Seismological imaging of the Antarctic continental lithosphere: a review

Glimpses of East Antarctica: Aeromagnetic and satellite magnetic view from the central Transantarctic Mountains of East Antarctica

“…[32] The buried sources of the high-amplitude NW trending anomalies are most likely to be Precambrian basement older than Neoproterozoic age, based on the presence of Archean-Paleoproterozoic igneous and metamorphic rocks in the Nimrod Group, the thick high-velocity lithosphere imaged by seismic tomography in the region Morelli and Danesi, 2004;Ritzwoller et al, 2001], and the high amplitude of positive anomalies observed both in satellite data over the polar plateau and in the western end of our survey . In addition, the similarly oriented but finer-scale magnetic structure of the Nimrod basement complex (magnetic unit 1), whose magnetization was produced during Ross age metamorphism, probably reflects tectonic modification of preexisting Precambrian basement structure.…”

“…Because of the lack of continuation to a common elevation above the bed and the different flight line spacings, the amplitudes and wavelengths of anomalies from similar sources can vary from survey to survey. Despite such limitations, all of these data, combined with bed elevation [Ferraccioli et al, 2009;Lythe et al, 2000;Studinger et al, 2004Studinger et al, , 2006 and regional seismic tomography data [Morelli and Danesi, 2004;Ritzwoller et al, 2001], help to resolve critical features of the craton and outboard sequences. In particular, the western limit of the Neoproterozoic rift, and the extent of the Ross Orogen and Jurassic Ferrar dolerites can be mapped in more detail (Figure 9) than previously possible .…”

“…Despite recent advances in our understanding of the ages, kinematics and continuity of various orogenic belts within and adjacent to East Antarctica, extensive ice cover and remote access make it difficult to extrapolate isolated outcrop data from coastal areas and mountain ranges very far across the continent. Although surface wave velocity data image thick (>150 km), highvelocity (>∼5% shear wave velocity perturbation) aseismic lithosphere typical of Precambrian shields beneath much of East Antarctica Ritzwoller et al, 2001;Morelli and Danesi, 2004], they do not resolve orogenscale features. Hence, our understanding of the major crustal elements and the orogenic structures that juxtaposed them during assembly of the Rodinia and Gondwana supercontinents remains largely conjectural.…”

Altimetry, gravimetry, GPS and viscoelastic modeling data for the joint inversion for glacial isostatic adjustment in Antarctica (ESA STSE Project REGINA)

“…The Earth structure of Antarctica is characterized by a strong dichotomy between east and west, separated along the Transantarctic Mountains (e.g., Morelli and Danesi, 2004 , 2008). High geothermal heat flux is in agreement with the seismic inferences of a thin elastic lithosphere and low mantle viscosity and would favor the presence of such a DL also in West Antarctica (Shapiro and Ritzwoller, 2004;Schroeder et al, 2014).…”

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“…Ice-sheet modelers still use relatively rudimentary crustal and lithospheric models of the Antarctic continent. Although the tomographic inversion of seismological data has improved the knowledge of the lithospheric structure beneath Antarctica and surrounding ocean basins (e.g., Morelli and Danesi, 2004), its spatial resolution of the upper 60-70 km of the relevant elastic lithosphere (Ivins and James, 2005), and in particular of the boundary between continental and oceanic lithosphere, is still extremely crude. Considering that ice sheets advanced to the shelf breaks of most Antarctic continental margins during glacial maxima, the isostatic response must be directly related to the width and depths of any extended continental crust and lithosphere oceanward of the shelf, which would probably have an effect on estimates of sea-level change.…”