New geophysical compilations link crustal block motion to Jurassic extension and strike-slip faulting in the Weddell Sea Rift System of West Antarctica

Jordan, Tom A.; Ferraccioli, Fausto; Leat, P. T.

doi:10.1016/j.gr.2016.09.009

Cited by 65 publications

(87 citation statements)

References 121 publications

(217 reference statements)

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“…We model crust ∼35-40 km thick beneath the Haag Nunataks and northern Ellsworth Mountains decreasing to a thickness of ∼30-32 km beneath the Whitmore Mountains (Figures 10 and 11). These thickness estimates and their spatial variation are consistent with aerogravity and receiver function studies (e.g., Chaput et al, 2014;Jordan et al, 2010;Ramirez et al, 2017) and the recognition of distinct structural domains within the composite HEW block (e.g., Jordan et al, 2017;Storey & Dalziel, 1987). While the lateral variation patterns are consistent, Shen et al (2018) model slightly thicker crust at ∼40-44 km beneath the Haag Nunataks and northern Ellsworth Mountains ( Figure S6).…”

Section: Tectonic Interpretation Of V Sv Modelsupporting

confidence: 85%

“…Seismic refraction (Leitchenkov & Kudryavtzev, ) and gravity and magnetic data (Jordan et al, ; Jordan et al, ) suggest the presence of extensive underplating at the base of the crust in the Weddell Sea Rift System, which Jordan et al () attribute to plume‐related Jurassic magmatism. O'Donnell et al () suggest that a subcrustal high shear wave velocity anomaly underlying the southern Weddell Sea Rift System might reflect depleted mantle lithosphere following the extraction of voluminous melt related to Gondwana breakup, that is, a fossil proto‐Weddell plume signature.…”

Section: Shear Wave (Vsv) Velocity Modelmentioning

confidence: 99%

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Mapping Crustal Shear Wave Velocity Structure and Radial Anisotropy Beneath West Antarctica Using Seismic Ambient Noise

O’Donnell

Brisbourne

Stuart

et al. 2019

Geochem Geophys Geosyst

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Using 8‐ to 25‐s‐period Rayleigh and Love wave phase velocity dispersion data extracted from seismic ambient noise, we (i) model the 3‐D shear wave velocity structure of the West Antarctic crust and (ii) map variations in crustal radial anisotropy. Enhanced regional resolution is offered by the UK Antarctic Seismic Network. In the West Antarctic Rift System (WARS), a ridge of crust ∼26–30 km thick extending south from Marie Byrd Land separates domains of more extended crust (∼22 km thick) in the Ross and Amundsen Sea Embayments, suggesting along‐strike variability in the Cenozoic evolution of the WARS. The southern margin of the WARS is defined along the southern Transantarctic Mountains and Haag‐Ellsworth Whitmore Mountains (HEW) block by a sharp crustal thickness gradient. Crust ∼35–40 km is modeled beneath the Haag Nunataks‐Ellsworth Mountains, decreasing to ∼30–32 km thick beneath the Whitmore Mountains, reflecting distinct structural domains within the composite HEW block. Our analysis suggests that the lower crust and potentially the middle crust is positively radially anisotropic (VSH>VSV) across West Antarctica. The strongest anisotropic signature is observed in the HEW block, emphasizing its unique provenance among West Antarctica's crustal units, and conceivably reflects a ∼13‐km‐thick metasedimentary succession atop Precambrian metamorphic basement. Positive radial anisotropy in the WARS crust is consistent with observations in extensional settings and likely reflects the lattice‐preferred orientation of minerals such as mica and amphibole by extensional deformation. Our observations support a contention that anisotropy may be ubiquitous in the continental crust.

