

Nonlin. Processes Geophys.

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Abstract. Intraplate seismicity occurs in central and northern Canada, but the underlying origin and dynamics remain poorly understood. Here, we apply a graph theoretic approach to characterize the statistical structure of spatiotemporal clustering exhibited by intraplate seismicity, a direct consequence of the underlying nonlinear dynamics. Using a recently proposed definition of "recurrences" based on record breaking processes (Davidsen et al., 2006 , with attributes drawn from the location, origin time and the magnitude of the events. Based on comparisons with a null model derived from Poisson distribution or Monte Carlo shuffling of the catalogue data, our results provide strong evidence in support of spatiotemporal correlations of seismicity in all three regions considered. Similar evidence for spatiotemporal clustering has been documented using seismicity catalogues for southern California, suggesting possible similarities in underlying earthquake dynamics of both regions despite huge differences in the variability of seismic activity.

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“…It is apparent that both the short-term (i.e. seismicity) and longer-term deformation along the margin appears to be localised into a number of discrete domains, suggesting that there are additional controls that govern the spatial distribution of fault initiation and reactivation (Hillis et al, 2008;Leonard, 2008;Sandiford and Egholm, 2008). For example, whereas the Otway and Gippsland basins in southeastern Australia are characterised by a relatively highdensity of post-breakup structures and high seismicity (Fig.…”

Section: Controls On the Localisation Of Deformationmentioning

confidence: 99%

Cenozoic post-breakup compressional deformation and exhumation of the southern Australian margin

Holford

Hillis²,

Duddy³

et al. 2011

The APPEA Journal

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We present results from a margin-wide analysis of the history of post-breakup Cenozoic compressional deformation and related exhumation along the passive southern margin of Australia based on a regional synthesis of seismic, stratigraphic and thermochronological data. The Cenozoic sedimentary record of the southern margin contains regional unconformities of intraLutetian and late Miocene-Pliocene age, which coincide with reconfigurations of the boundaries of the Indo-Australian Plate. Seismic data show that post-breakup compressional deformation and sedimentary basin inversion, characterised by reactivation of syn-rift faults and folding of post-rift sediments, is pervasive from the Gulf St Vincent to Gippsland basins, and occurred almost continually since the early-to-mid Eocene. Inversion structures are absent from the Bight Basin which we interpret to be the result of both the unsuitable orientation of faults for reactivation with respect to post-breakup stress fields, and the colder, stronger lithosphere that underlies that part of the margin. Compressional deformation along the southeastern margin has mainly been accommodated by reactivation of syn-rift faults resulting in folds with varying ages and amplitudes within the post-rift Cenozoic succession. Many hydrocarbon fields in the Otway and Gippsland basins are located within these folds, the largest of which are often associated with substantial localised exhumation. Our results emphasise the importance of constraining the timing of Cenozoic compression and exhumation in defining hydrocarbon prospectivity of the southern margin.

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Enhanced intraplate seismicity along continental margins: Some causes and consequences

Cited by 43 publications

References 50 publications

Structural controls on localized intraplate deformation and seismicity in Southern Australia: Insights from local earthquake tomography of the Flinders Ranges

Structural controls on localized intraplate deformation and seismicity in Southern Australia: Insights from local earthquake tomography of the Flinders Ranges

Intraplate seismicity in Canada: a graph theoretic approach to data analysis and interpretation

Cenozoic post-breakup compressional deformation and exhumation of the southern Australian margin

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