Erosion at extended continental margins: Insights from new aerogeophysical data in eastern Dronning Maud Land

Eagles, Graeme; Karlsson, Nanna B.; Ruppel, Antonia; Steinhage, Daniel; Jokat, Wilfried; Läufer, Andreas

doi:10.1016/j.gr.2018.05.011

Cited by 17 publications

(28 citation statements)

References 54 publications

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“…Eagles et al. (2018) showed that there was also clearly activity linked to passive margin development and erosion that occurred inland of the mountains.…”

Section: Te Resultsmentioning

confidence: 99%

“…the Forster magnetic anomaly (Riedel et al, 2013) and the Gamburtsev Suture (Ferraccioli et al, 2011). However, the present-day mountains are unlikely to be that old (e.g., Paxman et al, 2016) so the Sirevaag et al (2018) and Eagles et al (2018) scenarios seem preferable.…”

Section: T E Resultsmentioning

confidence: 99%

“…As Eagles et al. (2018) note, the coast‐parallel mountains of central DML form one of the world's great escarpments, which evolved from the extended continental margin resulting from the breakup of Gondwana in Jurassic times. It has a relief of >5 km, with peaks up to 3,200 m above sea level, and is ∼200 km inland from the present margin.…”

Section: Te Resultsmentioning

confidence: 99%

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Effective Elastic Thickness Map Reveals Subglacial Structure of East Antarctica

Swain

Kirby

2021

Geophysical Research Letters

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East Antarctica is the least well‐exposed Precambrian shield on Earth. What is known, or surmised, of its geological structure comes from extrapolation over large distances and from geophysics. Here, we present a map of effective elastic thickness, Te, computed from Antarctic bedrock topography and both terrestrial and satellite gravity data. Te is directly related to lithospheric strength and can distinguish domains of differing tectonic history. Our map reveals a broad region of high Te in Wilkes Land, interpreted as a craton, while elsewhere a corridor of low Te meanders between areas of higher Te. The low‐Te belt follows the trend of prominent linear magnetic anomalies identified in the Gamburtsev and Dronning Maud Land provinces, two of which have previously been identified as possible Grenville or Pan‐African age sutures.

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“…Eagles et al. (2018) showed that there was also clearly activity linked to passive margin development and erosion that occurred inland of the mountains.…”

Section: Te Resultsmentioning

confidence: 99%

Section: T E Resultsmentioning

confidence: 99%

Section: Te Resultsmentioning

confidence: 99%

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Effective Elastic Thickness Map Reveals Subglacial Structure of East Antarctica

Swain

Kirby

2021

Geophysical Research Letters

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“…By relying on this spread in rate factors and by accounting for a possible spread in ice thicknesses around the ca. 1000 m thickness obtained from a few airborne flight lines (Eagles et al, 2018) (see Section 5), depth-averaged velocities in the order of 0.4-12 m a À1 are typically expected over the Nansen ice field (Fig. C.1).…”

Section: Appendix C Ice Dynamic 1-d Flowline Modelmentioning

confidence: 87%

“…However, the use of a 3-D ice flow model is not justified here, as various boundary conditions have large uncertainties. The best estimates on the regional ice thickness are from the BEDMAP2 dataset (Fretwell et al, 2013), and recently performed airborne radar measurements of ice thickness over parts of the ice field and its surroundings (Eagles et al, 2018). These datasets suggest that the local ice thickness is typically in the order of 1000 m around the ice field (see e.g.…”

Section: Regional Ice Flowmentioning

confidence: 99%

Unravelling the high-altitude Nansen blue ice field meteorite trap (East Antarctica) and implications for regional palaeo-conditions

Zekollari

Goderis

Debaille

et al. 2019

Geochimica et Cosmochimica Acta

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Antarctic blue ice zones, the most productive locations for meteorite recovery on Earth, contain old ice that is easily accessible and available in large quantities. However, the mechanisms behind these meteorite traps remain a topic of ongoing debate. Here, we propose an interdisciplinary approach to improve our understanding of a meteorite trap in Dronning Maud Land (East Antarctica) on the Nansen blue ice field meteorite trap (2600-3100 m above sea level), where more than half of the Asuka meteorites have been collected. Based on 185 surface blue ice samples, one of the largest observed spatial patterns in oxygen isotopic variation to date is found. Relying on meteorites for which the terrestrial ages are determined using 14 C and 36 Cl, this surface ice is interpreted to date from the Last Interglacial up to the present-day. By combining state-of-the-art satellite derived surface velocities, surface mass balance modelling and ice flow modelling, we estimate that about 75-85% of the meteorites found on the ice field were supplied by ice flow after entering the ice sheet in an accumulation area of a few hundred square kilometres located south (upstream) of the ice field. Less than 0.4 new meteorites per year are supplied to the ice field through ice flow, suggesting that the hundreds of meteorites found 25 years after the first visit to this ice field mostly represent meteorites that were previously not found, rather than newly supplied meteorites. By combining these findings, the infall rate of meteorites from space is estimated, which is in line with values from the literature, but situated at the higher end of the range. A comparison of the oxygen isotopic variation of the surface blue ice to that of the European Project for Ice Coring

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Preserved landscapes underneath the Antarctic Ice Sheet reveal the geomorphological history of Jutulstraumen Basin

Franke

Eisermann

Jokat

et al. 2021

Earth Surf Processes Landf

Self Cite

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The landscape of Antarctica, hidden beneath kilometre-thick ice in most places, has been shaped by the interactions between tectonic and erosional processes. The flow dynamics of the thick ice cover deepened pre-formed topographic depressions by glacial erosion, but also preserved the subglacial landscapes in regions with moderate to slow ice flow. Mapping the spatial variability of these structures provides the basis for reconstruction of the evolution of subglacial morphology. This study focuses on the Jutulstraumen Glacier drainage system in Dronning Maud Land, East Antarctica.The Jutulstraumen Glacier reaches the ocean via the Jutulstraumen Graben, which is the only significant passage for draining the East Antarctic Ice Sheet through the western part of the Dronning Maud Land mountain chain. We acquired new bed topography data during an airborne radar campaign in the region upstream of the Jutulstraumen Graben to characterise the source area of the glacier. The new data show a deep relief to be generally under-represented in available bed topography compilations. Our analysis of the bed topography, valley characteristics and bed roughness leads to the conclusion that much more of the alpine landscape that would have formed prior to the Antarctic Ice Sheet is preserved than previously anticipated.We identify an active and deeply eroded U-shaped valley network next to largely preserved passive fluvial and glacial modified landscapes. Based on the landscape classification, we reconstruct the temporal sequence by which ice flow modified the topography since the beginning of the glaciation of Antarctica.

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Erosion at extended continental margins: Insights from new aerogeophysical data in eastern Dronning Maud Land

Cited by 17 publications

References 54 publications

Effective Elastic Thickness Map Reveals Subglacial Structure of East Antarctica

Effective Elastic Thickness Map Reveals Subglacial Structure of East Antarctica

Unravelling the high-altitude Nansen blue ice field meteorite trap (East Antarctica) and implications for regional palaeo-conditions

Preserved landscapes underneath the Antarctic Ice Sheet reveal the geomorphological history of Jutulstraumen Basin

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