Theory

Full Spectrum Tomography

Progress in tomographic modeling is driven by diverse data, ranging from astronomic-geodetic constraints to full seismic waveforms and derivative measurements of body waves (~1 – 20s), surface waves (~20 – 300s) and normal modes (~250 – 3000s).  Full-spectrum tomography (FST) employs these observations to constrain physical properties – seismic velocity, anisotropy, density, attenuation and topography of discontinuities - in variable spatial resolution. Joint inversions account for different depth sensitivities to physical parameters and also reduce inter-parameter tradeoffs.

  • Processed and Derived Data

    Do different datasets "see" the same Earth?
    Processed and derived seismic data

    Processed waveform (Left) & spectrum (Right) at Charters Towers, Australia from MW 9.1 2004 Sumatra Earthquake. Derived data types are listed; those in yellow are array-based techniques. Do tomographic techniques that use processed versus derived measurements “see” the same heterogeneity?

  • Full Spectrum Tomography

    Full Spectrum Tomography (FST) models the full spectrum of seismic data spanning 1-3000 s to constrain different types of heterogeneity in variable spatial resolution. Average Earth data, marked by *, ensure that bulk properties of 3D models are optimized simultaneously.

  • Data sensitivity

    Seismic data sensitivity

    Sensitivity of different data sets represented by global average of diagonal elements of the inner-product matrix [GTG from Gm=dobs]. Zoomed panels for VS on the right show cumulative sensitivities for sub-types of data, & for all data combined.