The recent dynamics of Moscow University Glacier and Moscow University Ice Shelf, East Antarctica (1963 – 2022)

Abstract

Mass loss from the Antarctic Ice Sheet is dominated by ice discharge through outlet glaciers, many of which are buttressed by peripheral ice shelves. In Wilkes Land, East Antarctica, an ocean-driven increase in ice flux from several large outlet glaciers has caused accelerated mass loss over recent decades. Wilkes Land overlies the Aurora Subglacial Basin (ASB), which contains an ice volume large enough to raise global sea level by 5 m and is potentially susceptible to pervasive retreat. However, ice dynamics within some areas of Wilkes Land remain largely unstudied. This includes Moscow University Glacier (MUG) and Moscow University Ice Shelf (MUIS), which regulate ice discharge from a catchment containing 128 cm of potential sea level rise within the ASB and are subject to intrusions of warm Circumpolar Deep Water. Employing optical satellite imagery and remote sensing datasets to record changes in terminus position, ice surface velocity, ice surface elevation, grounding line location and sea ice distribution, this thesis aims to investigate the ice dynamics of MUIS and MUG between 1963 and 2022. Migration of the MUIS ice front is limited to the unconfined ice shelf region. Both MUG and MUIS exhibited negligible change in flow velocity between 2000 and 2021, and the results suggest limited grounding line retreat of 1.4 km between 1996 and 2017 (~67 m yr). Ice surface elevation remained stable from 1993 to 2010, but MUG was recorded to thin at an accelerated rate (0.86 m yr) between 2011 and 2016, and regions of enhanced surface lowering were observed to correlate with areas of faster ice flow. Overall, these findings imply that MUG and MUIS have remained largely stable in recent decades, but may be starting to exhibit the early indicators of dynamic change. It is suggested that topography exerts critical stabilising stresses on MUIS, enhancing its capacity to buttress the flow of MUG. Continued monitoring of MUG and MUIS, as well as topographically-constrained ice flow modelling, will be important in understanding the response of the Moscow University catchment to future ocean forcing.