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

Zekollari, Harry, Goderis, Steven, Debaille, Vinciane, van Ginneken, Matthias, Gattacceca, Jérôme, Timothy Jull, A.J., Lenaerts, Jan T.M., Yamaguchi, Akira, Huybrechts, Philippe, Claeys, Philippe and others. (2019) Unravelling the high-altitude Nansen blue ice field meteorite trap (East Antarctica) and implications for regional palaeo-conditions. Geochimica et Cosmochimica Acta, 248 . pp. 289-310. ISSN 0016-7037. (doi:10.1016/j.gca.2018.12.035) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:88143)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
https://doi.org/10.1016/j.gca.2018.12.035

Abstract

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 14C and 36Cl, 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 in Antarctica (EPICA), Dronning Maud Land (EDML) ice core (located 750 km to the west, at the same elevation), suggests that the regional changes in topography have been relatively limited since the Last Interglacial, supporting theories of an overall stable East Antarctic Ice Sheet (EAIS) over this time period.

Item Type: Article
DOI/Identification number: 10.1016/j.gca.2018.12.035
Uncontrolled keywords: Antarctic meteorite trap; Nansen ice field; Terrestrial age; Stable isotope geochemistry; Satellite derived velocities; Palaeoclimate
Subjects: Q Science > QE Geology > QE515 Geochemistry
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Matthias van Ginneken
Date Deposited: 14 May 2021 13:46 UTC
Last Modified: 25 Jan 2022 22:21 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/88143 (The current URI for this page, for reference purposes)
van Ginneken, Matthias: https://orcid.org/0000-0002-2508-7021
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