Modelling glacial isostatic adjustment: where are we and what’s next?

Ongoing solid-Earth deformation in response to late Pleistocene glaciation is the dominant geodynamic process in many parts of Canada. Models of this process, which have been developed and improved over many decades, play an important role in the interpretation of a range of geologic and geodetic data sets to understand drivers of past and contemporary changes in land motion, gravity and sea level. In this presentation, I will review the current state-of-the-art in GIA modelling and describe some relatively recent initiatives to improve the accuracy of these models and quantify their uncertainty such that the model output will be of greater utility to the various end-user communities. Specifically, the presentation will focus on efforts to better constrain models that include 3D Earth structure via the joint inversion of regional data sets and the use of artificial neural networks to explore the model parameter space more effectively. These aspects will be illustrated using different case studies, including one for Greenland and another for eastern Canada. The presentation will end with a look forward to some planned initiatives that will involve the joint application of GIA and hydrological modelling to better separate the influence of past versus contemporary water mass redistribution on geodetic observations of land motion and gravity changes.