The Law Dome ice cap and Windmill Islands, East Antarctica: a gravity-based study of ice mass balance and subglacial geology

• Main Author: Brad Bailey
• Format: Thesis
• Language: unknown
• Published: 2021
• Subjects: Other education not elsewhere classified; Ice caps; Ice caps > Antarctica; Geology; Geology > Antarctica; Gravity; Gravity > Measurement > Antarctica; Antarctic; The Antarctic; East Antarctica; East Antarctic Ice Sheet; Windmill Islands; Casey Station; Law Dome; Antarc*; Antarctica; Ice cap; Ice Sheet
• Online Access: https://doi.org/10.25949/19434647.v1; https://figshare.com/articles/thesis/The_Law_Dome_ice_cap_and_Windmill_Islands_East_Antarctica_a_gravity-based_study_of_ice_mass_balance_and_subglacial_geology/19434647

The Law Dome ice cap is a small to medium sized ice cap, approximately 200 km across, situated on the periphery of the East Antarctic Ice Sheet at 67°S 113°E. The Law Dome ice cap is separated from the East Antarctic Ice Sheet by a deep trench system, the Totten-Vanderord Trench, which diverts the flow on ice from inland around Law Dome rather than onto the ice cap. This process results in Law Dome's ice mass input, or ice accumulation regime, to solely be in the form of snowfall accumulation. Hence, Law Dome provides an ideal model to study the mass budget of ice caps in East Antarctica in the form of a relatively small ice cap allowing for feasible spatial survey coverage near a scientific research station – Australia's Casey Station. During the Antarctic summer field season of 2004/05, gravity measurements were observed across the Law Dome ice cap and adjacent Windmill Islands. The primary objective of the Law Dome ice cap gravity survey was to re-occupy previously established gravity stations to continue the time-series gravity database and deduce changes in gravity with time across the ice cap (dg/dt). The dg/dt can be directly transformed to the change in ice surface height of each gravity site (dh/dt) such that snowfall accumulation rate trends could be established dating back to the early 1960's. For consistency, the same Lacoste and Romberg G-model gravity meters which were utilised for many of the previous surveys were again used during the 2004/05 gravity survey. The secondary objective of the Law Dome gravity survey was to process the data to generate a Bouguer gravity map of Law Dome and its surrounding environs such that a subglacial geological interpretation could be inferred. A gravity survey of the Windmill Islands on the west coast of Law Dome was carried out with the aim of modelling the various subsurface igneous and metamorphic rock units of the area. III Gravity data has been collated from each of the several gravity surveys on Law Dome dating back to 1962. Where sufficient data and ...