Spectral studies of gravity and topography data in the central Pacific ocean

Spectral methods of analysing the relationship between gravity and topography as a function of wavelength have the potential to provide information on both plate mechanics and mantle dynamics. Although the application of spectral techniques, such as admittance and coherence, to the continents has proved somewhat controversial, their application to the oceans has been instrumental in determining the flexural rigidity of oceanic lithosphere and its relationship to plate and load age. Previous spectral studies in the oceans have focussed, however, on windowed periodogram methods of determining a single flexural rigidity estimate, either along one or more profiles or over a "grid" of data. In this project, new spectral methods, such as maximum entropy and multi-taper, will be used to determine the relationship between gravity and topography as a function of wavelength in the central Pacific ocean. The project aim is to determine the contribution to the observed admittance and coherence of plate flexure and to isolate it from other contributions such as those associated with mantle convection. The project, which will be a collaborative one with Dr. Marta Perez, will involve the compilation of large geophysical data sets, the analysis of geophysical data using spectral techniques, and the geodynamical modelling of plate flexure and mantle convection.

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