Improving models of West Antarctic glacial isostatic adjustment through a new surface velocity field. This project seeks to "fix the scales" being used to weigh changes in the Antarctic ice sheet. Present measurements are biased by a failure to accurately account for mass changes beneath the ice and within the Earth itself. This project seeks to use new measurements of the changes in the shape of the Earth to calibrate out that bias.
Glacio-isostatic effects on geodetic data: Ice and sea level implications. Glacio-isostatic (GI) effects are recorded in geological and geodetic data sets and mask other deformational processes. This project builds on past work using geological data with a focus on combining geodetic and geological evidence to improve knowledge of the past ice sheets, separate out effects of past and present deglaciation and develop improved models for the mantle rheology to include time-dependencies in mantle r ....Glacio-isostatic effects on geodetic data: Ice and sea level implications. Glacio-isostatic (GI) effects are recorded in geological and geodetic data sets and mask other deformational processes. This project builds on past work using geological data with a focus on combining geodetic and geological evidence to improve knowledge of the past ice sheets, separate out effects of past and present deglaciation and develop improved models for the mantle rheology to include time-dependencies in mantle response (transient creep in the first instance). The project aims to provide a complete and predictive description of the GI effects on geodetic data, consistent with geological evidence, such that other tectonic, hydrologic and sea-level signals can be estimated free of these effects.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE150100108
Funder
Australian Research Council
Funding Amount
$190,000.00
Summary
Earth’s response to ice unloading: a unique GPS measurement from Antarctica . Earth's response to ice unloading - a unique GPS measurement from Antarctica: This project aims to deploy geophysical equipment including global navigation satellite systems within Antarctica to understand how Earth responds to changes in stress (rheology) within the crust and upper mantle (the upper ~660 km). It exploits a globally-unique natural experiment that commenced in 2002 with the break-up of the Larsen B Ice ....Earth’s response to ice unloading: a unique GPS measurement from Antarctica . Earth's response to ice unloading - a unique GPS measurement from Antarctica: This project aims to deploy geophysical equipment including global navigation satellite systems within Antarctica to understand how Earth responds to changes in stress (rheology) within the crust and upper mantle (the upper ~660 km). It exploits a globally-unique natural experiment that commenced in 2002 with the break-up of the Larsen B Ice Shelf and which was followed by large-scale ice-mass unloading and rapid surface deformation. New broadband passive seismic and geodetic deformation measurements offer the promise of resolving a dichotomy between laboratory and millennial-scale determinations of Earth rheology through uniquely studying a time-scale mid-way between these extremes, whilst further strengthening Australia's emerging expertise in polar geophysics.Read moreRead less
Establishing the reference frame using astronomical and space-geodetic observations. Australia is increasingly dependent on spatial positioning and spatial data, yet mostly relies upon international agencies and research organisations to provide regular updates of coordinates and reference frame definition used on Earth. Improving the accuracy of the reference frame definition and our understanding of errors in the space-based measurements will provide new insights for studies of the Earth. The ....Establishing the reference frame using astronomical and space-geodetic observations. Australia is increasingly dependent on spatial positioning and spatial data, yet mostly relies upon international agencies and research organisations to provide regular updates of coordinates and reference frame definition used on Earth. Improving the accuracy of the reference frame definition and our understanding of errors in the space-based measurements will provide new insights for studies of the Earth. The research will yield results in studies of national significance, such as sea level rise, the effects of melting polar regions, and crustal deformation, as well as developing Australia's expertise in exploiting observations of the Earth from space.Read moreRead less
Earthquake biases in measurements of Antarctica's sea-level contribution. This project aims to accurately determine Antarctica’s contribution to present-day sea-level. Large technique-specific systematic errors make this uncertain and controversial with the sign of change not agreed. Three of four measurement techniques rely on knowing the solid earth's changing shape or gravity field. Studies have not considered post-seismic deformation, but GPS data show that Antarctica has deformed since the ....Earthquake biases in measurements of Antarctica's sea-level contribution. This project aims to accurately determine Antarctica’s contribution to present-day sea-level. Large technique-specific systematic errors make this uncertain and controversial with the sign of change not agreed. Three of four measurement techniques rely on knowing the solid earth's changing shape or gravity field. Studies have not considered post-seismic deformation, but GPS data show that Antarctica has deformed since the 1998 Magnitude-8.2 Antarctic Plate Earthquake. This project will develop a model of these earthquakes constrained by geodetic data and use the model to estimate Antarctica's contribution to sea-level change. This should enable more confident local, national and international planning. This will benefit society through reducing the sea-level projection uncertainty.Read moreRead less