This thesis analyses satellite-based radar data to improve our understanding of
the interactions between the Antarctic Ice Sheet and the ocean in the Amundsen
Sea Sector of West Antarctica. Over the last two decades, the European Remote
Sensing (ERS) Satellites have provided extensive observations of the marine and
cryospheric environments of this region. Here I use this data record to develop
new datasets and methods for studying the nature and drivers of ongoing change
in this sector. Firstly, I develop a new bathymetric map of the Amundsen Sea,
which serves to provide improved boundary conditions for models of (1) ocean
heat transfer to the ice sheet margin, and (2) past ice sheet behaviour and extent.
This new map augments sparse ship-based depth soundings with dense gravity
data acquired from ERS altimetry and achieves an RMS depth accuracy of 120
meters. An evaluation of this technique indicates that the inclusion of gravity data
improves the depth accuracy by up to 17 % and reveals glaciologically-important
features in regions devoid of ship surveys. Secondly, I use ERS synthetic aperture
radar observations of the tidal motion of ice shelves to assess the accuracy of tide
models in the Amundsen Sea. Tide models contribute to simulations of ocean
circulation and are used to remove unwanted signals from estimates of ice shelf
flow velocities. The quality of tide models directly affects the accuracy of such
estimates yet, due to a lack of in situ records, tide model accuracy in this region is
poorly constrained. Here I use two methods to determine that tide model accuracy
in the Amundsen Sea is of the order of 10 cm. Finally, I develop a method to map 2-d ice shelf flow velocity from stacked conventional and multiple aperture
radar interferograms. Estimates of ice shelf flow provide detail of catchment
stability, and the processes driving glaciological change in the Amundsen Sea.
However, velocity estimates can be contaminated by ocean tide and atmospheric
pressure signals. I minimise these signals by stacking interferograms, a process
which synthesises a longer observation period, and enhances long-period (flow)
displacement signals, relative to rapidly-varying (tide and atmospheric pressure)
ones. This avoids the reliance upon model predictions of tide and atmospheric
pressure, which can be uncertain in remote regions. Ice loss from Amundsen
Sea glaciers forms the largest component of Antarctica’s total contribution to sea
level, yet because present models cannot adequately characterise the processes
driving this system, future glacier evolution is uncertain. Observations and models
implicate the ocean as the driver of glaciological change in this region and have
focussed attention on improving our understanding of the nature of ice-ocean
interactions in the Amundsen Sea. This thesis contributes datasets and methods
that will aid historical reconstructions, current monitoring and future modelling
of these processes