Speaker: Prof Ana Ferreira, UCL
Anna Ferreira studies deep Earth structure and earthquake source processes to obtain an integrated understanding of the processes controlling the dynamic behaviour of our planet from the surface down to the lowermost mantle. Her research group develops and uses novel comprehensive methodologies for modelling seismic and, more recently, geodetic data.
Abstract: Seismic anisotropy provides key information to map the trajectories of mantle flow and understand the evolution of our planet. While the presence of anisotropy in the uppermost mantle is well established, the existence and nature of anisotropy in the transition zone and uppermost lower mantle are still debated. Here we use three-dimensional global seismic tomography images based on a large dataset that is sensitive to this region to show the presence of anisotropy in the lower mantle beneath subduction zones. We interpret the tomography images in terms of mantle flow using results from 3-D geodynamical models and mantle fabrics calculations. We then discuss three ongoing directions to enhance the imaging and interpretation of mantle anisotropy via: (i) improved waveform modelling for independent model appraisal; (ii) more integrated seismic and geodynamical analyses; and, (iii) new data from a large-scale offshore passive experiment in the mid-Atlantic.
Venue: Seminar rooms or join online via zoom link