S40RTS nesting tomography globes - "Seismic Matryoshka"

Global tomographic models of seismic velocity provide us with crucial information about the planet’s interior. Here, we represent S wave velocity variation such that slow velocities stand proud and fast velocities as depressions.

For a longer wavelength, 3 layer model, see https://www.thingiverse.com/thing:3254056.

To capture the 3D nature of tomography models (in which velocity structure varies with depth), we draw analogy to Russian nesting dolls (Matryoshkas). The outer globe can be sep