Late Quaternary dynamics of the Lambert Glacier-Amery Ice Shelf system, East Antarctica

• Published in: Quaternary science reviews Vol. 252; p. 106738
• Main Authors: Wu, Li, Wilson, David J., Wang, Rujian, Passchier, Sandra, Krijgsman, Wout, Yu, Xun, Wen, Tingyu, Xiao, Wenshen, Liu, Zhifei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2021
• Subjects: Antarctica; Clay minerals; Glaciology; Ice sheet dynamics; Iceberg rafted debris; Lambert Glacier-Amery Ice Shelf System; Prydz Bay; Quaternary; Glaciology; Prydz Bay; Quaternary; Lambert Glacier-Amery Ice Shelf System; Ice sheet dynamics; Clay minerals; Antarctica; Iceberg rafted debris
• ISSN: 0277-3791; 1873-457X
• DOI: 10.1016/j.quascirev.2020.106738

The Lambert Glacier-Amery Ice Shelf system (LGAISS) is the largest outlet glacier system in East Antarctica but its response to past climate variability is poorly constrained. In this study, we explore its dynamics over the last ∼520 thousand years using new high-resolution sedimentary records retrieved off Prydz Bay. Episodic occurrences of iceberg rafted debris indicate a dynamic ice sheet throughout this interval, while changes in clay mineral compositions provide detailed evidence on the waxing and waning of the LGAISS. Our data indicate that advance and retreat of the LGAISS was sensitive to oceanic forcing, but also responded to local summer insolation when insolation peaks combined with interglacial sea level high stands. Subglacial bed topography may have played an additional role in modulating the LGAISS behaviour, which could explain sectoral differences in the response of the East Antarctic Ice Sheet to climate change. Overall, our records indicate that the LGAISS advanced more extensively during previous late Quaternary glacial periods than during Marine Isotope Stages 2 and 4. Furthermore, the LGAISS retreated more significantly than present during Marine Isotope Stage 13, and only moderately during Marine Isotope Stage 7, which suggests that the duration of warm climatic states could be a key factor affecting the dynamics of the East Antarctic Ice Sheet. •The LGAISS displayed dynamic behaviour throughout the past 520 kyr.•Glacial advance and interglacial retreat were mostly sensitive to oceanic forcing.•Additional modulation by local summer insolation during warm interglacial periods.•Local bathymetric features significantly affected the dynamics of the LGAISS.•Duration of warm climate states was a key factor in East Antarctic Ice Sheet retreat.