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Section: Tectonic Interpretation Of V Sv Modelsupporting

confidence: 85%

Section: Shear Wave (Vsv) Velocity Modelmentioning

confidence: 99%

Mapping Crustal Shear Wave Velocity Structure and Radial Anisotropy Beneath West Antarctica Using Seismic Ambient Noise

O’Donnell

Brisbourne

Stuart

et al. 2019

Geochem Geophys Geosyst

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“…Crustal structure introduces the greatest uncertainty as extrapolation of surface outcrops to half crustal thickness will overrepresent thin sedimentary basins and isolated plutons. Crustal structure may be resolvable through geophysical interpretation, as it has been in determining sedimentary thicknesses in the Weddell Sea region [ Golynsky and Aleshkova , ; Jordan et al ., ].…”

Section: Discussionmentioning

confidence: 99%

A new heat flux model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic heat production

Burton‐Johnson

Halpin

Whittaker

et al. 2017

Geophysical Research Letters

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A new method for modeling heat flux shows that the upper crust contributes up to 70% of the Antarctic Peninsula's subglacial heat flux and that heat flux values are more variable at smaller spatial resolutions than geophysical methods can resolve. Results indicate a higher heat flux on the east and south of the Peninsula (mean 81 mW m−2) where silicic rocks predominate, than on the west and north (mean 67 mW m−2) where volcanic arc and quartzose sediments are dominant. While the data supports the contribution of heat‐producing element‐enriched granitic rocks to high heat flux values, sedimentary rocks can be of comparative importance dependent on their provenance and petrography. Models of subglacial heat flux must utilize a heterogeneous upper crust with variable radioactive heat production if they are to accurately predict basal conditions of the ice sheet. Our new methodology and data set facilitate improved numerical model simulations of ice sheet dynamics.

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“…To produce our Antarctic‐wide compilation of magnetic anomalies, we used (Table S1) the following: all the publicly available aeromagnetic data for the Antarctic continent and surrounding areas: ADMAP (Golynsky et al, ), WISE (Ferraccioli et al, ), AFI‐Coats Land (Bamber et al, ), AGAP (Ferraccioli et al, ), PPT (Studinger et al, ), ICECAP (Aitken et al, ), Central TAM (Goodge & Finn, ), and Weddell Sea (Jordan et al, ); a reprocessed version of a compilation over Dronning Maud Land (Mieth & Jokat, ) and ICEGRAV2013 (Forsberg et al, ); and satellite magnetic data from the Magnetic Field Model MF7 (MF7) (Maus, ).…”

Section: Methodsmentioning

confidence: 99%

Heat Flux Distribution of Antarctica Unveiled

Martos

Catalán

Jordan

et al. 2017

Geophysical Research Letters

184

388

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Antarctica is the largest reservoir of ice on Earth. Understanding its ice sheet dynamics is crucial to unraveling past global climate change and making robust climatic and sea level predictions. Of the basic parameters that shape and control ice flow, the most poorly known is geothermal heat flux. Direct observations of heat flux are difficult to obtain in Antarctica, and until now continent‐wide heat flux maps have only been derived from low‐resolution satellite magnetic and seismological data. We present a high‐resolution heat flux map and associated uncertainty derived from spectral analysis of the most advanced continental compilation of airborne magnetic data. Small‐scale spatial variability and features consistent with known geology are better reproduced than in previous models, between 36% and 50%. Our high‐resolution heat flux map and its uncertainty distribution provide an important new boundary condition to be used in studies on future subglacial hydrology, ice sheet dynamics, and sea level change.

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New geophysical compilations link crustal block motion to Jurassic extension and strike-slip faulting in the Weddell Sea Rift System of West Antarctica

Cited by 65 publications

References 121 publications

Mapping Crustal Shear Wave Velocity Structure and Radial Anisotropy Beneath West Antarctica Using Seismic Ambient Noise

Mapping Crustal Shear Wave Velocity Structure and Radial Anisotropy Beneath West Antarctica Using Seismic Ambient Noise

A new heat flux model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic heat production

Heat Flux Distribution of Antarctica Unveiled

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