Institute of Geophysics and Tectonics (IGT) PhD Projects
Seismological Investigation of the Base of a Plate
Supervisors: Dr Doug Angus and Professor Graham Stuart
Lithospheric plates define the upper thermal boundary layer of the Earth and actively participate in upper-mantle convection and yet the coupling mechanism between plates and the upper mantle is not well understood (see Figure 1). If we are to make process in understanding how and why plate convection developed on Earth we need to know the structure of the plate and its interaction with the upper mantle.
Figure 1: Schematic diagram of the LAB.
The studentship involves modelling the anisotropic structure of lithospheric plates, specifically the lithoshperic-asthenospheric boundary (LAB), and investigating how the base of plates can be detected seismically using anisotropic reflectivity code (see Figure 2). The project will consist of two components: (1) develop a range of models characterising the rheology of continental lithosphere in terms of strain related fabric and/or partial melt that may explain seismically detected mode conversions at depths of the inferred LAB and (2) determine whether or not we can detect seismically the LAB of continental lithosphere using P - and S-wave receiver functions (e.g., Angus et al. 2006; 2009). Receiver functions (RF) provide high -resolution images of sub- horizontal lithospheric and constraining the ability of RF in detecting the base of the lithosphere will have important implications in our interpretation of seismic observation and understanding of planetary evolution.
Figure 2: Modelling seismic mode conversions using reflectivity code (Angus, 2007).
Group Members
Principal Investigator: Doug Angus
Co-Investigator: Graham Stuart
References
Angus, DA (2007) True amplitude corrections for a narrow-angle one-way elastic wave equation,GEOPHYSICS, 72, pp.T19-T26.
Angus, DA; Kendall, JM; Wilson, DC; White, DJ; Sol, S; Thomson, CJ (2009) Stratigraphy of the Archean western Superior Province from P- and S-wave receiver functions: Further evidence for tectonic accretion?, PHYS EARTH PLANET IN, 177, pp.206-216.
Angus, DA; Wilson, DC; Sandvol, E; Ni, JF (2006) Lithospheric structure of the Arabian and Eurasian collision zone in eastern Turkey from S-wave receiver functions, GEOPHYS J INT, 166, pp.1335-1346.