Jerry X. Mitrovica
My research activites encompass the measurement, analysis and interpretation of the Earth's response to forcings with a wide range of time scales. The `response' includes: Geodynamics associated with the convective circulation in the Earth's mantle; the isostatic adjustment of the Earth driven by the late Pleistocene glacial cycles and more recent ice-ocean mass transfers; and solid Earth (body) tides induced by luni-solar gravitational forcings. The research combines theoretical descriptions and numerical predictions of the response of sufficiently general planetary models with relevant observational constraints. These constraints arise from sources as varied as geological reconstructions of lithospheric dynamics, and the remarkably accurate measurement
techniques of space geodesy, particularly very-long-baseline interferometry (VLBI) and Global Positioning System (GPS) surveying. The broad goal of the research is to develop a clearer understanding of the elastic and anelastic properties of the planet, to formulate a unified description of the multitude of surface features which orignate from the Earth responses described above, and to consider the influence of these responses on global change processes.
A selection of current activities are listed below:
Solid Earth Tides: Development of theoretical descriptions and numerical predictions for the response of a laterally heterogeneous Earth model to the tidal forcing. Comparison of these predictions with VLBI and GPS determined estimates of tidal displacements at a variety of tidal frequencies. Long term tidal dissipation in the solid Earth.
Glacial Isostatic Adjustement: Application of geophysical inverse theory to the inference of rheology based upon the available data set. Analysis of the rotational and gravitational signature of the adjustment. Glaciation-induced changes in the orbital elements of the Earth. GPS surveying in Scandinavia (and consequent data anlaysis) with the intent to measure and interpret present-day (post-glacial) crustal deformation rates in the region.
Plate Tectonics and Mantle Convection: Predictions of the surface topographic expression of the time-dependent features of the mantle convective circulation (e.g., transient subduction, mantle plumes). Application of the results to explain large scale tectonic features (e.g., platform subsidence). Long-term sea-level trends. The influence of variable thermal conductivity on thermal convection.