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Defining models of glacial isostatic adjustment in West Antarctica and the Antarctic Peninsula (UKANET): Better constraints on Earth structure and uplift
A research project of the Department of Geography.
The main aim of this project is to reduce the uncertainty associated with Glacial Isostatic Adjustment (GIA) processes in West Antarctica and the southern Antarctic Peninsula by addressing the current lack of knowledge relating to Earth structure and uplift in this important region of present-day ice loss. In particular, very little is known about the crust and upper mantle structure of the region. The Earth structure information is crucial for determining the rate of rebound in response to both past and present ice-mass change; two processes that will have opposing effects on the shape of Earth’s gravity field. Separating out the contribution from these competing signals is the greatest barrier to accurately determining the distribution of present-day ice mass change in Antarctica.
This project aims to determine Earth structure through a new passive seismological experiment. A network (UKANET) of 10 broadband seismometers will be deployed in West Antarctica for 2 years to estimate 3D variations in Earth rheology. Spatial variations in seismic velocity to depths of ~400km across the southern Antarctic Peninsula and Ellsworth Land will be used to create a high resolution map of upper mantle temperatures across the region. Such a study has not previously been carried out in the Antarctic Peninsula region, and very little is known about the regional Earth structure.
The Durham-led part of the project seeks to assimilate the information on mantle temperatures into a 3D finite element model that describes the rheological properties of the Earth and computes solid Earth deformation. This will allow us, for the first time, to account for detailed spatial variations in rheology when considering the response to surface loading in this tectonically complex region. The inclusion of lateral variations in Earth structure is a key step towards more realistic GIA models.
Furthermore, rebound rate measurements from the UKANET Global Navigation Satellite System (GNSS) network, which consists of 10 GPS stations distributed across the southern Antarctic Peninsula, will allow us to better quantify the response of the solid Earth to ongoing ice sheet changes.
This is a NERC-funded project led by Graham Stuart (Leeds), and it involves collaboration between researchers at University of Leeds, Durham University and British Antarctic Survey, as well as overseas partners at University of Tasmania, TU Delft and members of the NSF-funded POLENET project.
For further information, please contact Professor Graham Stuart (University of Leeds).